War horse – early devel­op­ment of the Fw 190

Early devel­op­ment of the Fw 190

Aviation Classics - - CONTENTS -

Focke-wulf was con­tracted to de­velop a front line sin­gle-seat fighter to op­er­ate along­side the Messer­schmitt Bf 109 in 1938 and designer Kurt Tank was determined that it would be a ver y dif­fer­ent breed from its stable­mate.

When Willy Messer­schmitt cre­ated the Bf 109 in 1934 there was very lit­tle else in the world to match its sim­ple yet highly ef­fi­cient de­sign. It wasn’t per­fect but it sur­passed its con­tem­po­raries in al­most ev­ery re­spect. By the time Kurt Tank and his team came to de­sign the Fw 190 in 1938, the Bf 109 had seen ac­tion in the Span­ish Civil War and its im­per­fec­tions had be­come read­ily ap­par­ent. The Ger­mans had also be­come in­creas­ingly con­cerned about the Bri­tish Su­per­ma­rine Spit­fire. It was feared, with some jus­ti­fi­ca­tion, that this ad­vanced fighter was al­ready able to out­per­form the Bf 109. There­fore, Tank set out to de­velop an aero­plane that would not only ad­dress the Bf 109’s flaws but also have a rea­son­able chance of best­ing the Spit­fire – a tall or­der. It helped that Tank was given leave to ex­am­ine pro­duc­tion Bf 109 ma­chines up close and in de­tail be­fore get­ting started. De­scrib­ing the de­sign phi­los­o­phy be­hind the Fw 190, Kurt Tank told avi­a­tion his­to­rian Dr Al­fred Price: “The Messer­schmitt 109 and the Bri­tish Spit­fire, the two fastest fighters in the world at the time we be­gan work on the Fw 190, could both be summed up as a very large en­gine on the front of the small­est pos­si­ble air­frame; in each case ar­ma­ment had been added al­most as an af­ter­thought. “Th­ese de­signs, both of which ad­mit­tedly proved suc­cess­ful, could be likened to race­horses: given the right amount of pam­per­ing and an easy course, they could out­run al­most any­thing. But the mo­ment the go­ing be­came tough they were li­able to fal­ter. “Dur­ing the First World War, I served in the cav­alry and in the in­fantry. I had seen the harsh con­di­tions un­der which mil­i­tary equip­ment had to work in wartime. I felt sure that a quite dif­fer­ent breed of fighter would also have a

place in any fu­ture con­flict: one that could op­er­ate from ill-pre­pared front line air­fields; one that could be flown and main­tained by men who had re­ceived only a short train­ing; and one that could ab­sorb a rea­son­able amount of battle dam­age and still get back. “This was the back­ground think­ing be­hind the Focke-wulf 190. It was to be not a ‘race­horse’ but a Dien­stpferd, a cav­alry horse.” The Fw 190 would be tough and de­pend­able but it would also have to be able to keep up with the ‘race­horses’ where it mat­tered. The air­frame would be sturdy enough to carry heav­ier weapons than the Bf 109 could man­age but not so heavy that it in­curred a per­for­mance penalty. The need for good all-round visibility was also a key con­sid­er­a­tion. The Bf 109’s cock­pit canopy fea­tured heavy frames and the rear­ward view was less than sat­is­fac­tory, there­fore Tank’s team came up with a slop­ing frame­less ‘bub­ble’ canopy. For the pow­er­plant, an air-cooled ra­dial en­gine was cho­sen be­cause it could soak up battle dam­age with­out fail­ing – where a dam­aged liq­uid-cooled unit might rapidly run dry and seize – and be­cause Tank al­ready had one in mind, the 14-cylin­der BMW 139. With Junkers’ Jumo 210 de­sign reach­ing the lim­its of its po­ten­tial, its fol­low-on the Jumo 211 be­ing fit­ted to the Ju 87, Ju 88 and Heinkel He 111 and Daim­ler-benz’s DB 601A al­ready ear­marked for the Bf 109 and Bf 110, it also made sense to choose an en­gine that was not com­mit­ted else­where. The BMW 139 was de­signed with two rows of seven cylin­ders po­si­tioned back to back. Com­pared with an in­line de­sign such as the DB 601, it had a higher power to weight ra­tio but at the cost of gen­er­at­ing an enor­mous amount of heat in a small area. Tank said: “So the air-cooled ra­dial en­gine was fit­ted to the Fw 190. When the fighter went into ac­tion the re­silience of this type of power plant was proved again and again. There were sev­eral oc­ca­sions when th­ese fighters re­turned home and made nor­mal land­ings, hav­ing had whole cylin­ders shot away. “Once its cool­ing sys­tem had been pierced and the liq­uid al­lowed to drain away, the run­ning life of the equiv­a­lent liq­uid-cooled en­gine would have been about three min­utes.” With all th­ese re­quire­ments in mind, Tank’s de­sign team sub­mit­ted a se­ries of

