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1944-09-01 The Loss of Jan Plesman Spitfire MJ343

Crash site: unknown, probably SW to W of Hazebrouck, Nord, F

Crash cause: shot down by enemy Flak

Name

Plesman, Jan Leendert

J.L. Plesman, 1941 Photo G. Steen Orry-la-Ville Plesman

Rank

Tijd Res Kapt Vl, F/Lt.

RAF VR 102524

Decorations

Vliegerkruis, Croix de Guerre avec Palme (posthumously)

Born

18/12/1919

Place

Gouda, NL

Squadron

RAF 322 (Dutch) Sqn Fighter Command

Ops/hr

310/277

Aircraft

Spitfire Mk. LF IXe Nr. MJ343 VL-P 'Prinses Beatrix'

Base

RAF Deanland, Sussex, GB

Mission

Ground strafing

Status

MIA, aircraft shot down by enemy Flak

age

24

Missing

1/9/1944

Place

unknown, probably SW to W of Hazebrouck, Nord, F

Known to

OGS

yes

CWGC

yes

Remarks

Son of KLM founder/director Albert Plesman

See 'Steen – een geschiedenis door Huize Groenoord' by this author

Credited with 11 V-1's shot down

Student of Technische Hogeschool Delft

Memorial

1. Runnymede, panel 203

2. Vijfluik Loenen, Gelderland, NL

3. St. George's Chapel, Biggin Hill, Kent, GB

4. Memorial plate, main building Technische Universiteit Delft, NL

5. Memorial plate, Orry-la-Ville, Oise, France

GB arrival

Engelandvaarder. Arrived spring 1942 after cycling to Perpignan, together with Geert Overgaauw. He flew in with the KLM/BOAC Lisbon-Whitchurch line.

Source: Jan Plesman diary, via Albert Plesman, 2002. No interrogation report found in the archive of the Dutch Ministry of Justice in London, NA 2.09.06

Data

Confusion

1. Crash usually, following the ORB, reported as NE of St. Omer. However, the aircraft was shot by Flak positioned about 4 miles South of Hazebrouck, 30 km East of St. Omer, and dived down from 3.000 ft.

2. Aircraft called 'Prinses Irene' in some literature

3. Mentioned as 'gesneuveld te St. Omer (Belg)' in 'Op herhaling', TU Delft, 2006 (1947)


Van 17 augustus 1941 t/m 4 maart 1942 schrijft Steen 10 brieven aan zijn vriend Jan Plesman, de latere brieven naar de basis RAF Hornchurch. Jan Leendert Plesman, geboren 18-12-1919 te Gouda, gesneuveld 1-9-1944 boven Frankrijk, in de buurt van Hazebrouck.

Jan Plesman was de zoon van Albert Plesman, de oprichter van de KLM. Hij verliet bezet Nederland op 30 december 1940 per fiets, samen met z'n vriend Geert Overgaauw. Beiden waren 2e luitenants bij de luchtmacht. Jan Plesman had het relatief grote aantal van 10 operationele vluchten gemaakt tijdens de mei-oorlog in 1940.

Dankzij beleid, en een verrekijker om Duitse troepen en wegafzettingen tijdig te kunnen zien, en natuurlijk ook veel geluk, fietsten ze zonder grote problemen in slechts enkele dagen naar Perpignan. Daar moest drie maanden op een veilige passage naar Spanje worden gewacht. Eenmaal in Lissabon aangekomen, werden ze per DC3 lijnvliegtuig van de KLM naar Whitchurch bij Bristol gevlogen. Deze unieke lijndienst kon bestaan, omdat de Duitsers er een handige mogelijkheid in zagen om spionnen in Engeland te krijgen...

Deze lijn vloog 1.600 tot 1.700 diensten in oorlogstijd. Eén keer ging het mis, toen de Duitsers meenden dat Churchill aan boord van de DC3 zou zijn. De 'Ibis' G-AGBB, voor de oorlog de PH-ALI, werd op 1 juni 1943 kansloos neergeschoten boven de Atlantische Oceaan bij de Golf van Biscaje. Vier bemanningsleden en 13 passagiers kwamen om. Zij bleven vermist. Zie ook het hoofdstuk over de buiten Nederland gevallen Nederlandse RAF vliegers.

Jan Plesman kwam terecht op RAF Ternhill, op 21 augustus 1941. En daar trof hij Govert, met wie hij eindelijk weer eens Nederlands kon spreken. Ze hebben veel tijd samen doorgebracht. Ze hadden dan ook slopend veel tijd. De opleiding verliep hen veel te traag, en het voortdurend slechte vliegweer in de winter verergerde dat nog eens.

De opleiding ging van Miles Master naar Hurricane naar tenslotte, eindelijk, de Spitfire. Plesman en Steen konden niet weten dat ze elkaar op RAF Ternhill voor het laatst zouden zien.

Plesman maakt op 23 december 1941 z'n eerste solovlucht met een Spitfire. Zijn persoonlijke logboek zou tenslotte meer dan 150 missies boven bezet gebied vermelden; het werkelijke aantal operationele vluchten was 310.

Bron: Mr. J.W.T. Bosch, 'De Militaire Luchtvaart tijdens de Tweede Wereldoorlog in Groot-Brittannië 31 mei 1940 - 9 mei 1945', zd, zp, niet gepubliceerd manuskript, Sectie Luchtmachthistorie, p.164. Dit aantal is niet door deze auteur via de ORB's gekontroleerd, en kan nog hoger zijn geweest.

Plesman vloog verreweg de meeste operationele vluchten (ops) van alle Nederlanders in RAF dienst. Na hem volgen L.C.M. van Eendenburg met 279 ops, en J. van Arkel met 214 ops. Het gemiddelde van de aan Bosch bekende Nederlandse vliegers in RAF dienst bedroeg 56 ops.

Plesman was gedreven. Hij moest en zou het de Duitsers betaald zetten. De Duitsers die zijn vader ongeveer een jaar lang in de gevangenis in Scheveningen hadden opgesloten, van 9 mei 1941 tot 11 april 1942, mede als reaktie op Jan's vlucht uit Nederland. Jan zal sterk hebben gevoeld wat dat voor zijn vader moest betekenen. Zijn vader, die de KLM opbouwde en uitbouwde tot een internationale luchtvaartmaatschappij, nu gedwongen tot nietsdoen in een gevangeniscel.

Bron: Ben van Eysselsteijn, 'Naar breeder vlucht', 's-Gravenhage, 1946, p. 402

In Jan Plesman's dagboek wordt bij herhaling geklaagd over het onderkomen van de piloten van 322th (Dutch) Squadron. Vele maanden moesten worden doorgebracht in lekkende tenten op de basis. Niet echt de manier om snaargespannen jachtvliegers, die dagelijks hun leven riskeerden, de broodnodige nachtrust te geven.

Plesman houdt de Nederlandse overheid in London hiervoor verantwoordelijk. En dat is niet onredelijk. Voor een paar duizend pond hadden de vliegers een Nissen hut, en daarmee tenminste een dicht dak boven hun hoofd, kunnen hebben.

Bron: Albert Plesman, 'Jan Plesman, a flying Dutchman', 2002. Albert Plesman is Jan's broer

Het verblijf in tenten was wellicht beleid, in voorbereiding op toekomstige taktieken. Jan Plesman heeft het niet kunnen waarderen.

De 'koekebakkers' volgens Steen waren ook 'krentekakkers' volgens Plesman. Duitse krijgs-gevangenen werden in Engeland veel beter gehuisvest. Dit klagen van Steen en Plesman is niet weg te schrijven als Nederlandse folklore. Albert Plesman drukt het zo uit:

Seldom - if ever in the history of human conflict - has a government demonstrated the kind of total indifference towards the fate of their 'finest' as the Dutch government-in-exile in London!

Vanaf 8 maart 1944 kreeg het Squadron de beschikking over Spitfires Mk. XIV; vanaf augustus 1944 de Mk. IXb. Bij het 322e Squadron wist Flight Lieutenant Plesman het respektabele aantal van 11 V-1's neer te halen, en nog een gedeeld met een andere piloot. Plesman was daarmee een van 'aces' van het Squadron, die ieder meer dan 5 V-1's wisten neer te halen.

Op 10 augustus 1944 wist Plesman de laatste V-1-kill van het Squadron te maken. Het officieel erkende aantal van dit Squadron kwam daarmee op 110 stuks.

Bron: 322 Squadron website

The Hazebrouck area had proven to be hostile to Dutch RAF fighter pilots before. On 13/3/1942 E.W. Ferwerda had to emergency land his Spitfire here, after air combat with enemy fighters. He survived the emergency landing, and was taken POW. He sat out the War in camps. A month later, on 12/4/1942, quite the same happened to A.H. Rood and B. van der Stok. Both crash-landed near Hazebrouck, and were taken POW. Rood survived the War in camps. Van der Stok was one of the few survivors of the 'Great Escape', and became a 2nd time Engelandvaarder.

On August 1, 1944, Jan Plesman was shot down by Flak in a wood South of Hazebrouck. The Operations Record Book stated Northeast of St. Omer as the crash site. Aircraft nor pilot were found. After the War, the British send out a MR&ES team to investigate. Results: case closed as unsolvable. Jan Plesman and his aircraft had vanished. That's not acceptable.

2. Searching for Plesman

1. The general plan – kindling the fire

The Jan Plesman story, including the search for his body and aircraft, could fill a book on its own. As quite a few of the other cases described in this study. This is in part controlled by the amount of data found, and that's a function of effort given as well as being lucky. Chapters in this study are filled with the results of wits, sweat & luck. In other words, this study could become twice or triple as large in content, given energy, time and luck. We do what we can. The plan is to give a lot of effort to finding Jan Plesman. He is the most well known of the Dutch RAF aviators who went MIA. He went MIA over land, making it relatively easier to find him back, as compared to those who were lost over sea. Succes in finding back Jan Plesman could generate the tail wind needed to do something about at least a few of all those other cases. MIA's who fell over land first, and then those who fell at sea. Agreed, it is all highly ambitious. But it is exciting too, the excitement of the hunt. And we may have a few results. In any case, we feel that we need to try. That others failed to come up with results earlier is no deterrent. We just may have a few original ideas about how to proceed, and we may have a bit more luck. Even if Government agencies are more sluggish about the subject matter than they were shortly after Word War 2. We shall go to Government archives, but also to the eyewitnesses remaining, and we shall rely on private initiative rather than Government action. Jan Plesman & aircraft were swallowed by, and disappeared in, French soil. The impact may be a pin point on a WW2 aerial photograph dotted with bomb craters, or a slight discoloration of crops in a field on a present-day aerial photograph. A trained sniffer dog may smell the aviation fuel from his aircraft buried six meters beneath the surface. We intend to find that proverbial needle in a haystack. Below follows a chronological account of this undertaking. Scenario's about the crash site, and tools for wreck recognition without a full excatavion are developed, and then modified as data comes in and as understanding grows. The effort started as an undertaking of author alone. It resulted into a multi-person, multi-organisation affair. The fire was kindled, and it burned. The story is filled with emotions ranging from high expectations to deceptions, as we probe deeper into the mystery of the loss of Jan Leendert Plesman. We describe a now-or-never effort.

2. First efforts - Archives and literature

St. Omer en wijde omgeving werden door de Duitsers stevig verdedigd met luchtafweergeschut. In Helfaut-Wizernes, enkele kilometers zuidwest van St. Omer, werd vanaf september 1943 door de Duitsers gebouwd aan een reusachtig ondergronds bunkercomplex. Hier moesten V2 raketten worden gebouwd en afgevuurd. Het complex is er nog steeds, nu als Museum 'La Coupole', naar de grote betonnen koepel die boven de grond uitstak. Tegen het einde van juli 1944 verlieten de Duitsers het complex, daartoe krachtig aangezet door zware geallieerde bombardementen.

Bron: website www.lacoupule.com

Plesman vloog Spitfire Mk. IXb Nr. MJ343 VL-P. Roepletter 'P for Plesman', en de naam 'Prinses Beatrix'. Tijdens de laatste vlucht werd Plesman's Spitfire volgens Albert Plesman geraakt door vuur van een 'Flak-trap', een trein met enkele wagons vol aanvankelijk verborgen luchtafweergeschut. De staart van de Spitfire werd eraf geschoten; het toestel raakte onbestuurbaar. Vanaf 3.000 voet hoogte dook het toestel de grond in. Een parachute is niet gezien. Er wordt vermoed dat Jan Plesman ook zelf was geraakt.

Bron: Albert Plesman, 'Jan Plesman, a flying Dutchman', 2002, waarin een geromantiseerde weergave van Jan's leven, en van de laatste vlucht, staat.

Author points out that spinning down from 3.000 feet leaves a Spitfire pilot very little opportunity and time to get out of the aircraft. There is no need for the hypothesis, formulated by Albert Plesman, that Jan Plesman himself was hit.

Vanaf 21 augustus 1944 vloog het 322e Squadron vanaf de basis RAF Deanland in Sussex. Het Squadron Operations Record Book over de dag waarop Jan Plesman sneuvelde:

1 september 1944

Today is doubtless the blackest the Squadron has ever experienced. At 07.12 hours the Squadron took off on an armed reconnaissance in the CALAIS-GHENT-AULNOYE area during which 4 M.E.T. and 1 light A.F.V. were destroyed and one heavy A.F.V. and one M.E.T. were damaged. Whilst going down to shoot up something he had seen, the C.O., MAJOR KUHLMANN D.F.C. was apparently hit by Flak and he baled out. His No.2 however saw him land and wave his hand. He landed about 5 miles inland from CAP GRES NEZ.

This is a terrible blow to the Squadron and we can only hope that he will find a way of evading capture, and eventually make his way back to take charge of the Squadron he has led so admirably. This was not the end of the bad news today for at 10.27 the Squadron again took off on an armed reconnaissance in the same area during which a gun post was attacked and 2 M.E.T. damaged. This time however, two aircraft were hit by Flak with the result that 'A' Flight Commander, F/LT. VAN EENDENBURG made a belly landing South East of Lille. The aircraft was seen to tip up and a wing break off, but he was not seen to get out of the aircraft. The 'B' Flight Commander, F/LT. PLESMAN was seen to have his tail plane shot off and he spun in North East of ST. OMER, and he was not seen to leave his aircraft. Thus it is that we have lost in one day, the C.O. and both Flight Commanders. Mere words could not possibly express the feelings of the Squadron at this moment and we shall anxiously await further news.

In de 'Details of work carried out' wordt nog vermeld dat F/Lt. Plesman met het Squadron voor deze tweede sortie was opgestegen om 10.15 uur. De andere zeven piloten kwamen tussen 11.45 en 11.50 terug op RAF Deanland.