de­signs to the RLM. One of them was cho­sen and Focke-wulf was given an or­der to pro­ceed with the con­struc­tion of pro­to­types. In work­ing out how to build the Fw 190, Tank’s team de­cided that sim­plic­ity was crit­i­cal. The en­gine was at­tached di­rectly to the mono­coque fuse­lage, avoid­ing the need for en­gine mounts, and two re­mov­able self­seal­ing fuel tanks were fit­ted di­rectly be­neath the pi­lot. The smaller tank, of 232 litres, was be­low the pi­lot’s legs and the larger, of 292 litres, was di­rectly be­hind it un­der and be­hind his seat. This gave the Fw 190 more than twice the fuel ca­pac­ity and there­fore twice the range of the Bf 109, which could only carry 250 litres in­ter­nally. The wings, fea­tur­ing split flaps, were built as a sep­a­rate piece and a se­ries of ridges and cor­re­spond­ing grooves al­lowed them to be quickly moved into the cor­rect po­si­tion on the fuse­lage when fit­ted. Af­ter the trou­ble caused by the hy­drauli­cally op­er­ated un­der­car­riage on the Fw 159, the Fw 190 used a straight­for­ward and re­li­able sys­tem of ca­bles that were elec­tri­cally wound in or out on drums to raise and lower its main and tail wheels. The only ex­cep­tions were the first two pro­to­types, which both had hy­draulic sys­tems. The Bf 109 had a nar­row track un­der­car­riage where the bulky wheels re­tracted out­wards into the wings, re­strict­ing what weapons could be fit­ted there. In con­trast, the Fw 190 had a wide track and the wheels re­tracted in­wards un­der the fuse­lage, re­duc­ing in­tru­sion into the wings and free­ing up space. The first ar­ma­ment ar­range­ment to be fit­ted was two ma­chine guns and two can­non – a 7.9mm MG 17 with 800 rounds and a 20mm MG 151 with 160 rounds in each wing, close to the fuse­lage. Ease of main­te­nance was an­other con­sid­er­a­tion in the Fw 190’s de­sign. Com­po­nents that would re­quire fre­quent ser­vic­ing were po­si­tioned within easy reach and large ac­cess pan­els were pro­vided to make the tech­ni­cian’s job eas­ier. Climb­ing aboard the fighter, which stood nearly 4m tall at its high­est point com­pared to the Bf 109’s rel­a­tively diminu­tive 2.6m, was made eas­ier with the ad­di­tion of a re­tractable step which popped out of the lower edge of the fuse­lage on the port side aft of the wing root. Then there was a spring loaded hand­hold and a fur­ther step. In­side the cock­pit, the seat was semire­clined and ver­ti­cally ad­justable over a range of 4in. A lot of work was done to en­sure that in­stru­ments were laid out in a log­i­cal way, with ev­ery­thing eas­ily to hand. A 1000W gen­er­a­tor pro­vided in­ter­nal sys­tems with a 24v power sup­ply. The fuel-in­jected BMW 139 en­gine, which de­vel­oped 1500hp on take­off, drove a three­bladed Verein­gite Deutsche Me­tall­w­erke elec­tro-hy­draulic vari­able pitch pro­pel­ler mea­sur­ing 3.4m in di­am­e­ter. Over this was fit­ted a large Dop­pel­haube ducted spin­ner in­tended to re­duce drag and, it had been cal­cu­lated, im­prove the air­craft’s top speed by about 25mph. As with all of Tank’s pre­vi­ous Focke-wulf air­craft, while he set the Fw 190’s de­sign pa­ram­e­ters and over­saw the project, the de­tailed de­sign was down to his team. The work was co­or­di­nated by his as­sis­tant Willi Käther, en­gi­neer Ru­dolf Blaser de­signed the struc­ture and test pi­lots Hans San­der and Kurt Mel­horn both con­trib­uted from an early stage. A wooden mock-up was con­structed to begin with, dur­ing the au­tumn of 1938, then work was started on the pro­to­type, Fw 190 V1. The ‘V’ stood for ‘Ver­suchs’ or ‘ex­per­i­men­tal’. The first flight of the fin­ished prod­uct took place on June 1, 1939, with San­der at the con­trols. While he was im­pressed by the air­craft’s per­for­mance, he found an­other as­pect of the flight less sat­is­fac­tory: “For the first flight, I wore only a thin fly­ing suit over my nor­mal un­der­wear, socks, or­di­nary shoes, and a fly­ing hel­met with my oxy­gen mask hang­ing loose, yet soon af­ter take­off I be­gan to sweat pro­fusely. “The rear of the en­gine was hard up against the front wall of the cock­pit, and my feet and rud­der ped­als were ei­ther side of the en­gine ac­ces­sories. The tem­per­a­ture in the cock­pit rose to 55ºc. I felt as though I was sit­ting with my feet in the fire. The heat was bear­able but ever since I have had some sym­pa­thy for a steak on a grill.” San­der also had to put his oxy­gen mask on be­cause en­gine ex­haust fumes were be­gin­ning to leak through the im­prop­erly sealed edges of the canopy. De­spite th­ese prob­lems, the test was deemed a suc­cess. The Fw 190 V1, given the civil reg­is­tra­tion D-OPZE, was shown to Adolf Hitler, Her­mann Göring, Ernst Udet, Erhart Milch and Gen­eral Wil­helm Kei­tel just over a month later on July 3, 1939. At this stage it had no ar­ma­ment fit­ted and there was a prob­lem with the V1’s hy­draulic un­der­car­riage up-lock mech­a­nism. The land­ing gear would rise and lock cor­rectly af­ter take­off but then, dur­ing aerial ma­noeu­vres, the oleo legs would be­come un­locked and sag down. This was even­tu­ally fixed by fit­ting a new stronger mech­a­nism based on a bomb re­lease shackle.

En­gine prob­lems

As tests con­tin­ued, cool­ing prob­lems per­sisted and Focke-wulf’s Dop­pel­haube spin­ner was iden­ti­fied as the source of the prob­lem by BMW. Focke-wulf kept the spin­ner how­ever, for the aero­dy­namic rea­sons pre­vi­ously stated. A test pi­lot from the Re­ich­lin ex­per­i­men­tal cen­tre, Hein­rich Beau­vais, vis­ited Focke-wulf on Oc­to­ber 31, 1939, to make a for­mal as­sess­ment of D-OPZE, which was now be­ing re-reg­is­tered as FO+LY un­der a new sys­tem be­ing im­ple­mented across Ger­many. He later wrote: “We in­stinc­tively pre­ferred the Fw 190 over the Bf 109 from the very

start. The rea­sons for this are de­tailed in our re­port. The Fw 190’s con­trol forces are sig­nif­i­cantly lower at high speeds, and its rate of roll is markedly greater. “Fur­ther­more, its wide-track un­der­car­riage and the su­pe­rior rigid­ity of its air­frame are highly thought of, es­pe­cially in belly-land­ings. The view to the rear is su­pe­rior, and its BMW ra­dial en­gine is less vul­ner­a­ble to en­emy fire. “There was a ten­dency to dis­be­lieve its in­fe­ri­or­ity in turn­ing. Our re­port states that: ‘It has yet to be determined whether the Fw 190 turns tighter than the Bf 109’. In my opin­ion this should be viewed as mis­lead­ing. “It is true that turn­ing radii were not mea­sured, but that did not re­ally mat­ter. What did mat­ter was turn­ing times, and in this re­spect the Bf 109 was clearly su­pe­rior. How­ever, it needed barely four sec­onds to per­form a com­plete roll, com­pared to five sec­onds for the Bf 109.” On the same day the Fw 190 V2, reg­is­tered as FO+LZ, made its first flight with both ma­chine guns and can­non in­stalled. It also had a FUG VII ra­dio and Revi C/12C gun­sight fit­ted. Around this time the Fw 190 was given its Focke-wulf bird name; fol­low­ing on from the tra­di­tion es­tab­lished by the Stieglitz, Stösser, Weihe and the rest it was called Würger (Shrike). Two months later, af­ter suf­fer­ing from the same over­heat­ing prob­lems as FO+LY, the V1, it also had a new 10-bladed cool­ing fan fit­ted be­neath its spin­ner. This helped a lit­tle but failed to cure the prob­lem. BMW per­sisted with its claim that the spin­ner was the prob­lem and Focke-wulf fi­nally re­lented. Com­par­a­tive tests were con­ducted in Jan­uary 1940 us­ing the two pro­to­types with Fw 190 V2 re­tain­ing its Dop­pel­haube while V1’s was re­moved and