Bron: 322th Sqn Operations Record Book, Public Record Office, London

Commanding Officer Major K.C. Kuhlmann DFC werd gevangen genomen. Flight Lieutenant L.C.M. Van Eendenburg werd verborgen door een boerenzoon. Na korte tijd werd St. Omer bevrijd, en Van Eendenburg was in staat om aan de Geallieerden 22 krijgsgevangenen te overhandigen… Op 12 september 1944 was hij weer terug bij het 322e.

Bron: L.C.M. van Eendenburg, 'Une semaine en France', reprinted & translated into french in Hugues Chevalier, 'Crashs sur le Pas-de-Calais, Lillers, 2006, page 236

The first sortie of this day was flown with 12 aircraft:

Major K.C. Kuhlmann DFC in 'G' - missing

F/Sgt. M.J. Janssen in 'D'

F/O. R.F. van Daalen Wetters in 'J'

F/Lt. L.C.M. van Eendenburg in 'E'

F/O. R. Groeneveld in 'K'

F/O. L.M. Meijers in 'B'

F/O. J.B. Arts in 'L'

F/Lt. J.L. Plesman in 'P'

F/O. M.L. van Bergen in 'U'

F/O. F.J.H. van Eijk in 'R'

F/O. L.D. Wolters in 'N'

F/Sgt. G.J.H. Dijkman in 'W'

F/O. F.J.H. van Eijk and F/O. L.D. Wolters would be killed in action at a later date.

The second sortie of this day was flown with 9 aircraft:

F/Lt. J.L. Plesman in 'P' - missing

F/O. C.R.R. Manders in 'Y'

F/Sgt. H.C. Cramm in 'Z'

F/Sgt. G.J.H. Dijkman in 'W'

F/Lt. L.C.M. van Eendenburg in 'E' - missing

F/O. J. Vlug in 'L'

F/Lt. W. de Wolff in 'K'

F/O. F.W. Speetjens in 'J'

F/O. L.M. Meijers in 'D'

F/Lt. J.L. Plesman, F/Lt. L.C.M. van Eendenburg, F/O. L.M. Meijers and F/Sgt. G.J.H. Dijkman had flown on the first sortie too. F/Sgt. H.C. Cramm and F/O. J. Vlug would be killed in action at a later date. Therefore, five of the seventeen 322 Sqn aviators airborne on 1/9/1944 would be killed in action during the War.

Source: 322th Sqn Operations Record Book, AIR 27/1716, Public Record Office, London

Een Flak-trap is een verborgen opstelling van luchtafweergeschut bij een voor jachtvliegers verleidelijk doel. In dit geval zou dat de trein zijn, en in het bijzonder de locomotief. Het afweergeschut was verborgen in een gewone goederenwagon. Het bestond meestal uit een 2cm, soms een 3,7cm Vierling, vier snelvuurkanonnen op een draailafette. De 2cm kanonnen vuurden elk met 900 schoten per minuut. Deze wapentoepassing, die nauwelijks in de gespecialiseerde literatuur is beschreven, bleek zeer gevaarlijk. Tijdens de jageraanval werden op het allerlaatste moment de wanden van de wagons geopend, om op de aanvaller te vuren. De jager had dan geen mogelijkheid meer om de koers te korrigeren. De Duitsers wisselden de positie van Flakwagons, voor, midden of achter in een treinstel, opdat de geallieerde jagers niet van tevoren konden vermoeden welke wagon levensgevaarlijk zou kunnen zijn. Als deze luchtafweer raak schoot, dan had de jachtvlieger bijzonder weinig kans om het er goed vanaf te brengen. Zie ook het verslag van de Engelandvaarder Mr. R.J.E.M. van Zinnicq Bergmann, die als Typhoon piloot enkele kollega-vliegers naast zich aan Flak-traps verloor.

Bron: Mr. R.J.E.M. van Zinnicq Bergmann, 'Het doel bereikt', Leiden, 1990, p. 188 ev.

Mr. Van Zinnicq Bergmann overleed op 15 juni 2004 in Vorden.

Of Jan Plesman werkelijk door een 'Flak-trap' in een trein is neergehaald, valt te betwijfelen. In de Casualty Files van de RAF is er een brief van de Officer Commanding No. 322 Squadron aan het Air Ministry:

'On 1st September, 1944, No. 322 Squadron, led by F/Lt. Plesman was detailed to carry out a ground strafeing mission in the Calais/Ghent/Aulnoye area. F/Lt. Plesman was flying over wood, 4 miles south of Hazebrouck at an approximate height of 3000 feet. He flew over the wood on a northerly course, the time being 11.20 hours approximately. Suddenly Flak which was concealed in the wood opened fire on F/Lt. Plesman, and he received a direct hit in the rear end of the fuselage. The aircraft went into a left hand turn, dived down with smoke and flames pouring out and crashed into the ground north east of St. Omer. F/Lt. Plesman was not seen to bale out.'

Source: RAF Air Historical Branch, from the Hayes archive with Casualty Files, letter Mrs. Susan Dickinson RAF AHB dd. 18-5-2004. On 29/6/2006 it transpired that this document is the 'circumstantial report', submitted by Plesman's wingman, F/Lt. W. de Wolff. The document is now present in the SLH archive. Erwin van Loo has recentlydiscovered it in the Nationaal Archief, archief Ministerie van Oorlog. Source: Erwin van Loo

Mrs. Dickinson van de Air Historical Branch heeft nog iets meer informatie:

'Although these eye-witness accounts were very specific in the location of the crash of Spitfire MJ343, the Missing Research & Enquiry Service were unable to discover the whereabouts of the aircraft. They also failed to find a grave for F/Lt. Plesman. The enquiries into the loss of Spitfire MJ343 were ongoing until 1948 but in view of the lapse of time and lack of evidence, the case had to be closed as insolvable.'

Ook het graf van Jan Plesman is onbekend gebleven. Volgens Plesman's broer Albert, in zijn boek over Jan, heeft de Nederlandse overheid niets ondernomen om Jan's graf te vinden.

Bron: Albert Plesman, 'Jan Plesman, a flying Dutchman', 2002

Jan's vader Albert Plesman is na de oorlog naar St. Omer gegaan om navraag te doen. Zonder resultaat.

Bron: Albert Plesman, gesprek dd. 13/6/2003

We twijfelen er niet aan dat vader Plesman destijds aan de lokale authoriteiten vragen heeft gesteld. Daar is dus niets uitgekomen. We hopen dat de officiële stilte niet een onofficiële expeditie naar oude metalen toedekt.

Alle bronnen volgen het Operations Record Book van het 322e Squadron, als ze 'noordoost van St. Omer' als de vermoedelijke crashplaats aangeven. Maar de commandant van het Squadron berichtte aan het Air Ministry over Hazebrouck, 30 km oost van St. Omer, als de plaats waar Plesman werd getroffen.

Plesmans Spitfire VL-P for Plesman is also called 'Prinses Irene' in some literature. This picture shows that the proper name was 'Prinses Beatrix'. Source: 322 Squadron website

Plesmans Spitfire VL-P for Plesman is also called 'Prinses Irene' in some literature. This picture shows that the proper name was 'Prinses Beatrix'. Source: 322 Squadron website

The St. Omer area was highly dangerous for Allied aircraft. On 30/8/1944, two days before the loss of Jan Plesman, F/O. M.A. Muller in Spitfire VL-V, was hit by Flak and had to bale out 10 to 15 miles Southeast of St. Omer. That's in the direction of Hazebrouck. F/O. Muller managed to evade captivity. He returned to 322's base already on 11/9/1944, also bringing the good news that F/Lt. Van Eendenburg was safe and back in London.

3. Second efforts – the case-tailored plan

28/6/2003

After several earlier exchanges, author outlines a plan to Albert Plesman in Rome, for finding back his brother. The plan includes archive research, finding local eyewitnesses, and finding aerial photographs of the area taken shortly after 1/9/1944. A request is send out to Keele University, England, where RAF aerial photographs are kept. This request did not receive a response.

3/7/2003

Author requests information about the Plesman crash, from the Mayor of St. Omer. It is suggested that the local newspapers could be used to ask eyewitnesses to come forward. It transpires that the request was passed on to Mr. Yves Le Maner, director of the 'La Coupole' Museum in nearby Wizernes. Mr. Le Maner saw to newspaper articles, but received no response.

1/12/2003

Op verwijzing van de secretaris van ZKH Prins Bernhard wordt de militaire attaché, verbonden aan de Nederlandse Ambassade in Frankrijk, gevraagd om zijn authoriteit in te zetten om informatie uit lokale Franse overheden, en uit het archief van de Gendarmerie, te krijgen. Dit archief is openbaar. De attaché zou met enkele telefoontjes de klus geklaard kunnen hebben. Er lijkt meewind te zijn. De ouders van de attaché blijken goede vrienden van Govert's broer Wim en ega Tinie te zijn geweest. Ze hebben elkaar in het jappenkamp leren kennen. Hun zoon, de attaché, blijkt een oude bekende van Gustaaf en Willem Jan Steen, zonen van Wim en Tinie, te zijn. De attaché wordt exakt aangewezen in welke folder in dat archief gekeken zou moeten worden. Maar ook dat hielp niet. De officials blijven bewegingsloos. Albert Plesman's stelling, dat de Nederlandse overheid niets heeft ondernomen om Jan's graf te vinden, is versterkt.

6/4/2004

Yves Le Maner bericht dat een oproep in de lokale krant van St. Omer, L'Indépendant, geen resultaat heeft opgeleverd.

18/5/2004

Information from Plesman's Casualty File is received from the RAF Air Historical Branch. The Flak that shot Plesman was located in a forest 4 miles South of Hazebrouck. This leads author to believe that St. Omer is the wrong area. Northeast of St. Omer is how it may have looked, to Allied aviators flying at high speed over enemy held territory, and headed NE of St. Omer. Deviations of up to 50 kilometers are not uncommon in their reports. Jan Plesman more likely crashed South of Hazebrouck, which is 30 kilometers East of St. Omer. His aircraft received a direct hit, and dived down in a left turn. He was flying at an altitude of only 3.000 ft. Diving in very shortly after his tail was shot off, he cannot have remained airborne for more than a dozen seconds. That means that he must have crashed close to the wood in which the Flak was positioned. If he had a horizontal airspeed of 500 to 600 km/h, then we can estimate that he crashed one or two kilometers North of the forest, South to Southwest of Hazebrouck.

Mr. Albert Plesman is informed of this by phone. Mr. Yves Le Maner is asked to repeat the newspaper operation in the search for eyewitnesses, but now in the Hazebrouck area. Again, this newspaper effort yielded no results.

4. Map of assumed crash area, version #1


Map 93. Assumed crash area of Jan Plesman, version 1

The information from the RAF Casualty Files places the Flak that shot Plesman in a forest 4 miles South of Hazebrouck. That would be the Forêt de Nieppe, 4 miles South of Hazebrouck city center. This, and Plesman's speed, altitude, heading, and the report about his final flight movements as seen by his wingman F/Lt. W. de Wolff, lead to the assumption that Plesman may have crashed in the area encircled in this map.

Hazebrouck, 2.5423E/50.7053N, near the junction of the railway and the Rue de la Motte aux Bois, looking South towards the La Motte aux Bois forest. See map above. Author believes that Jan Plesman may have crashed in this area. Hazebrouck 050702-2

One of the paths into the wild La Motte aux Bois, at the junction of Rue du Bois and Rue de la Papote. Easy to roll in an 88mm Flak gun on wheels. The local mosquitos must have feasted on the German Flak crew. Hazebrouck 050702-1

5. Air France-KLM becomes involved

16/6/2005

Een opgewonden Albert Plesman belt op. Enkele maanden geleden heeft hij de direkteur van Air France ontmoet, Jean Cyril Spinetta, en om aktie gevraagd om tenminste een zoektocht naar zijn broer Jan op touw te zetten. Nu gaat er iets gebeuren. Air France heeft een hoge official vrijgemaakt, om te gaan speuren in de Britse archieven en in Frankrijk. Het spoor is nu richting Hazebrouck. Twee jaar geleden zijn Air France en de KLM gefuseerd. Voor Air France zou het publiciteit van de eerste orde geven, als de zoon van KLM oprichter Plesman in Frankrijk, eindelijk, zou kunnen worden teruggevonden. In ieder geval zijn er nieuwe krachten vrijgemaakt, vanuit een nieuwe hoek, om de vermissing te onderzoeken. Destijds heette het 'case closed as unsolvable'. We zullen zien.

As it transpired a year later, again a newspaper article appeared, now dated June 24th, 2005, and now as a result of the envisaged Air France-KLM effort to find Jan Plesman. A more extensive article, including a picture of the aviator. And that led crash eyewitnesses to come forward. Plesman's Spitfire was not the only aircraft that came down in the St. Omer to Hazebrouck area. So the process begins of matching statements from eyewitnesses with crash data that is known or believed to be known.

Hazebrouck 060609-expo-9

20/6/2005

Albert Plesman receives a letter from Jean Spinetta. Research has been done in the archive of the Gendarmerie of St. Omer.

"As this research proved fruitless, it was extended to other districts neighbouring on Saint-Omer. Furthermore, information concerning the conditions under which Jan's Spitfire was hit, the exact location of the crash, and the mission report written by the other members of his team, were requested from the RAF's Historical Archives Department.

We are also expecting information from the Archives Department of the French Red Cross based on reports from nurses-parachutists-first aid workers responsible for burying soldiers in 1944.

Even if, however, the research undertaken with the Gendarmerie, the RAF and the French Red Cross concurs that the aircraft crashed in the region north-east of Saint-Omer, it will nevertheless be difficult to locate the aircraft as this area has a lot of marshland, and the aircraft could have sunk very deep at the time of impact without burning.

Furthermore, the Town Hall of Saint-Omer has confirmed the presence of six fighter pilots shot down and buried as "unknown" in the Saint-Omer military cemetery during the period from the end of August 1944 to mid-September 1944. We are waiting for information on the exact place they were found."

This bit of information from the St. Omer Town Hall was unfortunately not given when author requested information from St. Omer two years ago. Author hopes that the Air France people shall be interviewing elderly people in the area directly SW of Hazebrouck. An eyewitness of the crash is needed to direct to the crash area.

26/6/2005

Author submits all available data directly to Air France-KLM. No response was received.

6. First results

11/8/2005

Ten minutes before author meets Albert & Tita Plesman in The Hague, Albert receives a phone call from Mr. Jean-Pierre Moille, the Air France-KLM official charged with the search for Jan Plesman. A propellor has been found near the railway, running NW of La Motte aux Bois near Hazebrouck. The railway runs 20 meters NW of the position from which the La Motte aux Bois photograph, above, was made. Furthermore, an unknown Allied casualty has been buried locally, on 3/9/1944. Details about Jan Plesman's size and hair colour are requested. The information leads to many questions, but we may have a promising start of what could lead to a retrieval of the airman's remains.

2/1/2006

Letter to Albert Plesman, with the request to transmit to Air France-KLM:

J.L. Plesman is one of eight Dutch aviators, serving with the British Royal Air Force during World War 2, who went and remained missing-in-action over land. This fate fell to 3,4 % of all Dutch RAF aviators lost in Europe during World War 2. Neither the aircraft wreck, nor Plesman's remains, have been found. There are reasons to believe that four others are buried as unknown Allied airmen in graves in France and Germany. Author has recently requested the Chief of Staff, Royal Dutch Airforce, to open a forensic investigation into the contents of one of these graves in France, case supported by a 30 page document.

Author has produced the relevant lines in the accident report written by Plesman's Commanding Officer shortly after the day that Plesman was lost. Author has also produced the relevant lines in the report of the British Missing Research and Enquiry Service (MR&ES), that investigated these losses during the 1945-1950 period. Relevant lines quoted to author by RAF archive staff, as this archive remains closed to the year 2040. This led to a redirection of the search area from St. Omer to South of Hazebrouck, France.

Author has searched the relevant archives in Holland, in particular the archive of the Dutch Dienst Berging en Identificatie 1945-1960 (Salvage & Identification Service), and in particular the folder on losses and graves of Dutch soldiers in France. This archive holds copies of reports made by the British MR&ES and the Imperial War Graves Commission, and of the American Grave Registration Units, about Dutch soldiers, including Dutch RAF aviators, found buried in France shortly after France's liberation. Not a word was found about J.L. Plesman.

One Dutch archive remains, in which some data about J.L. Plesman might be present. This archive is closed until the year 2020. Author shall ask a special licence for access from the Dutch Minister of Defense.

In the light of this, and pending new information, and considering the circumstances of the crash as seen by other Dutch RAF pilots flying there that day, author sees two possibilities:

1. Either the wreck was found, and removed illegally because of the value of the wreck's metal. If true, then there is little hope to recover the wreck, or any human remains. Illegally, because the Germans usually buried Allied airmen's remains decently, usually close to the crash site, and usually with a makeshift wooden cross, even if they could not establish the aviator's identity. Under the pressure of the Invasion things may have been different, and the Germans may have chosen to ignore the wreck and its human contents.

2. Or the wreck was not found. The aircraft dived in from an altitude of 3.000 ft, meaning that, in the soil of Northern France, the wreck may have buried itself several meters deep. The aircraft would fold up under the forces of impact to a size of little more than that of the engine. If this would have happened in the Forêt de Nieppe, which was found in 2005 to be almost unsurpassable because of heavy undergrowth, then the crash site may have remained unnoticed.

The pilot was not seen to jump out of his aircraft, let alone that a parachute was seen. It has to be considered that the forces of impact would virtually destroy the pilot's body. Chances that the body would be thrown clear of the aircraft upon impact are very small. This in fact has happened on occasions, but not in association with a vertical dive into the ground. Bodies were thrown clear of aircraft wrecks as a result of the explosion of aviation fuel. Jan Plesman's aircraft may not have had a fuel explosion on impact, his wingmen did not see fire on the ground after impact, and that could be part of the explanation why the wreck was not found at the time. No plume of smoke to point to a downed aircraft.

Obviously it is one of the proper investigative techniques to try to find graves of unknown Allied airmen in the St. Omer-Hazebrouck area, and to try to match burial and other data regarding such graves to the loss of J.L. Plesman. However, author believes that the remains of J.L. Plesman shall be found, if at all, then with the wreck of his Spitfire.

Finding this wreck means tapping local memory, via interviews with elderly people, mostly farmers. Author has used this basic technique with excellent results on several similar occasions, and hopes that AF-KLM staff shall use their knowledge of the French language to do quite the same.

Furthermore, the RAF may have taken aerial photographs of the area in the period shortly after the crash. Photographs taken in the ongoing process of reconnaissance. These may reveal crash sites that may have passed unnoticed. These photographs are kept at Keele University in England. Author has twice send a request to Keele for such photographs. Keele University did not respond.

2/1/2006

A third request for aerial photographs is send to Keele University. As usual, no response.

7. One fighter aircraft & pilot found – a Messerschmitt

19/4/2006

Albert Plesman reports. The Air France-KLM search party has reported by phone again, about progress that has been booked. An extensive search for eyewitnesses has been made. Magnetometric equipment is used, capable of detecting metal up to a depth of 8 meters. The search has been focussed on a 2 km square area near Hazebrouck. Two fighter aircraft were discovered so far, a Spitfire and a Messerschmitt Bf-109. The remains of a Canadian airman were buried as an unknown in one of the nearby cemeteries. Research reveiled that he was the Spitfire pilot. Details are not yet available, but that would be one MIA casualty that can now be given a name. Hopes are high that the Plesman Spitfire shall be found too.

However, it transpired later that the Spitfire was not found as a result of the AF/KLM search.

The matter was reported in local newspapers in April 2006. From these:

Vijftig meter noordoost van de hoek van de Chemin du Prince en de Rue de la Caneweele, Hazebrouck, Nord, France, is op een diepte van 6 meter het wrak van een Bf-109 gevonden. Dat is 2 km noordwest van het gebied aangewezen op m'n kaart, die ik aan AF-KLM heb gegeven.

Het toestel is met hoge snelheid in de grond gedoken, dus alles stuk, maar wat er rest bleek in vrij goede konditie. De piloot zat er nog in. Er zijn persoonlijke spullen van hem aangetroffen, inklusief z'n identifikatieplaatje, Nr. 68454-173, en de verwachting is dat een identifikatie niet lang meer zal duren. In reality, the pilot's name was known straight away, due to the multitude of personal documents found in the wreck. Documents that were in very good condition. But the name, Horst Seemann, was witheld from the press, because family had to be traced first.

Uffz. Horst Seemann, flying with 9./JG1, reported MIA on 4/9/1943.

Source: Eric Mombeek

De ontdekking is gedaan door het AF-KLM team, opgericht met het doel om Jan Plesman terug te vinden. Dit team is ingesteld in juni 2005. Het wordt geleid door Jean-Pierre Moille, die in AF-KLM het kontakt met de franse luchtmacht als portefeuille heeft. Generaal René Perret van de franse Luchtmacht heeft de supervisie. Er wordt samengewerkt met Yves Le Maner, direkteur van 'La Coupole' in Wizernes bij St. Omer. La Coupole is een reusachtige duitse bunker waar de Duitsers V-2's wilden bouwen en lanceren. Het is nu een museum. Ik heb in september 2003 kontakt met hem gehad. Mijn verzoek was het via de plaatselijke kranten oproepen van ooggetuigen van crashes in de buurt. Daar kwam toen niets uit. Inmiddels zijn er 15 ooggetuigen gevonden.

De info hierboven komt uit recente krante-artikelen in plaatselijke bladen. In beroerde kopiekwaliteit ontvangen van Albert Plesman. Hieronder een bericht aan Yves le Maner. Want we willen een beetje beter op de hoogte worden gehouden. Ik meende dat AF-KLM de kwestie toegedekt wilde houden, totdat ze Plesman hadden gevonden. Dan zou er geen bericht zijn als ze zouden falen. Maar de boel staat in de krant in Frankrijk. Dus dan mogen wij ook wel iets meer horen.

Letter to Yves le Maner, director of La Coupole, Wizernes, France, 9/5/2006:

Chèr Monsieur Le Maner,

We first discussed the possible retrieval of Jan Plesman in the St. Omer area on 17 sept 2003. On my request, via the local newspapers you asked eyewitnesses to come forward. First in St. Omer. Then, when I had found the RAF Casualty File data on Jan Plesman, in Hazebrouck. As that data made clear to me that earlier searches had been made in the wrong area. Jan Plesman most likely crashed directly South of Hazebrouck.

When Mr Albert Plesman of Rome, whom I have given all information found, managed to interest the top of AF-KLM in the matter, things accelerated. I now understand that AF-KLM did indeed follow my written advise, dated 26/6/2005, to contact you. I also understand that results have been booked, in the shape of one Bf-109 & pilot found. That's first class news, even if it is not - yet - the news we hope to hear.

Meanwhile I would appreciate it if you would keep me informed about such progress. For instance via copies of newspaper articles about the matter. The reason for that is as explained before. Jan Plesman is one of 90 Dutch RAF aviators, who went and remained missing-in-action. To find these men back, if at all possible, a lot of help is needed. Results booked in France would help to persuade the Dutch authorities to become more active in these matters.

Two of the missing Dutch RAF aviators may well be buried as unknown RAF airmen in Cherbourg. I have send a report about this case to the Royal Dutch Airforce, with the request to identify the remains in these graves with modern means. Once a positive action has been achieved in the Cherbourg case, I shall submit more of these reports to the Dutch Airforce.

What's happening in Hazebrouck is an excellent example of what can be achieved if there is a will to do so. That's the message that I wish to convey to the officials in Holland, and your information would help me with that.

Have visited La Coupole in February this year. I could see your hand in the exhibition, and I was most impressed by it.

22/5/2006

A response is received from Yves Le Maner. He reports that AF/KLM is preparing an exposition in Hazebrouck, of the Messerschmitt parts found, hoping that this shall lead to more eyewitnesses coming forward. He also places author into direct contact with Jean-Pierre Moille. Author enquires if AF/KLM has asked Keele University for aerial photographs of the area, taken on or shortly after 1/9/1944. As these may hold the key to find the wreck of Jan Plesman's aircraft:

I have send three written requests to Keele University in England, where the WW2 aerial photographs taken by the Royal Air Force are archived. The request is for photographs taken of the Hazebrouck area on or shortly after 1/9/1944, when Jan Plesman was lost. The idea is that Plesman may have crashed in one of the Hazebrouck woods, which might explain why his crash site was not found at the time. I have found the woods South of Hazebrouck to be very dense, with a lot of undergrowth. Assuming that this may also have been the case in 1944, and assuming that Plesman's aircraft, that was not seen to be on fire when going down, may not have been on fire on the ground, then it is easier to understand that the wreck escaped notice. If true, than aerial photographs might reveal a crash location. If not true, then still we wish to see such photographs.

This was conveyed early January 2006 to Mr. Albert Plesman in Rome. I'm not sure whether he reported this to the AF-KLM team. I am sure that the AF-KLM does not need my advise regarding RAF aerial photographs. In any case Keele University did not respond to my requests. I hope that AF-KLM has made, or can make, a stronger request for such photographs, as I'm sure that these exist. These photographs may hold the key that is needed to conclude the Jan Plesman case.

On 23/5/2006 Yves Le Maner answers:

Merci pour votre message du 22 mai. C'est une excellente idée que de rechercher des photos aériennes de la RAF auprès de l'université de Keele.

J'espère qu'Air France sera en mesure de faire bouger les choses de ce côté. L'union fait la force !

So RAF aerial photographs have not been requested by the AF-KLM team. Let's hope that this shall yet be done, and lead to results.

8. Going places – a walk through a forest

9/6/2006

Author visits the area where the Messerschmitt has been found. The field has been levelled after the excavation. The landowner, Mr. Claude Fleuri, who has his farm at the corner of the Chemin du Prince, has taken pictures of the dig. The crash hole smelled of high octane aviation fuel, and he has kept some of that. Another helpful piece of the jig-saw puzzle, as shall transpire later.

Chemin du Prince, corner with the Rue de la Caneweele, in La Caneweele, also called La Canewelle, a hamlet directly West of Hazebrouck. The Messerschmitt has been found in the Northwest corner of the field behind the roadsign, visible in this picture as left of the roadsign. Caneweele 060609-1


The aircraft dived down almost vertically. The moving mass came to a halt 6 meters down in a layer of clay, that conserved aircraft parts, and that held some of the aviation fuel in place. The yellow patches are deposits of fuel. Caneweele Me109 dig-10. Photo Claude Fleuri

There is a small forest South of this crash site. We see a curious stone structure in a field at the edge of the forest. That calls for an investigation. The footpath towards the forest shows reinforced concrete fence poles, now broken, could be German.

Footpath towards the forest. Caneweele 060609-4

In the forest we find a virtually complete German V-1 launch site. Derelict of course, and some of the bunkers smashed by aerial bombs, but most of the buildings that make up such a facility, are still there. Several water-filled bomb craters tell their story too. The forest is called the Forêt Domaniale de Nieppe, Canton des Huit Rues, or Forêt des Huit Rues for short.

One of the several specialized bunkers in the Caneweele forest. They add up to a V-1 launch site. The bunker above, measuring about 22 x 8 meters, was intended for initial assembly of the missiles. Caneweele 060609 V-1 site-9

The curious structure seen earlier from the road are the protective walls, erected in masonry, of a launch ramp directed towards London.

V-1 launch ramp protective walls, directed at London. Caneweele 060609 V-1 site-10

This site, that was overrun by the Allied forces before it could become operational, was no doubt defended by Flak. It now becomes obvious why the AF-KLM team has searched here. We have a forest, and we most likely have a Flak site. There must have been eyewitnesses who have directed the magnetometric search to this area. An aircraft has indeed been found, and it seems to have crashed under circumstances quite comparable to the Jan Plesman crash. Both aircraft dived in almost vertically. The Messerschmitt found has not been on fire, its fuel is still present at the wreck site. The wreck and its aviator remained missing-in-action, over land, same area, for more than sixty years.

9. Adding it up - Plesman's assumed crash situation

This findings in and near the Caneweele forest lead to the following preliminary conclusions about the crash circumstances of Jan Plesman:

1. We seem to have special conditions in the soil here. The German aircraft dived in, and the weak soil swallowed and buried the wreck. Hence no fire, because no oxygen to sustain a fire.

2. A clay layer stopped the moving mass at a depth of about six meters. This clay kept the wreck from sinking deeper, and conserved it against corrosion. It also held some or much of the aviation fuel.

3. The entry hole may have been quite small, and may have been mistaken for a bomb crater, when some-one levelled the area to become farm land again.

4. The area was off-limits to civilians. The V-1 site must have made the surrounding area into a Sperrgebiet.

5. The Germans were thrown out of this area only three days after the crash of Jan Plesman. They were too busy saving themselves to care about this crash site. No German record has been found about this crash, and French archives hold nothing either.

Source for French archive material: Yves Le Maner, conversation dated 10/6/2006

The Germans did not even salvage the Messerschmitt wreck, fallen on 4/9/1943 a kilometer in front of their V-1 site under construction. The earth had swallowed the wreck.