re­placed with a straight­for­ward Naca-style cowl­ing of BMW de­sign. Th­ese tri­als re­vealed that far from added to the Fw 190’s top speed, the spin­ner was ac­tu­ally slow­ing it down by about 12mph. In fact, Focke-wulf had failed to ac­count for the inch-wide gap be­tween the spin­ner and the en­gine cowl­ing, which caused air to be sucked through the pro­pel­ler hub caus­ing drag. The Dop­pel­haube con­cept was scrapped and all fu­ture Fw 190s had a Naca-style cowl­ing in­stead. With its new cowl­ing in place, V2 was flown in a per­sonal demon­stra­tion for Göring and an or­der for 40 pre-pro­duc­tion air­craft, known as the Fw 190A-0, fol­lowed. V2, now re-reg­is­tered again as RM+CB, was dam­aged in an ac­ci­dent on March 2, 1940, when it flipped over on to its back dur­ing taxi­ing. Re­paired, it was used for weapons tri­als start­ing in Septem­ber 1940. V1 was taken to Rech­lin for fur­ther flight tri­als on June 11, 1940. Un­for­tu­nately, the over­heat­ing prob­lems of the BMW 139 had proven to be in­cur­able and the en­gine de­sign was scrapped af­ter just 47 units had been pro­duced. Work on Fw 190 V3 and V4, which were near­ing com­ple­tion with fit­tings pre­pared for the 139, was halted. V3 was can­ni­balised for spares and V4 was load tested to de­struc­tion. The loss of the BMW 139 was not a dis­as­ter for the Fw 190 how­ever, as the en­gine man­u­fac­turer had been work­ing on a sim­i­lar model in par­al­lel which was specif­i­cally de­signed for fan cool­ing, the BMW 801 C. In fact, the 801 in­cor­po­rated el­e­ments of both the BMW 139 and an en­gine de­signed by Bramo, a ri­val firm which BMW had ab­sorbed in 1939 – the Bramo 329. The 801 C was roughly the same di­am­e­ter as the BMW 139 and slightly longer but it promised to be even more pow­er­ful, more re­li­able and sig­nif­i­cantly less prone to over­heat­ing than its pre­de­ces­sor. It was also heav­ier. An­other change was the ad­di­tion of a de­vice known as the Kom­man­dogeräte. This clever mech­a­nism au­to­mated the ad­just­ment of man­i­fold pres­sure, com­pres­sor gear shift, fuel mix­ture reg­u­la­tion, ig­ni­tion con­trol and con­stant speed con­trol through pro­pel­ler pitch. Kurt Tank said: “In the­ory, the Kom­man­dogeräte meant that the pi­lot only had to move one con­trol, his throt­tle. I say ‘in the­ory’, be­cause at first the de­vice did not work at all well. All sorts of things went wrong with it. One of the more dis­con­cert­ing things was the rather vi­o­lent au­to­matic switch­ing in and out of the high gear of the su­per­charger as the air­craft climbed through 2650m.

“On one oc­ca­sion I was car­ry­ing out a test with an early ver­sion of the Fw 190 which in­volved a loop at medium altitude. Just as I was near­ing the top of the loop, on my back with lit­tle air­speed, I passed through 2650m and the high gear of the su­per­charger cut in with a jerk. “The change in torque hurled the air­craft into a spin with such sud­den­ness that I be­came com­pletely dis­ori­en­tated. And since there was a ground haze and the sky was over­cast and my ar­ti­fi­cial hori­zon had top­pled, I had no way of know­ing which way was up. “Af­ter a lot of trial and er­ror, and a con­sid­er­able loss in altitude, I man­aged to re­cover from the spin. But the in­ci­dent had given me a lot to think about.” Tank con­tacted BMW im­me­di­ately on land­ing and de­manded that the Kom­man­dogeräte be fixed. BMW’S en­gi­neers con­tin­ued their devel­op­ment work on the de­vice and its prob­lems were grad­u­ally ironed out. The first pro­to­type fit­ted with the BMW 801 C, Fw 190 V5, first flew in April 1940. The ex­tra weight of the en­gine, an­other 150kg, meant that the Fw 190’s air­frame had to be strength­ened to ac­cept it and the un­der­car­riage struts had to be stiff­ened. Due to the larger struc­ture needed to ac­com­mo­date the en­gine, the cock­pit was moved slightly fur­ther aft and the over­all length of the air­craft was in­creased by 6.8cm from 8.73m to 8.798m. With the pi­lot now fur­ther away from the en­gine, the cock­pit re­mained cooler and the ex­tra space at the front of the air­craft was just enough to al­low a pair of ma­chine guns to be fit­ted on to its nose above the en­gine if re­quired. Ear­lier tests had re­vealed that above 270mph the Fw 190’s emer­gency canopy re­lease mech­a­nism was non-func­tional. Air-flow over aero­dy­namic hood held it firmly in po­si­tion, pre­vent­ing the pi­lot from bal­ing out. A bungee cord sys­tem and com­pressed air was tried be­fore it was cal­cu­lated that in or­der to over­come the ex­ter­nal pres­sure, a force equiv­a­lent to 50hp was needed. Designer Ru­dolf Blaser fi­nally came up with a mech­a­nism where a 20mm ex­plo­sive car­tridge pushed a pis­ton which in turn