6. Allied search parties may have been thrown off the right track by the less-than-accurate statement that he crashed Northeast of St. Omer, as stated by Plesman's two collegues on this mission. From the air, at 600 km/h, NE of St. Omer is how it may have looked. But it can't be true, if Plesman's aircraft dived in only seconds after being hit by Flak hidden in a Hazebrouck forest. Deviations of up to 50 kilometers are not uncommon in topological statements of combat aviators flying over enemy held territory.

7. The document in the RAF Casualty Files speaks of a wood 4 miles South of Hazebrouck. That may still prove to be accurate, see below. But the statement may also be less than accurate, and the Flak that shot Plesman may have been in this wood near Caneweele, situated 4 kilometer Westsouthwest of Hazebrouck city center. In fact this document from the Casualty Files forms the entire basis for the current search operation in Hazebrouck.

8. If the Flak in Caneweele wood shot Plesman, the he must have crashed within an estimated 2 kilometers from the Northern edge of the wood. That's sparsely populated farmland now, as it no doubt was during WW2 too.

9. If he crashed in this soil, and because no fire was seen after the crash, then there must be a lot of aviation fuel still present. That calls for a new instrument to assist the aviation archaeologist: a trained sniffer dog. The area is still too large to search with magnetometric equipment. The dog could search the field, without damage to the crops. That should convince the landowner to cooperate.

10. The Messerschmitt crash site yielded a lot of aviation fuel. That's poison to crops. This may well show up in aerial photographs taken today. As a circular spot of say six meters in diameter, with a slightly different colour. We need a small aircraft; even an ultralight could get this job done.

10. The exposition - more eyewitness accounts

9/6/2006

After seeing this forest, we go to the Ferdinand Buisson school, Rue Donckèle, Hazebrouck. Jean-Pierre Moille has arranged an exposition here, today and tomorrow only, of the Messerschmitt parts found. The main purpose is to flush out more eyewitnesses.


Exposition of the Bf-109 find in Hazebrouck. The main target is to flush out more eyewitnesses of the Plesman crash. The exposition draw an estimated 200 visitors, increasing the number of eyewitness accounts to over twenty. The key eyewitness, Mr. François Lesage, reported here too. Hazebrouck 060610 expo-4


Bf-109 engine parts. The force of the impact has ripped both cylinder banks from the engine block. Most parts of the aircraft seem to be there. A dozen personal documents were found too, all still well readible. Hazebrouck 060609 expo-4


Machine gun parts. Some of the metal is in first class condition, especially the steel parts that were blued or chrome plated. A loaded signal pistol has also been found. It discharged during the impact, blowing its barrel to bits. A shot from a signal shell delivers a first class igniter for aviation fuel. Still the wreck did not burn. The flare gun barrel blew, because it was obstructed by metal and earth. In a few milliseconds the aircraft transformed into a cubic meter of metal, with most of the aluminum aircraft skin shredded to fragments. Hazebrouck 060609 expo-1

Tableau with documents relating to the Plesman crash. All are of the 'we have no information' type. One is a nice find: Jan Plesman was awarded the Croix de Guerre avec Palme, posthumously, on 25/10/1948. In the left bottom corner a picture of the Memorial tablet at Orry-la-Ville, part of the document send by author to Air France-KLM on 26/6/2005. Hazebrouck 060609 expo-7


At the exposition, we meet Jean-Pierre Moille, interviewing elderly locals who have something to tell. He is a former Airforce pilot, now employed by Air France-KLM as the liaison with the French Ministry of Defence. He has been freed for the job of finding Jan Plesman. He has mobilized all help he could find. He is highly motivated, as witnessed by a portrait of Jan Plesman on his desk. Four more sites have been indicated by eyewitnesses, all very close to the Caneweele forest, but none of these coincide with events as we understand them. He explains that the next dig, as far as AF-KLM is concerned, shall be the last one. It is going to be now or never.

Jean-Pierre Moille, explaining matters to a school class. Not quite potential eyewitnesses of a 1944 crash, but education is part and parcel of historical research. Hazebrouck 060609 expo-6

One thing is worrying. Author's map of the Forêt de Nieppe search area is on display at the exposition. Jean-Pierre Moille asks who invented the Forêt de Nieppe hypothesis. Author is too amazed to follow-up with questions. Does he not understand the contents of the documents, including this map, submitted a year ago to Air France? Is English the problem? Our conversations are in French, because he prefers that. Anyway, we shall see how things develop.

Map 94. Crash positions around the Forêt de Nieppe according to eyewitnesses

The USAAF has taken an aerial photograph shortly after a bombardment in 1944. The period is 24/12/1943 to 10/5/1944. The picture is on display in Caneweele wood, also called Forêt des Huit Rues. Above it is matched to a map of the area. The blue dots mark alleged aircraft crash sites, as reported by eyewitnesses during the Hazebrouck exposition. These blue dots do not coincide enough with what we believe to know about the final moments of Jan Plesman. More information is needed, to direct the search with the magnetometer.

And then we meet Mr. François Lesage, aged 77, of nearby Bailleul. He came to the exposition to tell what he has seen, aged 15, near Caneweele. He saw a fighter aircraft being hit by Flak over Caneweele forest, turn down in a spiral to the left, with a white vapour trail behind it, and he heard and felt it crash into the ground. He was at a distance of about two kilometers, and he felt the ground tremble under his feet. He did not see the crash site; the area was Sperrgebiet. He estimates the time between the Flak hit and the crash at eight seconds. He describes that, two seconds after the hit, the aircraft turned over, flew back, and then dived to the ground. That's how it may have looked from his point of view. He describes that the Flak fired at the aircraft in a Norteasterly direction. All this coincides with what we believe to know about the final moments of Jan Plesman.

Later that evening, at a Hazebrouck bistrot, author sketches the statements of Mr. Lesage on a paper napkin, to make sure that everything is properly understood. Considering the estimated height, speed and heading of the aircraft, we can calculate an estimation of the crash site, West of the acre in which the Bf-109 has been found, North of the forest, and between 300 meters and about one kilometer from the edge of the forest.

François Lesage signing the napkin that we hope shall become a historical document. Hazebrouck 060609-5


The Lesage napkin. Hazebrouck 060609-6

11. Burial of the German pilot

Press release by the Volksbund Deutsche Kriegsgräberfürsorge:

Kassel, 7. Juli 2006

Deutscher Pilot des Zweiten Weltkrieges wird feierlich beigesetzt

11. Juli, ab 10.30 Uhr: Notre Dame de Lorette (Dep. Pas-de-Calais) und deutscher Soldatenfriedhof Bourdon (Dep. Somme)

Der im April in Frankreich mitsamt seiner Messerschmitt 109 geborgene deutsche Jagdflieger wird am kommenden Dienstag auf dem deutschen Soldatenfriedhof Bourdon (Dep. Somme) bestattet.

An der Gedenkstunde nehmen Vertreter des französischen Militärs, der deutschen Botschaft in Paris, deutsche und französische Kriegsveteranen des Zweiten Weltkrieges sowie Familienangehörige des aus Hildesheim stammenden Piloten teil.

Die Zeremonie beginnt um 10.30 Uhr in der Kapelle des französischen Nationalfriedhofes Notre Dame de Lorette, in der Nähe von Arras, wo die französischen Behörden die sterblichen Überreste des Piloten aufbewahren. Anschließend, gegen 11 Uhr, wird der Sarg zum deutschen Soldatenfriedhof Bourdon bei Amiens gebracht. Ankunft gegen 11.45 Uhr. Dort erhält der vor 63 Jahren abgestürzte Jagdflieger seine letzte Ruhestätte.

In Bourdon sind etwa 22 200 Gefallene des Zweiten Weltkrieges begraben. Es ist einer von über 200 Soldatenfriedhöfen, die der Volksbund Deutsche Kriegsgräberfürsorge in Frankreich pflegt.

Flugzeug und Pilot wurden im April bei Hazebrouck (Dep. Nord) entdeckt, als Beauftragte der Air France nach dem ebenfalls während des Krieges abgestürzten Sohn des Firmengründers suchten. Aus sechs Meter Tiefe bargen sie das Wrack und die Gebeine des Fliegers. Anhand der Erkennungsmarke konnte er rasch identifiziert werden.

Es handelt sich um den Unteroffizier Horst Seemann, geboren 1921 in Hildesheim. Nach dem Abitur wurde er zur Luftwaffe eingezogen und wurde zum Piloten ausgebildet. Anschließend meldete er sich freiwillig zu einem Einsatz an der niederländischen Küste. Am 4. September 1943 flog der 22-Jährige mit seinem Geschwader zu einem Einsatz nach England. Auf dem Rückflug stürzte er ab. Seither galt er als vermisst.

Volksbund Deutsche Kriegsgräberfürsorge e.V.

12. New actions – dogs, aircraft and a ground drill

1. Aerial photographs

In the conversations with Jean-Pierre Moille in Hazebrouck on 9/6/2006 it transpires that no effort has yet been given to get aerial photographs of the area, either of WW2 vintage or recent ones. Author urges that this should be done. It transpires that giant AF-KLM has freed one man for this job, and he is on his own. He could do with help. We agree that author shall write a request in English, again, to Keele University. And to the National Archives in Washington, where USAAF WW2 aerial photograhs are kept. But this time the request shall carry an AF-KLM letterhead, and it shall be signed by General René Perret of the French Air Force. This request, with maps of the search areas, was transmitted to AF-KLM on 12/6/2006. Photographs shall have to come from Keele and Washington. The Topografische Dienst in Emmen, NL, holds many copies of WW2 RAF aerial photographs, but only of those taken over Holland.

Source: Topografische Dienst, by phone, 26/6/2006.

Jean-Pierre Moille shall try to arrange a Gendarmerie helicopter, or perhaps a Rafale photoreconnaissance jet, for present-day photographs. We assume that several hundred liters of aviation fuel shall lead to crops that are coloured differently, either lighter than the surrounding area, or more likely darker.

3/7/2006

Jean-Pierre Moille reports that no word has been received yet from Keele University. On 4/7/2006 author phones up Keele, Reconnaissance Archive. The person processing the requests is instantly aware of the request from Air France. Staff is working on it, but these matters are laborious. Results to be expected next week.

2. The sniffer dog strategy

Author shall try to find a sniffer dog trained in aviation fuel. The Messerschmitt fuel kept by Mr. Claude Fleuri is going to be convenient to train a dog. Assuming that German and British World War 2 aviation fuels smell about the same. Where to find answers to a question such as this one?

13/6/2006

Author meets Martin Lipsius, who runs 'Het Twickelerveld' in Zandvoort, NL. His highly specialized company trains sniffer dogs. Training is for narcotics, explosives, and human corpses. He claims that no dog worldwide has been trained for aviation fuel. But he comes from the Dutch Airforce, and he is interested, and in fact challenged. He is willing to train two dogs, that are in their final stage of training, to the new substance. A 2 km square area search in crops means two dogs, because the work is hard on the dog. One dog works, the other rests. The area means two or three days. A magnetometer & laptop would be used at the same time, to record and investigate sites indicated by the dogs. However, it is imperative to get samples of the right substance. Anything less shall not do.

The expenses of working two dogs for three days in France, and hiring the ground radar, need to be paid. Estimated at a few thousand Euro's. Author feels that this contribution should come from Holland. He suggests to journalist and archaeologist Theo Toebosch that he can get the story, once Plesman has been found, for exclusive reporting in one of the Dutch national newspapers. The premisse is that finding Jan Plesman is frontpage news in The Netherlands. The condition is that the newspaper picks up the bill for the dogs. In that way the newspaper can rightfully claim to have contributed to the discovery, whilst we can get the job done. Theo Toebosch gives it a try, but finds NRC Handelsblad, the 'quality newspaper' in Holland, not interested. A year ago, author has found NRC Handelsblad to be not interested in the Rijklof van Goens story. 'Not invented here'. Author sends a similar proposal to the largest daily newspaper in Holland, 'De Telegraaf'. No response.

13/6/2006

The most unusual request for 1944 Spitfire fuel is forwarded to Mr. Gerrit Zwanenburg, former head of the Dutch aircraft salvage team, and to the current head, Captain Hans Spierings. Hans Spierings responds within hours. In his experience WW2 aircraft crash sites can contain vast, and highly dangerous, amounts of fuel. To his nose, the British fuel of WW2 smells as super grade petrol today. At the end of the War, the Germans used synthetic petrol for their aircraft. That could possibly be the case with the Hazebrouck Messerschmitt, and if true, than that would possibly be not the right substance to train the dogs.

Captain Hans Spierings retired early 2007.

14/6/2006

Word from Mr Gerrit Jan Zwanenburg. He has led the Royal Dutch Airforce salvage team for two decades. He tells that when the digging started, and you smelled fuel, then you knew you were at the right spot. German aircraft wrecks smelled very different from Allied ones. This was mostly because of the paint used by the Germans, as it was solved in fuel at the wreck site. He feels that training the dogs with German fuel would be a mistake. As it happens, he has kept a bottle filled with fuel found at a B-24 excavation site, IJsselmeer, NL, 1975. The Liberator had made an emergency landing on the IJsselmeer on 22/12/1943. When the aircraft was salvaged from the seabed, British 100 octane fuel was still in its tanks. Some of it is available for our purpose. He calls it coincidence, that he has kept the stuff for so many years. We see foresight in this. In any case, what seemed to be a perplexing puzzle has in fact been solved within 24 hours. This fuel did not meet with paint and earth; it still is a crystal clear fluid. Let's hope that this comes, to a dog's nose, close enough to the smell of wreck site fuel.

18/6/2006

Author meets Mr. Albert Plesman, his wife Tita, and their son Hans, in the Kurhaus, Scheveningen. Hans Plesman is travelling Europe with his family, and has invited his parents to the Kurhaus. After giving a briefing of the situation, author asks Albert Plesman to identify the top man of KLM in Holland, and to prepare access to him. The idea is that KLM could contribute to the effort by paying for the sniffer dogs. Then we would have the contribution from Holland, and matters would truly become an Air France-KLM effort. Albert Plesman identifies Mr. Peter Hartman, plaatsvervangend president direkteur, in the Amstelveen head office. He shall try to arrange access via Mr. Hartman's secretary. He tried, but did not succeed. Author is redirected by KLM to Mr. Peter Elbers, senior vice president of corporate communications.

18/6/2006

Author informs Jean-Pierre Moille by email of other tactics that could be used to find the Spitfire:

3. The no-dog sniffer strategy

These are the assumptions:

1. Jan Plesman's wreck is still embedded in British aviation fuel. Assuption generated by the findings and circumstances of the Bf-109 wreck close to where we believe that Jan Plesman has crashed.

2. There may be up to five aircraft buried in the Caneweele wood search area. But only one shall be British, and that shall be the aircraft of Jan Plesman.