punched the canopy rear­wards to the point where the air­flow caught it and whipped it smoothly away from the air­frame. In­spired by this in­no­va­tion test pi­lot San­der, who was also a qual­i­fied en­gi­neer, came up with a prim­i­tive ejec­tion seat mech­a­nism for the Fw 190 but he was un­able to give the project his full at­ten­tion and when his ini­tial ef­forts demon­strated that the ex­plo­sive car­tridges avail­able were not pow­er­ful enough to pro­pel the pi­lot far enough to avoid the air­craft’s tail the idea was dropped.

FW 190A-0 AND A-1

The ex­tra weight of the BMW 801 C en­gine cou­pled with the heav­ier struc­ture re­quired to cope with it, and the other mod­i­fi­ca­tions, had a di­rect im­pact on the Fw 190’s ma­noeu­vra­bil­ity. The wing load­ing had in­creased and flight tests us­ing V5 quickly re­vealed the im­pact this had on the air­craft’s han­dling. It was de­cided that the best way to re­duce wing load­ing back to ac­cept­able lev­els and re­store the much ad­mired han­dling of the Fw 190 V1 and V2 was to sim­ply ex­tend the wings. While this work was be­ing dis­cussed, pro­to­type V6 was com­pleted and took its first flight on May 31, 1940. It suf­fered from prob­lems with its BMW 801 C how­ever and made just nine flights be­fore the orig­i­nal unit had to be swapped for a new one. Both V5 and V6 each armed with a quar­tet of 7.9mm MG 17 ma­chine guns – two in the wing roots and two on the nose. This con­fig­u­ra­tion meant that they were ret­ro­spec­tively re­ferred to as Fw 190A-0/U1S. The ‘U’ stood for ‘Um­rüst bausatz’ or ‘con­ver­sion kit’ – an ‘Um­bau’ was a change to the air­craft’s con­fig­u­ra­tion that could only be car­ried out at the fac­tory or on rare oc­ca­sions in the field by an ac­cred­ited Focke-wulf sub­con­trac­tor. Af­ter the two Fw 190A-0/U1 air­craft a se­ries of nine more A-0s were pro­duced, tak­ing their first flight be­tween July and Oc­to­ber 1940 and be­ing used to test var­i­ous dif­fer­ent weapons lay­outs, en­gine mod­i­fi­ca­tions and other ex­per­i­men­tal al­ter­ations to the air­craft’s de­sign. Fi­nally, on Oc­to­ber 10, 1940, Fw 190A-0 WNR. 0016 (the 16th Fw 190 built af­ter the six ‘Ver­suchs’ air­craft and the nine A-0s), coded KB+PR, made its fly­ing de­but with an en­larged wing. Each wingtip had been ex­tended by just over 50cm, giv­ing it a wingspan of 10.5m, com­pared to 9.5m of all the ear­lier ex­am­ples. Wing area was cor­re­spond­ingly in­creased from 14.9sq m to 18.3sq m. The amount the wing ta­pered was also re­duced so that the wingtip it­self took on a squarer look. In later ver­sions of the Fw 190, the area of the tailplane was also in­creased. Per­for­mance was still worse than the small­wing BMW 139 Fw 190s how­ever, with top speed at 18,372ft down from 432mph to 426mph and range down to 671 miles from 684 miles. Ser­vice ceil­ing was im­proved though, from 36,090ft to 37,400ft. The new wing was there­after re­ferred to as the V5g and Fw 190s with­out it were V5ks, the ‘g’ be­ing for ‘grosser’ (larger) and the ‘k’ be­ing for ‘kleiner’ (smaller), and was in­stalled on all sub­se­quent Fw 190A air­craft. In early 1941, WNR. 0007 be­came the pro­to­type for the Fw 190A-1 and was given the new pro­duc­tion WNR. 190.0110.001. The 190 was the type, the 011 meant ‘A-1’, the 0 was the man­u­fac­turer – Focke-wulf – and the 001 was the in­di­vid­ual air­craft’s se­rial num­ber. Other com­pa­nies that later built the Fw 190 had their own num­bers where Focke-wulf had the 0. Ago had 2, Arado had 5 and 6 and Fieseler had 7. As the tem­plate for the front line fighters that were to fol­low, WNR. 190.0110.001 had a BMW 801 C-1 en­gine gen­er­at­ing 1560hp at sea level, a pair of MG 17s over the en­gine and two more in the wing roots. There was also pro­vi­sion for the fit­ment of two 20mm can­non in outer wing po­si­tions. Bre­men was bombed for the first time by the RAF on three con­sec­u­tive nights from Jan­uary 1-4, 1941. A Bri­tish Cabi­net Of­fice re­port given on Jan­uary 2 af­ter the first raid, which in­volved 148 bombers, sug­gested that it had been a great suc­cess with no Bri­tish bombers lost. While the brunt of the attack was born by Bre­men it­self, with firestorms rag­ing across the city, the Focke-wulf fac­tory was also tar­geted and suf­fered dam­age. The first Luft­waffe unit to con­vert to the Fw 190 was the II. Gruppe of Jagdgeschwader 26 (II./JG 26). In March 1941, JG 26 of­fi­cers Oblt Otto Behrens and Lt Karl Bor­ris were sec­onded to es­tab­lish and lead an ex­per­i­men­tal unit, Er­probungsstaffel 190, at Rech­lin-roggen­thin to ready the Fw 190 for ac­tive ser­vice with the Luft­waffe. Both men had tech­ni­cal back­grounds and they were given a team of 30 ground crew and half a dozen A-0s to work with.

Bor­ris found the Fw 190 im­pres­sively ro­bust and a plea­sure to fly but re­alised that its BMW 801 C en­gine was the source of se­ri­ous and on­go­ing prob­lems. He said: “What­ever could pos­si­bly go wrong with it did. We hardly dared to leave the im­me­di­ate vicin­ity of the air­field with our six pro­to­type ma­chines. “Oil lines rup­tured. The heav­ily ar­moured oil cooler ring in front of the en­gine of­ten broke. The bot­tom cylin­der of the rear row seized again and again, since the oil pump and the cool­ing sur­faces were too small. Leak­ing fuel lines left the pi­lots in a dazed state from the fumes, un­able to climb out of their aero­planes unaided.” Focke-wulf suf­fered a set­back on the night of March 12/13, 1941, when the RAF sent 86 Vick­ers Welling­tons and Bris­tol Blen­heim bombers to attack Bre­men. The bulk of the force, the 54 Welling­tons, tar­geted the Focke-wulf fac­tory and suc­ceeded in destroying jig as­sem­blies and part of the com­pany’s de­sign of­fices. The attack was not en­tirely un­ex­pected how­ever. It was by now clear that Bre­men, be­ing close to Ger­many’s north coast and eas­ily lo­cated thanks to its po­si­tion strad­dling the largest wa­ter­way in the re­gion, the River Weser, was an easy tar­get. As such, it would be hit re­peat­edly through­out the rest of the war. Plans had al­ready been set in mo­tion, how­ever, to con­struct a large new Focke-wulf pro­duc­tion fa­cil­ity nearly 600 miles fur­ther to the east – a 100 acre site at Marien­burg, East Prus­sia, known to­day as Mal­bork in Poland. At the same time, much of the Luft­waffe’s strength was be­ing drawn away to the east as prepa­ra­tions for the in­va­sion of the Soviet Union, Op­er­a­tion Bar­barossa, en­tered their fi­nal stages. By June 28, 1941, there were just two com­plete Jagdgeschwader (fighter wings) left in the west – JG 2 and 26. Be­tween them they could field a to­tal of 140 ser­vice­able Messer­schmitt Bf 109Es and Fs. In July 1941, de­spite on­go­ing en­gine dif­fi­cul­ties which left some at the RLM won­der­ing whether the Fw 190 pro­gramme should be dis­con­tin­ued, Behrens and Bor­ris’ unit was moved to Le Bour­get air­field near Paris to begin the con­ver­sion train­ing of II./JG 26. It was a slow process due to the on­go­ing tech­ni­cal prob­lems. Two of the new fighters were lost on Au­gust 7 when they suf­fered en­gine fail­ures and crashed, an­other on Au­gust 9. BMW was re­luc­tant to take re­spon­si­bil­ity and was strug­gling to make the ra­dial in the se­ries, the BMW 801 D, ready for ser­vice. The big­gest prob­lem the com­pany faced was a lack of high qual­ity met­als which could be used to cre­ate heat-re­sis­tant al­lots. En­gines fre­quently suf­fered se­vere heat dam­age af­ter just a few hours in op­er­a­tion, ne­ces­si­tat­ing a com­plete rebuild or re­place­ment. Nev­er­the­less, by the end of Au­gust the whole of II./JG 26 was work­ing up on the Fw 190. The unit was then trans­ferred to first Maldeghem and then Moorsele and Wevel­ghem in Bel­gium. The first loss of a Fw 190 on the front line was to ‘friendly’ fire on Au­gust 29 when anti-air­craft guns near Dunkirk opened up on 6./JG 26’s Leut­nant Heinz Schenk. He was shot down and killed. By Oc­to­ber, III./JG 26 based at Co­quelles, near Calais, had also be­gun con­vert­ing to the Fw 190 and it was this unit’s tech­ni­cal of­fi­cer, Oblt Rolf Schroedter, who fi­nally found a work­able so­lu­tion to the BMW en­gine’s over­heat­ing prob­lems. Af­ter the usual round of fail­ures suf­fered by the en­gines of Fw 190s III./JG 26 had been given, Schroedter col­lected up all the failed units and had them sent to his Gruppe’s re­pair shop. Ex­am­in­ing all the failed en­gines to­gether en­abled Schroedter’s team to quickly iden­tify the source of the prob­lem. It was determined that the ex­haust sys­tem was to blame and sim­ply rerout­ing it re­duced the tem­per­a­ture of the bot­tom cylin­der of the rear row – thereby re­mov­ing the sin­gle great­est source of en­gine fail­ure on the Fw 190. Schroedter’s ‘quick fix’ was adopted as a fac­tory mod­i­fi­ca­tion and soon BMW 801 C and later D units could run to more than 100 hours with­out suf­fer­ing crip­pling heat dam­age. From June 1941 to May 1942, Focke-wulf built a to­tal of 101 Fw 190A-1 fighters. The next ma­jor up­grade, the Fw 190A-2, had been pre­pared and two sub­con­trac­tors – Arado at Warnemünde and AGO at Osch­er­sleben – were gear­ing up to pro­duce it en masse. More than this, the Fw 190 had now be­come a front line fight­ing ma­chine and was be­gin­ning to en­counter en­emy ma­chines in the skies over France.