3. The wreck site, being small on the surface, can be seen with the human eye in the following ways:

A. A circular depression in the terrain with a diameter of a few meters, and a depth of centimeters. See 'Crashs sur le Pas-de-Calais' by Hugues Chevalier, page 18, for a Spitfire crash site near Guemps, 8/1941, and how that's visible in 1986. Bottom line: such crash sites can still be visible, if you know what to look for.

B. A circular deviation of crop colour, size as above.

C. The presence of post stamp sized fragments of aluminium on the surface, coloured brown by the earth.

D. Any combination of A. to C.

E. These observations can be made, as the field shows rows of crops, with earth in between. In other words, the soil itself can be seen.

F. If the soil itself cannot be seen, as in grass land, then we can expect the depression to be a bit deeper, as that land has been ploughed less than farm land.

The top picture shows a Spitfire crash site, at nearby Guemps, August 1941. Aircraft and pilot were swallowed by the soil. We see a small entry crater, and scraps of wing aluminum at the surface. The bottom picture shows the same site in 1986. The ground has been levelled after the War, but over decades the soil sunk in, leaving a circular depression at the surface. Spitfire Mk. IIb Nr. P8541, flown by Sgt. J.C.G.C. Christie, 222 Sqn, died 12/8/1941, buried Terlincthun British Cemetery, grave 14/F/11. Source: Hugues Chevalier, 'Crashs sur le Pas-de-Calais', Lillers, 2006, pages 18, 41 Guemps crash 89-1941

4. If one or more of such sites are found, then it is entirely possible to drill a hole, diameter 8 cm, to a depth of 6 meters. I have located such a ground drill, that can be carried and operated by the muscle power of one man. The drill would produce samples of soil taken at various depths. If there is an aircraft wreck, and if there is aviation fuel, then we no longer need a dog's nose to find and to recognize the smell. Then we could use our own human nose. This ground sample taking is nondestructive to the farm land.

From these assumptions follow action plans:

4. Action plans

1. I offer you to scan the North of Caneweele wood search area, for potential crash sites, and I could take ground samples at potential sites, and 'see' via the samples produced by the ground drill if we find the smell of British aviation fuel. Sites then marked with a wooden stick, and via coordinates given by my mobile GPS instrument.

2. I offer you this at no charge to the AF budget for the operation. I'm motivated to get the job done, not to make money out of it.

3. For this I would need the following:

A. Your approval for this line of actions.

B. A map of the area, obtainable at the Hazebrouck Mairie, indicating what land is owned by which farmer.

C. A letter of recommendation from Mr. Paul Blondel, Maire de Hazebrouck, requesting farmers to allow their land to be entered and searched in the way described above.

D. A visit to the farmers involved, together with you, to get their approval for these actions. I could not do that alone; your command of the French language is needed for this.

E. Permission of Mr. Claude Fleuri, farmer living at the corner of the Rue de la Caneweele and Chemin du Prince, to park my camper there for the night. That would save me time & costs.

If this sound like a good idea to you, then please get information and cooperation from the Mairie in Hazebrouck. If we have that, then actions could take place in a few days. The search area would be as indicated in the map produced for the request for aerial photographs.

Scanning the area in this way might take a week, or 10 days. I am free enough to be able to make available that time.

If we would get aerial pictures, old and/or new ones, and if these would show spots that should be investigated, and if we would not yet have found the Spitfire, then we can still proceed with the technique described above. If even that would fail, than we can still engage trained sniffer dogs.

This strategy would allow us to proceed without money-matters being in the way, which is what I hate. It also allows us to proceed in a most independent way, which is the way to get anywhere in a short period of time. Being dependent of this or that institution, or Government agency, cannot be avoided altogether, but these dependencies do eat up a lot of time.

Please consider the above carefully. I'm aware that the argumentation above is a complex one. I'm also aware of the excitement that arises from the feeling that we are very close to the objective. Whilst in fact we should keep a cool head and take decisions that are as rational as we can make them. But I also believe that new and relevant ideas are present in the above:

- WW2 Spitfire fuel for smell reference,

- hand operated drill for ground sample taking for smell research,

- non-destructive area scan with human sensors,

- and some-one who offers to do this.

To me, it is entirely immaterial if such an approach would be novel to the field. If the job could not be done in the past 60 years, then obviously we need new ideas. That's what we are trying do do.

If you would agree, and if it would lead to the results that we both want, I shall have no problem whatsoever in sharing the credits with you. My strategy has a deeper layer. To me, finding Jan Plesman, the most well-known of all Dutch RAF aviators lost, is the obvious first step in trying to generate the backwind that I need to be able to do something about all the other Dutch RAF missing-in-action cases. That's the strategy, and there is no coincidence in that. Meanwhile, hard work, good ideas, good people, and luck, are needed.

21/6/2006

A company that specializes in geotechnical equipment has catalogued an extendable ground drill. With stainless steel elongation sections of one meter, a depth of six meters should be attainable, but the sales person wonders whether that can really be done. Obviously he has no experience with this, and the product is not in stock. The 6 meter drill arrangement would cost in the € 500,- area. And it would be heavy to carry into the field.

One hour later, author purchases a 1 meter ground drill at a Do It Yourself shop for € 11,- and reworks it with 2 meter sections of square aluminium tubing, and turning handles that can be repositioned along the drill shaft. A test drilling to a depth of 2,5 meters is made without any problem, and in minutes only, producing a nice line of consecutive ground samples each with a diameter of about 7,5 centimeters and a length of 30 cm. This drill shall cut through Hazebrouck soil without difficulties. If by chance a live 20mm cannon round down there at a fighter wreck site would be hit, explode, and destroy the drill bit, then a replacement shall cost € 11,-. The operator's head and body is to be kept clear of drill and handles. This tool may not last forever, but we feel that we are ready for the job.

23/6/2006

Meeting with Martin Lipsius of 'Het Twicklerveld' and Wim Dam, director of 'Cú Chulainn' international dog training center, Boekel, NL. Results:

1. The two square kilometer search area is too large for a full magnetrometric scan. With one scanner, having a 2 meter diameter cylindrical search area with a depth of 8 meters, about 8.000 square meters can be searched in a day, in a search pattern of lines spaced 2 meters. 2 km2, which is 2.000.000 m2, would require 250 days. Even the deployment of more search teams cannot provide a solution. At € 23,- per hour, for hiring only one scanner, costs would be prohibitive.

2. Scanning 2 km2 with trained dogs requires an estimated three days, two dogs, their two handlers, and one operator with a magnetometer. The magnetometer to be used only on the spot or spots indicated by the dogs.

3. This job is offered by 'Het Twicklerveld' and 'Cú Chulainn' for the fixed sum of € 4.000,-. That includes the training of two dogs, and all expenses for travel and lodgings. This is a most generous offer, well below the usual fee of € 83,20 per hour per dog trained on explosives, and about the same amount per hour for a suitable magnetometer with a trained operator. It is in fact about one third of what would normally be charged. We have been lucky enough to find Mr. Lipsius and Mr. Dam, both with a background in the Air Force, both directors of their own companies, and both challenged by this remarkable, and quite possibly unique, operation. Coming from the military, these men are not going to make noises should that extra day be needed.

Two dogs can be ready by mid August, if the green light for this operation is given soon.

5. Request to KLM

23/6/2006

A detailed request is send to Mr. Peter Elbers, Senior Vice President Corporate Communications of KLM. He is aware of what Air France is doing about the Jan Plesman case. He is presented with a summary of relevant data, and the quotation for the dog subproject. The request:

I would like to see that Air France receives a complete offer from The Netherlands, for the use of trained dogs. Also because The Netherlands as a nation have neglected the task of finding back this and the 89 other Dutch RAF aviators who were missing-in-action. I have prepared everything for that; now we need to get this financed. I believe that a cooperation of KLM, with partner Air France, to find back the Dutchman Jan Plesman, son of the KLM founder, in French soil, could be seen as most appropriate.

27/6/2006

RAF Air Historical Branch is asked for more data from Plesman's Casualty File. On 18/5/2004 RAF AHB reported:

Although these eye-witness accounts were very specific in the location of the crash of Spitfire MJ343, the Missing Research & Enquiry Service were unable to discover the whereabouts of the aircraft.

My request to RAF AHB:

The eye-witnesses of that time were very specific. Could you please inform me about the contents of these eye-witness reports, as that could prove vital to the current effort to find back F/Lt. Plesman. Especially as the AF-KLM company allows only one more excavation.

29/6/2006

Mrs. S.A. Dickinson of AHB5(RAF)2 answers:

I have re-checked the details contained in my letter to you dated 18 May 2004. The information I conveyed in that letter on the loss of F/Lt J L Plesman was from the Circumstantial Report from the Officer Commanding No. 322 (Dutch) Squadron, which I copied in full. The eye-witnesses were F/Lt Plesman's fellow squadron members who took part in the operation. These details were used by the MR&ES in their searches but despite being given a fairly precise location for his loss, it was not possible for the MR&ES to discover the whereabouts of F/Lt Plesman's aircraft nor were they able to find a grave for him.

I am sorry there is no additional information on the loss of F/Lt Plesman.

The circumstantial Report was given by Plesman's wingman F/Lt. W. de Wolff. The Casualty File for Jan Plesman does not hold MR&ES reports on interviews with local eyewitnesses. We had hoped that these would exist. We can hardly call F/Lt. De Wolff's statement 'Northeast' of St. Omer' a fairly precise one. France is a huge country. We are strenghtened in our belief that this statement is about 30 kilometers off the mark. The MR&ES team has searched in the wrong area.

29/6/2006

Mr. Gerrit Jan Zwanenburg hands over a small amount of 1943 B-24 Liberator fuel. Author asks for and gets a crash course in probing for aircraft wrecks. Mr. Zwanenburg used a pointed rod, either a one meter type, or the two meter foldable one. If a solid object was struck, then the 'bomblocator' would be employed. In his day the instrument had valves, not solid state miniature circuitry. The valve bomblocator was quite something to be carried in the field. But it worked, up to a depth of 8 meters. According to Capt. Hans Spierings, this instrument still functions, although more modern equipment is used nowadays. According to Mr. Zwanenburg, the probing stick never led to a detonation of a 20mm cannon shell, or worse. So it seems that the stick probing forces are too low to activate an impact fuze. With these two decades of field experience in mind, author can drill holes at assumed aircraft wreck sites in a much more relaxed way.

15/8/2006

After seven weeks, there is no word from KLM yet, other than that the request is under discussion. The two sniffer dogs could have been fully trained by now. In fact they are, but not to British WW2 aviation fuel. An opportunity has been missed. A new one may take many months to come.

30/12/2006

After several phone conversations with secretaries who were aware of the matter, but who could not report on the status of KLM decision making, author concludes that KLM has not responded to the request. Not a single word has been received.

13. Search area calculations

1. Flight data leading to possible impact areas

Below are drawings of the probable crash area, on the basis of the information we have. Drawings are exactly to scale. For unknown parameters author has made educated guesses, leading to a minimum and a maximum situation. The results are as the 'Lesage-napkin', but much more refined.

Figure 1. Vertical view, as from the air above Jan Plesman. (Fig 11 in manuscript)

The assumptions are:

a. The Flak was located at the Northern edge of a forest.

b. Flak was firing in the direction Norteast (Lesage).

c. The Spitfire flew at cruising speed, which is 500 km/h for this type at 3.000 ft.

d. The aircraft flew South to North (De Wolff)

e. Over a forest South of Hazebrouck (De Wolff)

f. Jan was hit, but continued in level flight for 2 seconds (Lesage)

g. The aircraft dived down in a left turn (De Wolff). The angle of the turn is unknown. I calculated with 20 to 70 degrees.

h. The range at which he was hit is unknown. I used a distance of about 1,5 km. The horizontal effective range of 2 cm Flak is 2,5 km. Later calculations with different ranges shall be made, and an explanation shall be given why author believes that it was 20mm Flak that shot Jan Plesman.

The left section of Fig. 1 shows a horizontal view, looking towards the East. The assumptions are:

i. The aircraft flew level at about 3.000 ft (De Wolff)

j. The aircraft dived down at an unknown angle. I have calculated for angles of max. 90 and min. 45 degrees.

These two angles lead to points of impact on the ground. At a 90 degrees dive, he crashed 1.440 meters from the Northern edge of the forest. At a 45 degrees dive, he crashed at 2.330 meters from the forest.

These results are transposed to the vertical view. That gives us a line of possible impact points, as a function of the dive down and turn left angles.

Figure 2. Jan Plesman impact area as a function of Flak firing distance. Plesman crash site calc fig 2.jpg (Figure 12 in manuscript)

Fig. 2 shows results from Fig. 1, but now as a function of the firing distance. I estimated this to be between 500 and 2.500 meters, the latter the max. effective range of the 20mm Flakvierling. This produces an impact site area of 1 by 2 kilometers.

At this stage, the geometrical model was redesigned into a mathematical one, made in Excel, that allows all parameters to be adjusted. The parameters to be chosen as a bandwidth of educated guesses, pending harder data. A dive speed higher than the level cruising speed can now be set too. A firing direction function was introduced too. Mr. Lesage said Norteast. Calculations have been made for Northnortheast to Eastnortheast.

So, in Graph 4 below, we have accounted for all available data, plus or minus ranges that come from educated guesses for parameters for which we have no hard data. That gives us a crash area that stretches from 590 to 3.400 meters North of the Flak position, and 1.250 meters West and 2.270 meters East of that position. That's a large area.

As Flak may have been positioned anywhere, this search area needs to be projected along the Northern edge of the Forêt de Nieppe. As F/Lt. W. de Wolff saw St. Omer in the distance, I assume that the 3 aircraft flew over the Western part of the Forêt de Nieppe. Otherwise he would have seen and mentioned Hazebrouck as the crash area. But we cannot exclude that they actually flew over the Bois des Huit Rues. That would lead to a second search area of the same shape, now projected along the Northern edge of the Bois des Huit Rues.

Furthermore, the Flak may have been positioned deeper in the Forêt de Nieppe, at the Southern edge of an open spot. In that case, the search area shape would remain the same, but the position would be more to the South. I did not put that unknown factor in these drawings too.

There is no way that Jan, with the data we have, could have crashed Northeast of St. Omer. F/Lt. De Wolff corrected that statement later, as evidenced by F/Lt. Van Eendenburg's log book, but the statement remained in the 322 Sqn Operations Record Book, and in De Wolff's Circumstantial Report. Both of these reports no doubt produced on 1/9/1944, during the mission debriefing.