Edi­tor’s col­lec­tion

Test pi­lot Hans San­der fires up the en­gine of Fw 190 V1.the metal panel be­hind the BMW 139 en­gine’s ex­hausts has al­ready be­come heav­ily black­ened.

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Focke-wulf chief designer and chief ex­ec­u­tive Kurt Tank seated in an Fw 190. While Tank ap­proved the air­craft’s ba­sic lay­out, he read­ily ac­knowl­edged that the de­tail de­sign work and on­go­ing devel­op­ment was car­ried out by his team. A wooden model of the Fw 190 V1 built in 1938. It is marked up to show how the air­craft it­self will be con­structed. The al­most-com­pleted air­frame of Fw 190 V1 at Focke-wulf’s Bre­men fac­tory.

Edi­tor’s col­lec­tion Edi­tor’s col­lec­tion Edi­tor’s col­lec­tion

The stir­rup step of Fw 190 V1 re­mains un­re­tracted in this side view of an en­gine run-up test. At this stage the air­craft has not been painted and re­mains in bare metal fin­ish. The Fw 190 V1 with Dop­pel­haube spin­ner fit­ted over its VDM pro­pel­ler. Based on wind tun­nel tests it was cal­cu­lated that the large ducted spin­ner would im­prove the air­craft’s top speed by 25mph.th­ese failed to ac­count for the nec­es­sary gap be­tween the spin­ner and the en­gine hous­ing – which caused so much drag it com­pletely negated any aero­dy­namic benefits. Fit­ted with a con­ven­tional Bmw-de­signed Naca-style cowl­ing, Fw 190 V1 no longer suf­fered ad­di­tional drag from its Dop­pel­haube spin­ner but was still prone to over­heat­ing.