Graph 5jp. Jan Plesman impact area as a function of flight and Flak parameters Plesman crash site calc fig 4.jpg

In the above it has been stated that the practical horizontal range of 20mm Flak 38 is reported as about 2.500 meters. Therefore there would be no need to search far beyond that range. But the HE projectiles fired by this weapon with a muzzle velocity of 900 m/s, travelled a max. horizontal distance of 4.800 meters. At a range of 3.000 meters, the shells would still travel at over 350 meters per second. That's quite enough to detonate the shell's impact fuze, if it would strike a hard target. In other words, at this stage we cannot exclude that Plesman was hit at longer range than 2.500 meters. The search area depicted above, calculated for a max. range of 2.500 meters, may not yet be large enough. We need to study Flak ballistics closer, to come to grips with these uncertainties. As done in the next chapter.

2. Flak data leading to possible firing ranges

The circumstantial report from F/Lt. W. de Wolff mentioned smoke and flames pouring out of the aircraft when on the dive down. That would indicate that Plesman's Spitfire was not only hit in the tail, but also in the cooling system and/or, more likely, the fuel system. We assume that the Spitfire was hit by 20 or 37 mm cannon shells, not 88 or 105 mm ones. More probably a burst from a 20 mm Flakvierling, mounted perhaps on an Opel truck. The practical ranges of this weapon were about 2 km vertical, 2,5 km horizontal. It fired a hefty 1.800 rounds per minute.

A 20mm Flakvierling 38 mounted on a halftrack. Source: panzerkeil.dre.hu/.../ sdkfz7/gal/gal_sdkfz7.htm Flakvierling 5


Another of the several types of mobile 20mm Flakvierlinge. This picture expresses the situation during the German retreat from Northern France in September 1944. The equipment resembled a moving forest. The weapon is deployed next to a wood, giving concealment on one side whilst retaining a field of fire on the other. Source: www.ww2technik.de/ dFlak_leicht.htm Flakvierling 5


Hitlerjugend, boys of sixteen, 'manning' a VierlingFlak at the Reichsparteigelände, Nürnberg, in the summer of 1944. Source: Nürnberg Dokumentations-Zentrum

The Spitfire's overall length was 9 meters. The distance between tail and the fuel system area is about 7 meters. This data can be matched with Flak data, to see under which circumstances two hits could be obtained.

The heavy Flak calibers fired shells with time fuzes to a precalculated point in the sky. The small calibers proceeded in a different way. Tracer projectiles with impact fuzes were used to sweep the aim towards the target. A hit was needed for a shell to detonate. Firing was done whilst elevating and traversing the guns. Aim would be taken with a lead that depended upon the target's distance and speed. For the 20mm Flak 38, the lead distance would be 550 meters when firing at the maximum practical horizontal range of 2.500 meters, at an aircraft flying with 500 km/h. High Explosive projectiles, leaving the muzzle at 900 meters per second, would need 4 seconds to reach the target at 2.500 meters, due to the speed decrease as a result of air friction. In four seconds the target would travel 556 meters, hence that lead distance.

The maximum firing rate was max. 450 rounds per minute, or 7,5 rounds per second. In Graph 5 below, a burst to max. practical range is depicted versus the time of projectile flight. The pink line shows the aim deflection needed at ranges up to 2.500 meters, when firing at Plesman's Spitfire.

Graph 6jp. Single 20mm Flak gun deflection firing pattern Plesman Graph 6

Depending on the target's speed and distance, aim would be taken well ahead of the target's flight path. If done in a perfect way, then the first shells would hit the target. But perfection is unthinkable in a War situation, where everything is moving very fast, and in four dimensions. The aim would be off the mark, and typically the tracer rounds would be behind the target. In order to acquire the target, the gun had to traverse, or rotate in the horizontal plane, and do so with a relative speed higher than that of the target, in order for the projectiles to catch up. The same would have to be done in the vertical plane, meaning that the gun barrel had to be elevated. But as Plesman was flying level, we can focus on the horizontal movements.

In Graph 6 below, we see projectile flight lines, fired from a single 20mm Flak gun, rotating or sweeping at a speed of 600 km/h, as compared to the Spitfire. The horizontal distance between the projectiles is a function of the sweep speed. Higher sweep speeds lead to greater inter-projectile distances. At a 600 km/h sweep speed, the target had to be at a distance of max. 804 meters, if two projectiles were to hit 7 meters apart. At greater ranges, a single gun could not achieve two hits at this swing speed.

Graph 7jp. Single 20mm Flak gun sweep speed versus 7 meter envelope line

For the 20mm Vierling, things are more complicated. If all four guns would fire at exactly the same moments, then the sweep spread would be almost the same as that of a single gun. But guns were not perfectly identical, and neither were the rounds. A certain asynchronicity was in fact desirable, as that led to smaller inter-round distances when sweeping towards the target. We call that the synchronisation factor S, in which S has values between 1 and 4. 1 would be perfect synchronisation, all guns firing all rounds at exactly the same time intervals. 4 would be perfect asynchronicity, guns firing at successive intervals of exactly 1/4th of the firing rate. Reality shall have been somewhere in between these values. In Graph 7 below we have calculated with a synchronisation factor of 2,5. This results in a 7 meter envelope line of the Flakvierling at the range of 2.010 meters. In other words, a Flakvierling, sweeping at 600 km/h, with a synchronisation factor of 2,5, would be capable of achieving two hits on Plesman's Spitfire at ranges of up to 2.010 meters. That makes the Flakvierling, if guns are sufficiently out of sync, the much more lethal weapon than a single 20mm Flak gun.

Graph 8jp. Vierling sweep spread & 7 meter envelope line Plkesman Graph 8

In Graph 8 above we have enlarged a section of this firing pattern, and inserted a Spitfire profile drawn to scale. Under the conditions mentioned above, the Flakvierling could achieve two hits at ranges up to about 2.000 meters.

Graph 9jp. 20mm Vierling Flak hitting a Spitfire with two rounds Plesman Graph 9

All graphs above were calculated for a Flak sweep speed of 600 km/h. However, we do not know the sweep speed that was used when this Flak fired at Jan Plesman. In the table below we give the results of calculations with sweep speeds of 550 to 850 km/h.

Table 13. Max. ranges for 7 meter envelope line of 20mm Flak versus sweep speed Plesman

The conclusion is that a single 20mm Flak gun could, at these sweep speeds, achieve two hits only at firing ranges of max. 877 to 567 meters, which is very short in AA Warfare. On the other hand, the Flakvierling could achieve two hits at ranges of max. 2.192 to 1.419 meters. As a perfect gun asynchronicity, S factor = 4, is unlikely to have occurred, we conclude that Jan Plesman most likely has been hit by a Flakvierling firing at a range of up to 2.200 meters. And that would not substantially reduce the search area calculated in the previous chapter.

All this mathematical magic could be reduced to a much smaller search area, if we would know the exact position of the Flak, or better the exact position of Jan when he was hit. But we don't.

14. Keeping the focus - two possible crash areas

In the Hazebrouck exposition we noticed the red-faced tension of the hunt, author no doubt included. Finding the German aircraft has demonstrated that results can be achieved, goals reached. Everybody wanted to help, wanted to be in on it. That's excellent, but we need to keep the head cool.

The eyewitnesses have all pointed towards the Bois des Huit Rues area. There is a V-1 launch site here, called Nr. 623 by the Germans. Laurent Bailleul has studied the V-1 sites in Northern France, and has published 'Les sites V-1 en Flandres et en Artois', Hazebrouck, 11/2000. He uses the name of the nearby town of Morbeque as the name for site Nr. 623. In his book we learn that site 623 received no less than fifteen aerial attacks by bomber aircraft, the first one on 24/12/1943 and the final one on 10/5/1944. Bombs were scattered over a wide area, leading to the loss of civilian life too. Site 623 was hit sufficiently to discourage the Germans to complete its construction. They stopped the construction work at the end of February 1944.

Source: Laurent Bailleul, 'Les sites V-1 en Flandres et en Artois', Hazebrouck, 11/2000

We can no longer be confident that the Flak that shot Jan Plesman on 1/9/1944 was positioned here.

The Flak that shot Plesman may still have been located in the forest 4 miles South of Hazebrouck, as reported by F/Lt. W. de Wolff. Mobile 20, 37 and 88mm Flak guns may have been positioned anywhere, and be repositioned at will within hours, and no record was kept of such movements. Early September 1944 The Germans were on the retreat. By day, equipment would be concealed in woods, if at all possible. Flak guns would be positioned at the edge of woods, so that the guns would be semi-concealed, but still have a field of fire. Laurent Bailleul has spoken with many eyewitnesses who have seen Flak near the Forêt de Nieppe, but he cannot give positions and dates.

Source: Laurent Bailleul, email 28/6/2006

At the Northern edges of the woods, the Flak would have a field of fire into the main direction from which the Germans expected Allied UK based aircraft to come.

Flak was indeed present here, indicated on the map below. This fixed Flak position was there to defend two large bunkers, a 'Feldspeicher', that were supposed to hold supplies for the envisaged V-2 launch site at Wizernes, now the La Coupole museum. No eyewitnesses came forward who reported a crash in the area North of the Forêt de Nieppe, many believe to have seen crashes around the Caneweele forest. So it stands to reason that Jean-Pierre Moille decided to dig in this area. Meanwhile, a propellor has been found directly North of the Forêt de Nieppe. The forest itself may offer an explanation why the people have not seen any crash site, as explained before. All this goes to say that we need aerial photographs of this area too.

The eyewitnesses who have pointed to the Bf-109 wreck site area, erred in their recollection of the year. Uffz. Horst Seemann fell 4/9/1943, almost a year ahead of F/Lt. Jan Plesman. The Germans did not bother to salvage this wreck, laying only a kilometer in front of an active V-1 construction site. That's unusual in 1943. The Germans may not have seen the wreck site. The small crater may have escaped notice in the crops. Aerial photographs taken during or after a bombardment of the Bois des Huit Rues may reveal this crater. If true, then that would be a reference when scanning Wartime aerial photographs for the crash site of Jan Plesman.

There is one more scrap of information that surfaced only recently. In his log book, F/Lt. Kees van Eendenburg noted: "F/Lt. Plesman, hit by Flak 5 min. after been hit myself, part of his tail shot away. Spun in from 2000' and explodes in fire on the ground Nr. Hazebrouck, presumed killed".

Source: Hugues Chevalier, page 236


LCM van Eendenburg Source SLH

F/Lt. Van Eendenburg wrote this after 11/9/1944, when he had returned to England. He cannot have seen the Plesman crash himself, as he had to make an emergency landing East of Mametz directly after being hit, and as he was leading another 322 Sqn section. His statements must come from information provided by Plesman's wingman. Van Eendenburg noted 1/10/1944 as the date, which is an error. He also wrote down the altitude as 2000 rather than 3000 ft. If his notes are otherwise true and accurate, we learn the following:

1. A confirmation of Hazebrouck as the crash area. As the statement can only have come from Plesman's wingmen, it means that, two weeks after the event, he or they have reconsidered the original 'NE of St. Omer' statement. Let us try to understand that. The wingmen were heading NE of St. Omer, and they could probably see St. Omer on this clear day. We assume that F/Lt. De Wolff looked back, saw the Plesman crash site, and saw St. Omer in the distance. He did not, during the debriefing directly after the mission, report about Hazebrouck as the crash area, although he did report about a forest 4 miles South of Hazebrouck as the Flak position. He saw the forest on the way in. We assume that F/Lt. De Wolff was flying to the right of Plesman, and looked to the left, seeing the crash site as well as St. Omer in the distance. Later, when consulting a map, he saw that 'near Hazebrouck' would be more accurate, and so it was written down by F/Lt. Van Eendenburg. In the 322 Sqn ORB and the Circumstantial Report the statement 'NE of St. Omer' persisted. This course of events would place the line of flight more likely over the West section of the Forêt de Nieppe. The search area indicated in the first map above, needs to be extended to the West by about 2 kilometers. As done below.

2. Plesman was seen to crash into the ground, meaning that he probably did not crash in a wood.

3. The aircraft was seen to explode on the ground in fire.

The last statement means, if true, that we no longer have a crash situation identical to that of the Bf-109 found near the Bois des Huit Rues. There may not be much fuel left at the Plesman crash site. We need to rethink.

F/Lt. Van Eendenburg heard and wrote down that there was an explosion in fire on the ground. That would mean that the aviation fuel sniffer strategy may not work. The wreck still is likely to be there, somewhere, engine and other main parts buried several meters below ground level. As Flak may have been positioned anywhere during the German retreat, and as there are probably more aircraft wrecks still undiscovered in this area, we need an additional method to distinguish between German and Allied wrecks, without a full excavation.

Perhaps as follows. Ammunition found at a wreck site would clearly distinguish between a German and an Allied aircraft. The Allied fighters had their armament mounted in the wings. A fighter aircraft that dives in almost vertically would have its wings torn off. Wing parts would remain at the surface. Heavy components, such as the guns and cannon, would go deeper than lighter material, such as the .50 machine gun cartridges of a Spitfite Mk. LF IXE. We assume that the drum magazine of the 20mm cannon would go down as deep as the cannon itself. We assume that the belt feed of the .50 machine guns would disintegrate, and that therefore .50 ammo can be present higher up in the ground. We need ground sample taking equipment, that could bring up .50 rounds. In other words, we need a ground drill with a drill head diameter large enough to catch .50 cartridges, that have an overall length of about 11 centimeters. Finding a single .50 projectile, that was not fired through a barrel, but that 'cooked off' in the wreck on fire, would already distinguish an Allied wreck from a German one.

The information in this subchapter was transmitted to Jean-Pierre Moille on 1/7/2006. He did not respond.

Map 95. Map summing up the Plesman search grids Plesman crash site calc fig 5

The search effort has been concentrated on the Forêt des Huit Rues area, because of the eyewitness reports. No-one came forward with information about an aircraft crash in the La Motte aux Bois or Forêt de Nieppe area. From the statements of F/Lt. W. de Wolff, Plesman's wingman, we believe that the search should include the Forêt de Nieppe area, and the Bois d'Amont area in particular. The assumption in the graph above is that the Flak was positioned along the Northern edge of the forest. The search grids calculated earlier are projected along the assumed Flak position line, leading to a sum of search grids, in yellow. This has been repeated for the Forêt des Huit Rues area. Now we need to compare these areas with aerial photographs taken shortly after 1/9/1944.

15. The Benedictine Way

27/6/2005

Joss Leclercq is the aviation archaeology researcher in Northern France with possibly the most profound knowledge of WW2 aircraft crashes in the St. Omer area. On a web forum he stated the following:

L'autre est Jan Plesman, toujours porté disparu, qui serait tombé dans le secteur de St Omer, mais sans réelle précision. Régulièrement des demandes sont publiées dans la presse locale, la dernière il y a quelques jours à peine. Le père de Plesman était l'un des fondateurs de la KLM et depuis le rapprochement Air-France/KLM, certains à Air France essaient d'en savoir plus. Mais seul un travail de bénédictin sur le terrain et auprès de certaines services d'archives pourrait apporter des éléments nouveaux et tangibles. Mais ceux qui demandent espèrent trouver des "bonnes poires" qui feront le travail pour eux, et ensuite ils tireront les marrons du feu.

Source: Joss Leclercq on www.aeroforums.fr dd. 27/6/2005

With this he expressed two opinions:

1. Finding Jan Plesman requires a munk's work in both the archives and the fields.

2. There are those who try to run off with the results of such hard work done by others.

We are in agreement with both opinions. The second one demonstrates frustration coming from bad experiences. Author has had his share of all that. But that is part & parcel of the life of the munk.

18/8/2006

It has been seven weeks since the last feedback from Jean-Pierre Moille. RAF aerial photographs, if these exist, should have been received by him weeks ago. Present-day aerial photographs should have been made by now. But nothing seems to happen. In the past seven weeks, author has send him eight more emails containing new data. No response. We had hoped for more acting power, sharper case management and better communicative abilities, from the huge Air France-KLM company. Meaningful action could have been taken two months ago. Now the crops are too high; we need to wait until after the harvest season.

Unfortunately, the Order of the Benedictines cannot resolve these cases entirely within themselves, as authorities have made laws to limit their actions.

12/09/2006

Author is travelling in France for the xth time, for a >4.000 km trip, from Cherbourg, Normandie, to Bayonne, in the Pyrenees, trying to find more data about the Dutch RAF aviators who were lost here. One of the ideas is to pay Jean-Pierre Moille a surprise visit at his Air France Headquarters in Paris. The biz card has Rue de Paris 45, Roissy, as the address. That leads to nothing. It has to be Rue de Paris, Roissypole, on the huge terrain of the Charles de Gaulle Airport. As everybody knows, except the visitor from abroad. The security staff at one of the entrances, being very suspicious of the dog in my camper, calls Jean-Pierre, and he is in his office. Could I call back in one hour, meaning after office hours? So that's done, camper parked on the Place de Madrid, around the corner of the AF-headquarters. We expect to be invited to JP's office, or to a restaurant in the area, to discuss proceedings & progress. This does not happen. JP explains on the phone in French that he has been so very very busy. The 'Jan Plesman dossier' had to wait. He has not even evaluated the data generated by the Hazebrouck eyewitness interviews collected early this year. Aerial photographs have been received, but these did not reveil 'grand chose'. We are not looking for 'grand chose', we are looking for tiny circles that could indicate the crater of a Spitfire crash. A copy of these pics could help, but I am not getting that. I cannot even, during this phone conversation, get it confirmed that these are the RAF aerial photographs requested. JP announces that he plans to take up again 'ce dossier' next month. We deviated about 200 km from our travel schedule, through horrible Paris rush hour traffic, to learn that nothing has happened during the past 3 months. It is clear why JP does not want to extend the famous 'Acceuil Français' to travellers coming from afar and now parked at his doorstep: he has nothing to report. We cannot be impressed by any of this in any way. The mission to 'find Jan' has become merely one of the dossiers. I shall be patient for another month or so, and then, if need be, develop my own actions to get on with this 'dossier'.

16. No more patience

1/12/2006

That October meeting with Air France did not materialize. No word whatsoever came. Author shall wait for the winter to pass. Then it is time to engage the Major of Hazebrouck, who shall be requested to pave the way for permissions from local farmers to enter their grounds. Camper, WW2 British aviation fuel sample & deep ground drill are ready; now I need those aerial photographs. Have asked Jean-Pierre Moille today, to send copies. He could have done that ages ago. He really should have.

No answer. The request is repeated on 6/12/2006. No answer. Air France is a write-off.

Keele University has a website on air since 2004, promising access to RAF aerial photographs, the 'Aerial Reconnaissance Archive'. But there is no access. Photographs go to commercial parties only, until such times that Keele has sorted the problem of access to the more than 5 million photographs. Author, being a private individual, is not getting anything out of this archive. Mickaël Simon points to the Institute Géographique Nationale in Paris, www.ign.fr. Aerial photographs of many parts of the country are available, taken in many different years. The earliest series dates back to 1947. Several 1947 photographs are available of areas that are within the calculated crash areas. Copies are € 20,- each. They are easily ordered online, if one has the right credit card. Three photographs are ordered, of the main areas of interest.

December 2006

The Dutch journalist Theo Toebosch brings author into contact with the Groundtracer company, residing in Apeldoorn, The Netherlands. This two man company has developed ground surveying equipment, that combines ground radar with measurements of the – changes in – electric field of the ground. The scan rate is 25 kiloHerz, and that translates to an area search capability of about 2 meters wide, with a forward speed of about 25 kilometers per hour, depending upon the terrain. That's a major improvement in speed over the conventional magnetometer. The antenna is in fact mounted under a quad motorcycle, for the envisaged operation. The instrument can 'see' to a depth of about 8 meters, also in clay. A laptop doubles as datalogger and data analysis & presentation instrument.

The company was founded in 2004 by Dick van der Roest and Marten van der Rijst. Both studied geophysics. After only two years of operations as a company, their equipment is sought globally. A project was done for the US Navy, mapping the bottom of Philadelphia Naval harbour. The USN did not have the right tools for the job. Groundtracer BV mapped the 50 hectares of the harbour in two days only.

Succes has been such, that they permit themselves one hobby project a year, in the archaeological sphere. The search for Jan Plesman qualifies. The Groundtracer company has offered its help, at no cost. Provided that the aerial photographs shall enable us to limit the search area, that is still far too large. That shall be the basis for the technical side of the plan of operations.

With this splendid offer from Groundtracer BV, we are almost ready for the design of an action plan. We also need some-one from the area, who has thourough knowledge of the subject-matter, and of the French way of doing things. The action shall be on the soil of France, meaning that French law shall apply. We need to know which permits are required, where to apply for these, and which other official parties need to be notified, or involved. Furthermore, we need some-one who is a native French speaker, when matters need to be discussed with local authorities and farmers. We have asked Jocelyn Leclercq, after it became evident that he is very capable and knowledgeable in the field of WW2 aviation archaeology in that part of France. Furthermore, he feels strongly that things have to be done in the right, meaning legal, way. We would not have it any other way. Finally, Joss' English is excellent. Joss was reluctant to cooperate, being wary of illegal digging for aircraft that has taken place in the area, but he agreed. He shall share full credits for any results achieved by this team, that looks a really good and strong one. No more waiting for months for responses from parties that cannot communicate, and that conveniently forget about the origin of all this, when it comes to publications. Author claims to be the origin for a search for Jan Plesman, and in the Hazebrouck rather than in the St. Omer area. Author happily left it to the French to do the work on their own ground, but that did not unfold in a succesful way. The time has come to take back the initiative.

The action plan shall be produced by author. It shall include safety aspects, and proceedings if remains are found that cannot be identified straight away. This action plan shall be discussed with, and finally approved by, all actors involved. We shall have to write our own JPAC type of textbook. We hope to get input from the Dutch Aircraft Salvage team (DIB) for this textbook. The Dutch shall not operate their team outside of The Netherlands. But support in the know-how sphere might be available.

6/1/2007

Aerial photographs are received from the Institute Géographique Nationale in Paris. Photos taken in 1947. There is a lot of information in these.

IGN 157 Aerial 1944 and 1947 Craters

IGN aerial photograph, taken in 1947, and one of three of the Hazebrouck area in which we believe that Jan Plesman crashed. The forest at the center left is the Forêt des Huit Rues. At the right top is the Western edge of Hazebrouck, with the railway going West. Superimposed in the yellow square is a USAAF 1944 picture, showing a carpet of bomb craters, here indicated with green dots. These craters match many craters in the 1947 picture, here indicated in purple, and that proves that the structures seen in the 1947 picture are indeed bomb craters. Many have been shovelled level by 1947, but dozens remain. The site at which Horst Seemann and his Bf-109 were found, is at the blue dot. There is no crater visible here in the 1947 picture. We assume that the aircraft crash crater was believed to be a bomb crater, and shovelled level so that the farmer could use his land again. We assume that this may also have happened with the crater of the Jan Plesman crash. One of these craters matches with an eyewitness report.

The other two aerial photographs show a dozen of such craters. Now we need to investigate all these potential crash sites, to see what can still be seen, and that hopefully includes scraps of aircraft aluminium on the surface. That should lead to a workable plan of action for the ground radar.

12/1/2007

A letter is send to Mr Paul Blondel, Mayor of Hazebrouck, requesting a letter of recommendation, that should help during the initial ground survey. As perhaps 40 land owners are involved, it would be a long process to get written permissions from all of them. The initial optical survey should bring that number down to perhaps five. We announce to the Mayor that he shall receive a full plan of action, for his approval, after this initial ground survey has enabled us to write that plan. The letter is translated into French by Joss Leclercq.

8/2/2007

Author receives a call from Colonel P.E. Mulder, military attaché at the Dutch Embassy in Paris. Mr. Paul Blondel has asked him to advise regarding my request. That's a lucky strike. Up to two years ago, before he became attaché in Paris, Col. Paul Mulder commanded Leeuwarden Airfore Base, home of 322 Squadron. He also held the position of 322 Squadron Commander for some of that time. He is interested in finding back Jan Plesman. He shall advise the Mayor of Hazebrouck in a positive way, he wishes to hear of developments, and he promises to see to a funeral with full military honour, if we find Jan Plesman.

We now have tailwind:

17. Potential grave robbers around

31/12/2006

Joss Leclercq reports that a WW2 fighter aircraft has been excavated illegally, in October 2006, near the village of Sercus. The offence was committed by people from England. The wreck was said to be a Messerschmitt Bf-109. The parts were taken to England. He believes that the French Gendarmerie is not very interested in such a case. He also believes that the British police shall not be interested.

We shall see about all that. Sercus is very close to the calculated Jan Plesman crash area. For many reasons, author cannot let this offence pass by. A criminal investigation has to be added to the search for Jan Plesman.

13/1/2007

After some more research by Joss Leclercq & author, the following crime report was filed with the Kent County Constabulary in Maidstone, under the assumption that the wreck was brought in at Dover, meaning that in Dover the offence started to fall under British law.

This is to report an offence against the Dealing in Cultural Objects (Offences) Act 2003. The offence took place in October 2006, when Englishmen dug up a World War 2 fighter aircraft near the village of Sercus, Nord, France, and removed the wreck to England. This excavation was entirely unauthorized, and therefore contrary to French law. Taking the parts to England, knowingly without proper authorization, is an offence against the forementioned British law. Trading in these parts may have added to this offence.

Reasons for this report

This report is given to you, as the matter is not merely about petty smugglers dealing in WW2 metal:

1. I have reasons to believe that the remains of the pilot may well have been in the wreck. If true, then this pilot, who was missing, now has his remains stolen, and quite possibly thrown away.

2. Quite close to the village of Sercus, a German fighter aircraft has been found and was excavated, in March 2006, by a team led by Air France, everything done by the book. The remains of the German pilot were present in the wreck, were identified, and were reburied on a German War cemetery in France.

3. The excavation of the German aircraft is part of a search for a Royal Air Force Spitfire, that vanished with its pilot in this area. The aircraft was flown by F/Lt. Jan Plesman, Dutch, son of KLM founder Albert Plesman. Air France and KLM merged a few years ago. This search has been initiated by me, since 2003.

4. The aircraft dug up and removed illegally in Sercus is said to be a German Messerschmitt Bf-109 fighter, but, without sufficient evidence, this may also have been a Spitfire. Wrecks of these two aircraft types look quite similar, after a dive into the ground. Only specialists would be able to identify the wreck. The local farmer is not a specialist, and after he had seen the wreck, it was smuggled out of sight.

5. Therefore, in Sercus the aircraft and body of F/Lt. Jan Plesman may have been stolen, and smuggled into the UK.

6. In the sphere of aviation enthousiasts in England, no report about this excavation has surfaced. We have to assume that the wreck parts disappeared into an illegal circuit of collectors, who financed this excavation.

7. We have to assume that this is not an isolated case. This stealing of historical evidence is becoming recognized as a problem. In May 2007 a conference about the subject shall be held in Wizernes, Nord, France. The conference is aimed at governmental parties. Staff of the Air Historical Branch of the Royal Air Force is to be present also.

8. The brother of F/Lt. Jan Plesman is still alive. He is well aware of the search for his brother, and he fully supports it. He is available, if it would need to come to a DNA comparison.

Offence data

As far as available to me at this point.

The farmer involved is Mr. Francis Deram, of Blaringhem, Nord, France. He was led to believe by a person from England, that the aircraft was Crown property. The statement would be true in England, but not for a Messerschmitt in France. The Mayor of Sercus declared on 12/1/2007 that his permission for this excavation had not been requested. A licence for this excavation was not requested from the authority on archaeology in France. In other words, the accused knew perfectly well that their actions were illegal. We believe that a Mr. Andy S. may have been involved. Details left out pending a police investigation.

The farmer confirmed by phone on 13/1/2007 that the dig was carried out in one of his fields. About 10 years ago, while he was ploughing, some aircraft parts were caught in the plough and brought to the surface.

A group of British people came, he doesn't know their names. They were equipped with metal detectors and the like. They hired a mechanical digger (Clerbout in Boeseghem, who is the digger driver they always hire) and found an engine. The farmer doesn't know anything, he was told it was a Messerschmitt. He couldn't tell more. But he would probably recognize the faces.

The engine would be the main part that can be found at the crash site of a WW2 fighter aircraft. The farmer's observation does not necessarily mean that only the engine was found. As explained earlier, a WW2 single engine fighter aircraft compacts to about the size of the engine during a dive into the ground.

In any case, historical evidence has been removed illegally, quite possibly including the remains of the pilot, imported illegally into the UK, and hidden from public sight. I hope that this presents sufficient evidence for you to start an investigation.

Requests

I request you to investigate this offence, with the purpose of bringing the offenders to justice, and most of all of retrieving the stolen wreck parts, and possibly the remains of the aviator involved, so that the designated authorities can investigate the wreck, and report their findings.

I also request you to inform me, as far as possible, about your actions in this matter, and their results.

I urge you to take this matter very seriously. The name of Jan Plesman sees to it that the public shall be looking over our shoulders.

This report was filed via the UK Police crime reporting website, that was quite inadequate for this unusual report coming from abroad. However, within half an hour after filing, Mr. Simon Davis of the Kent Police called, wanting to hear more detail. He shall study the case, and report back what the British Police can and shall do. So at least the matter is receiving serious attention.