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With its civil reg­is­tra­tion, D-OPZE, clearly vis­i­ble on the un­der­side of its wings, Fw 190 V1 comes in to land. Now fully painted, Fw 190 V1 pre­pares for yet an­other test flight. The tail wheel of Fw 190 V1 lifts off the con­crete run­way at Focke-wulf’s Bre­men fa­cil­ity as a test flight gets un­der way. Chief of the Air Min­istry’s tech­ni­cal of­fice Ernst Udet, cen­tre, dis­cusses the Fw 190 with his chief en­gi­neer Rulof Lucht, left, a for­mer naval avi­a­tor, and the chief test pi­lot of the Rech­lin Luft­waffe test cen­tre Carl Francke, right.

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An un­painted Fw 190 V5 is wheeled across Focke-wulf’s Bre­men fa­cil­ity. Shad­owed in the back­ground is an early Fw 189 Uhu. First flown in April 1940,V5 was the third Fw 190 pro­to­type com­pleted and the first to be fit­ted with the BMW 801 C.AS a con­se­quence its fuse­lage is slightly longer than that of V1 and V2, and the cock­pit is fur­ther back from the en­gine. The 10 blades of the cool­ing fan in­stalled over the BMW 139 on Fw 190 V1 are clearly vis­i­ble in this for­ward view. The tech­ni­cal of­fi­cer of II./JG 26, Karl Bor­ris, was both a pi­lot and a qual­i­fied en­gi­neer. He was hugely im­pressed by the Fw 190’s han­dling char­ac­ter­is­tics but soon re­alised that its en­gine was the source of se­ri­ous on­go­ing dif­fi­cul­ties.

Nim­bus227 Edi­tor’s col­lec­tion Edi­tor’s col­lec­tion

The mighty 14-cylin­der BMW 801 en­gine. De­signed to fea­ture a 12-bladed cool­ing fan from the out­set, it was ini­tially be­dev­illed with over­heat­ing prob­lems like its pre­de­ces­sor, the BMW 139. A quar­tet of pre-pro­duc­tion Fw 190A-0 air­craft.the ma­chine in the fore­ground, WNR. 0010, man­aged 30 flights with its BMW 801 C-0 en­gine – more than most of its con­tem­po­raries. D-OPZE not only un­der­went a change of nose dur­ing its devel­op­ment, it also changed reg­is­tra­tion to the mil­i­tary code FO+LY. It made its first flight in this form on Jan­uary 25, 1940.

Edi­tor’s col­lec­tion Edi­tor’s col­lec­tion Edi­tor’s col­lec­tion Edi­tor’s col­lec­tion

This Fw 190A-1, WNR. 0110.098, was used to test the Fw 190’s abil­ity to carry up to eight 50kg SC 50 bombs. Fi­nal as­sem­bly of Fw 190s on the Focke-wulf pro­duc­tion line at Bre­men.the large pan­els that al­lowed easy ac­cess to the BMW 801 en­gine are clearly vis­i­ble. Eight Fw 190A-0s lined up for in­spec­tion. Clos­est to the cam­era is WNR. 0008.This air­craft was fit­ted with a pair of 7.9mm MG 17 ma­chine guns above its en­gine, fir­ing through the pro­pel­ler, and two 13mm MG 131 ma­chine guns in its wing roots. It was used for ar­ma­ment tests but had to have a new en­gine af­ter nine flights, an­other af­ter a fur­ther 12 flights and then an­other, 10 flights af­ter that. One of the last few Fw 190A-1s built, WNR. 0110.0100 ‘Black 13’ was al­lo­cated to 5./JG 26 at Wevel­gem, Bel­gium, in Novem­ber 1941. It was writ­ten-off the fol­low­ing April when its pi­lot, Uffz. Mathais Säckel, ran out of fuel and was forced to make an emer­gency land­ing.

Edi­tor’s col­lec­tion Edi­tor’s col­lec­tion Edi­tor’s col­lec­tion

Com­pleted and ready for de­liv­ery – pro­duc­tion model Fw 190A-1/U1 WNR. 0110.067 TI+DQ. Its mil­i­tary code would be over­painted with unit mark­ings fol­low­ing de­liv­ery. One of the first Fw 190A-1s de­liv­ered to a front line unit – in this case 6./JG 26 at Moorsele, Bel­gium, in July 1941. Dur­ing its early days in front line ser­vice it was not un­com­mon to see a Fw 190 dowsed in foam af­ter an en­gine fire. It was only af­ter sev­eral months with the Luft­waffe that a so­lu­tion to the over­heat­ing prob­lem was fi­nally dis­cov­ered and mostly cured with a re-rout­ing of the ex­haust sys­tem.

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