It strikes me that the attention of these perpetrators may have been attracted to the Hazebrouck area via the June 2006 exposition of the Bf-109 excavated by Air France. At this exhibition a map was shown in plain sight, indicating crash site locations as reported by eyewitnesses. These were drawn on the map by Jean-Pierre Moille during his interviews with the eyewitnesses. This procedure was well intended, but must now be condemmed as critically naïve. We do not live in a honest world.

How can this illegal dig have happened without some-one having done something about it? As follows:

1. The farmer/land owner was told that the aviator was a family member of one of this excavation party. And he was told that the wreck is Crown property. The farmer was happy to cooperate with this action, that he believed to be a honest and indeed moral one. He had no idea of the rules that apply, and he did not think to ask some-one.

2. Such an excavation, when done rapidly rather than carefully, takes two days. A Spitfire or a Bf-109 transforms into a cubic metre of metal, during a dive into this ground. That lump of metal can be spirited away by a van.

3. France is a vast country. Agricultural machines are active everywhere. So few people may have taken notice.

But the matter has been seen, and that's how we got our information. Author does not care where the metal goes, even if it would be Jan Plesman's Spitfire, as long as the matter is properly recorded, in records made accessible to the public. But human remains can go one way only: to the family of the casualty.

Many WW2 aircraft excavations are described on a website called 'Aviation Archaeology', written by Mr. Simon Parry, www.redkitebooks.co.uk. Many of these excavations are about aircraft, from which the casualties have been removed for proper burial shortly after the crash. Finding back the remaining metal, and reporting upon that in the public domain, can be a great hobby, and be justified perfectly well, but smuggling is against the law. We identified 11 excavations in Nortern France, done by the group of Mr. Andy S. from 2004 up to and including 2006, with no clear mention that the designated authorities had been involved. Most were done in Northern France, and most were fighter aircraft, three German, and seven Allied ones. The Sercus dig is not mentioned on this site.

On 9/3/2007, about two months after filing the charges, author sends an email to the Kent Police, requesting information on progress. By 10/4/2007 no reply was received. The promise was not kept, to report back what the British Police can and shall do. It seems that the British Police shall do nothing about the matter.

Via RAF Air Historical Branch, the Joint Casualty & Compassionate Center (JCCC), Historic Casework Unit, of the Ministry of Defence takes an interest in the matter. They enquire with Kent Police about the status of the crime report. On April 22nd, 2008, JCCC receives a letter from Kent Police, stating that the case has not been investigated, and that it has been passed on to the Customs and Excise unit. It is disappointing to see that the Police needed 15 months to do little more than to pass the matter on to another desk.

12/5/2007

In Wizernes, Pas-de-Calais, Nord, France, a conference is held at 'La Coupule'. The Germans build a huge bunker here, planning to assemble and launch V-2 rockets from here. Numerous Allied air attacks saw to it that the site never became operational. Since 1997, it houses a very well furnished World War Two museum, named after the enormous concrete dome.

Wizernes 070512 La Coupule

The conference has a title: 'Tombés du Ciel - les aviateurs abattus au dessus du Nord-Pas de Calais'. It is organized by Yves Le Maner, director of La Coupule. The main target of the conference is to increase public and official awareness of the heritage that is still buried in the soil of this area of France. This is triggered by the recent illegal excavations of WW2 aircraft. Mr. Yves Roumégoux, conservateur du Patrimoine, Institut national du Patrimoine, pleads for better legislation regarding aircraft wreck excavations, and the distribution of parts found. What is needed most of all, is an awareness of locals, including town officials and the Gendarmerie, that excavations may only be done in a controlled way. Meaning with permission of the Service Archeologique. And that means proper documentation of an excavation, and making that documentation available to the public domain.

The conference theme is supported by surveys of the whereabouts of archival material. Mr. Sebastian Cox, director of the RAF Air Historical Branch, informs about the relevant British archives. Mme. Agnès Beylot, Conservateur en chef du Patrimoine, Service historique de l'armée de l'air,

does so about the French archives. Mr. Jocelyn Leclercq, private Air War researcher, adds to this regarding American and German archives, and municipal archives in France. Mr. Hughes Chevalier, private Air War Researcher, gives a lecture on the 'oral archive', the accounts of crash eyewitnesses. As problematic as the oral archive may have become after 60 years, it is still indispensable.

Left to right: Mme. Agnès Beylot, Yves Le Maner, Sebastian Cox Wizernes 070512 congress 2


The conference theme is finally supported by surveys of the air War over Northern France. The surveys were produced, and are presentated, by Joss Leclercq. Author feels that these belong to the few bits of new information, results of original research, presented at this conference. The key people, Beylot, Cox & Le Maner, had nothing of the kind to offer. They restricted themselves to presentations of knowledge already available to their specialist audience.

Jean-Pierre Moille was present too. He greeted author with the words 'Tu m'a causé beaucoup d'annui avec KLM!' His lack of manners, even agressiveness, was such that author ended this non-conversation at that point.

Later it transpired that Jean-Pierre Moille has led Albert Plesman to believe that this meeting, attended by officials from the Royal Air Force too, was in the service of finding back Jan Plesman. The only service to the Jan Plesman case, given on this conference, would be the call for awareness of local officials for the matter of the illegal digs. But local officials were not, or hardly, present at this conference. Author talked to Mr. Sebastian Cox, who stated that he would raise the matter of the illegal digs on the basis of my report to the Kent Police. Mr. Cox was spirited away from the conversation with author by Yves le Maner, when I exceeded the three minutes timezone in which Le Maner did not know what to do. Several weeks later author received notice from Mr. Cox, that he had passed on the matter within the Ministry of Defence. After that, nothing was heard. At the time of writing, this is three months ago. How is it, that author cannot be impressed by any of this? These people have a knowledgeable and serious look over their spectacles, but in reality they have a job, that they shall not endanger by anything creative that could lead to results that are not defined in their job description. They present themselves as scientists, but their job dependency leads them to become the antithesis of a scientific mind.

Joss Leclercq informed author at an early stage that this conference would take place. Author asked the controlling manager, Yves Le Maner, for an invitation. That was granted by email, but in fact an invitation never came. Mr. Le Maner was clearly disturbed when author shook his hand at the start of his conference. What is the problem that these people have? The 'not invented here' syndrome, the Napoleon syndrome? Paris is not the center of the world. Author has offered to these guys whatever he had, assuming that cooperation would follow, so as to get the job done of finding back Jan Plesman. A cooperation did not materialize. The other guys, meaning Moille and Le Maner, just ran off with the data, presenting it as their own in newspaper publications. All this has been seen by author so many times before. The verdict has to be that these people fail to qualify for the cooperation needed to get a complex job done. Fortunately there are others. Even many of them. Author likes to believe that in this field of historical research it is easier to find good & scientifically honest others than in the field of competitive business. We can do without the weak ones, who act basically as dictated not by a job at hand, but by their own personal career agendas.

18. Two more fighter aircraft crash sites found

14-15/3/2007

Armed with the letter of recommendation from the Mayor of Hazebrouck, author sets out to find and photograph the 145 craters visible in the 1947 aerial pictures. One large crater is found to be a farm pond today. The farmer explains that it had been there long before the War. But he knows an elderly farmer, who knows about an aircraft that crashed on his ground. From this farmer we went to the next and the next, and the end result was two crash sites indicated and pinpointed. One believed to be a Spitfire that crashed in 1941, the other believed to be a Mustang that crashed in 1944. Both pilots baled out. One fell to his death, the other was taken POW. The eyewitnesses are certain that the wrecks are still where the aircraft fell.

Candidate for the Spitfire, pending the unearthing of the wreck, and according to Joss Leclercq:

Por. pil. (F/O.) Wiktor Stanislaw Strzembosz, PAF Nr. P0897, born Rokiciny 12/7/1914, crashed at La Motte, 8/7/1941 with Spitfire Mk. IIb Nr. P8669 RF-M of 303 Squadron, flying from RAF Northolt.

Source: Gretzyngier, R., Matusiak, W., Wójcik, W., Zieliński, J.; "Kuczci Poległych Lotnikow 1939-1945", Warszawa 2006, page 134

F/O. W. S. Strzembosz baled from his aircraft, but his chute failed to open. His body was found about a kilometer Southeast of the crash site.

Source: crash eyewitness, name witheld here.

He was identified by the Germans and buried in nearby Merville Communal Cemetery, where his grave remains to this day.

303 'Kosciuszko' Squadron was flying top cover for Circus 40, a bomber raid against Lille railway station. Take off at 14.30h. 303 Squadron was led by S/Ldr. Major Tadeusz Aleksander Arentowicz, PAF Nr. P0251, in Spitfire Mk. IIb Nr. P8502 RF-C. During the bombing runs, the fighters were attacked by German fighter aircraft. Both Arentowicz and Strzembosz were hit. The other pilots of the Squadron saw Arentowicz heading for home and losing altitude in the Duinkerken area. Aviator and aircraft were lost in the Channel. A Lysander search was in vain. S/Ldr. T.A. Arentowicz remained missing-in-action.

Source: Cumft O., Kujawa H. K.; "Ksiega lotnikow polskich 1939-1946", Wydawnictwo MON, Warszawa 1989, translated by Krystyna Stopa, via Jos van Alphen

'La Motte' must be La Motte au Bois, the village in the center of the Forêt de Nieppe, South of Hazebrouck. Close enough to where a Spitfire wreck is claimed to be buried.

As a result of attacks on Circus 40, the Germans claimed no less than eleven Spitfires as shot down in the afternoon of 8/7/1941, almost all of these were claimed as shot down above the coast between Gravelines, France, and Coxyde, Belgium. One exception: Ofw. Walter Meyer of 6./JG 26, claimed a Spitfire shot down near Hazebrouck, 15.40h. This could well be the Strzembosz Spitfire. One was claimed as shot down at the same time, Southeast of Dunkirk, by Uffz. Ullrich Grebe. This could well be the Arentowicz Spitfire.

Source: O.K.L. Fighter Claims, Chef für Ausz. und Dizsiplin Luftwaffen -Personalamt L.P. [A] V Films & Supplementary Claims from Lists, Reich & Western Front, 1941

We do not yet have one or more candidates for a Mustang loss near Hazebrouck in 1944, but that shall come.

As, on the basis of this information, these aircraft are not Jan Plesman's Spitfire, the information is passed on to Joss Leclercq for proper processing. He states that these crash sites were not registered before. Copy of the report to the Préfecture de la Région Nord – Pas-de-Calais, le conservateur régional de l'archéologie. Names of eyewitnesses, and the locations of the wrecks, are witheld here, so as to prevent illegal digs. The farmers involved received a letter thanking them, and to ask them to call the Gendarmerie, should they see unauthorized persons with magnetometers in their fields.

This adds up to four fighter aircraft found within a year, in the Plesman search area and immediate surroundings. Two Messerschmitts, one Spitfire and one Mustang. One salvaged with pilot, one dug out illegally, and two without pilots, and waiting for a proper excavation. This raises the hope that more can be found. Crashing fighter aircraft tend to vanish from sight in this area.

17/08/2007

Albert Plesman and wife Tita are in Holland. Albert's book 'Jan Plesman, a Flying Dutchmen', 2004, has been translated into Dutch, and published by Aksent, Soesterberg. Several photo's and documents were added, and a last page, mentioning efforts to locate his brother's remains in the Hazebroock area. No sources for that are mentioned. There are no other text additions, according to Albert.

Author asks Albert where he wants his brother's remains buried, should these be found. He immediately answers 'in the family grave'. There is no question whatsoever about that. He is asked if this wish has been put on paper. It has not, and author advises to do so. Earlier Albert had mentioned that some of the Plesman family are annoyed by the search for Jan. Albert believes that this search generates publicity that those family members do not wish to see. If true, and considering that Albert, as vital as he is, shall not live forever, the advice was given to put the burial wish to paper. Done here too. By the way, Albert's remarkable vitality cannot have come about without the very good care taken of him by Tita, the Italian nurse who became and remained his wife from shortly after the War. It is still quite evident that she has been a stunning beauty in younger years. She is fluent in Italian, French, Dutch and English. Albert may not have been rewarded adequately by the officials, for his daring exploits in Borneo, using Japanese warplanes to locate the Jappenkampen, and to save the lives of hundreds of the occupants of these camps. But author feels that he was rewarded in personal life more than many.

After that we go out and visit the family grave, in Den Haag Algemene Begraafplaats, two bowshots away from the former KLM main office. The family grave is close to the Monument for Dutch servicemen who fell during The May 1940 attack on The Hague. The grave is a modestly normal one, in comparison to other graves in this cemetery. Albert has purchased a long lasting plant that is going to show a multitude of purple flowers. He mentions that the family grave has space for him too, but his tone of voice could indicate that he does not believe that the matter of his own burial shall ever be raised...

Why is he so explicit that Jan should be buried here? He explains that this would have been his father's wish. The family grave contains the remains of his brother Hans Plesman, killed in a post War plane crash, Dr. Albert Plesman, his father, and Suus Plesman-van Eijk, his mother. He explains that Jan was the favourite son of his father, because of his intelligence & character. Albert Jr was the cross one, the rebel, and Hans was the most balanced one. He has no doubt that his father would wish to have his sons buried with him.

Meanwhile, someone within the Plesman family should see to it that the missing bronze letter & number of the family grave text are replaced.


Albert Plesman caring for the family grave in Den Haag Algemene Begraafplaats Plesman family grave 070817-1

19. Finding official backup

As author took seriously ill in the second half of 2007, things came to a halt. The winter season, in which low crops would allow ground radar searches, passed. As strength was coming back again, new efforts to get things moving were undertaken. One of these was a discussion, 25-06-2008, with Captain Ing Paul Petersen, staff officer coordinating aircraft salvage operations, of the Royal Dutch Airforce. Author had assumed that he is the head of the Salvage & Identification Service, BID, but he is not. He is Airforce, the BID is BID KL, meaning Army. He engages the assistance of the BID KL whenever required. As the Plesman matter, being both a cold case and outside the borders of The Netherlands, is not controlled by the Directive on the work of the BID, he needs orders from above. This means requesting the Minister that the BID be set free to do this job. A request that is to come from the Plesman family, as anything elso shall most likely be ignored. So be it. The Minister of choice is the one of Internal Affairs, as his office produced the Directive on the work of the BID. Let's hope that this Minister shall consider this request as well placed on his desk. It is going to take a lot of time and effort to find the proper paths, politically, diplomatically, and financially, and to deal with all obstacles that shall be found on these paths. The good thing is that the BID has expressed an interest in the matter, even if that may only have come from concern that private initiative could lead to illegal actions regarding human remains. But nevertheless this is a first expression of interest coming from an official Dutch party. Author would greatly welcome it if the BID would take over the entire matter, and do what needs to be done to achieve results. Meanwhile, I had better proceed on the assumption that this may not happen.



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