Long-nose Dora – the stop­gap

The Fw 190D se­ries

Aviation Classics - - CONTENTS -

The en­gine ex­per­i­ments car­ried out by Focke-wulf through­out 1942 and into 1943 am­ply demon­strated that the trou­ble­some BMW 801 had reached the lim­its of its po­ten­tial. With the Fw 190 now strug­gling to match new Al­lied types, ur­gent ac­tion was needed to se­cure a new pow­er­plant and cre­ate a suc­ces­sor to the orig­i­nal de­sign.

While the Fw 190 re­mained an ef­fec­tive fighter in 1943, it was clear to designer Kurt Tank that a re­place­ment would even­tu­ally be needed. To this end, he de­signed a new pi­s­to­nengined fighter that would em­body all the lessons that Focke-wulf had learned dur­ing the devel­op­ment of the Fw 190. The new fighter would be its re­place­ment. Sub­mit­ted to the RLM for ap­proval in April 1943, the project re­ceived the des­ig­na­tion Ta 153 – the ‘Ta’ re­plac­ing ‘Fw’ in hon­our of Tank’s role as one of Ger­many’s most im­por­tant air­craft de­sign­ers. The air­craft he had sub­mit­ted bore a strong su­per­fi­cial re­sem­blance to its pre­de­ces­sor but was in fact an en­tirely new air­frame that would, it was pro­posed, be pow­ered by a ver­sion of ei­ther the Daim­lerBenz DB 603 or the Junkers Jumo 213. Both en­gines were still in devel­op­ment but had al­ready been used to power Fw 190 air­frames in flight dur­ing the Fw 190B and C ex­per­i­ments. The RLM, how­ever, re­jected the pro­posal on the grounds that an air­craft built en­tirely out of new parts would cause too much dis­rup­tion to ex­ist­ing pro­duc­tion lines. Tank there­fore had the de­sign al­tered to in­cor­po­rate more Fw 190 parts, par­tic­u­larly the main fuse­lage, and the new de­sign was la­belled Ta 152 in May 1943. The Ta 152A and B stan­dard fighter de­signs, the only dif­fer­ence be­ing the en­gine fit­ted, were rapidly de­vel­oped and three Fw 190 air­frames were con­verted for ex­per­i­men­tal use to test the 152’s struc­ture, sys­tems and han­dling. In De­cem­ber 1943, with Messer­schmitt strug­gling to con­vert its Bf 109 into a high altitude fighter as ei­ther the Bf 109H or the Me 155, Tank pitched a high altitude ver­sion of his own, the Ta 152H. The RLM or­dered six pro­to­types but it was clear that th­ese would take some time to pre­pare. Dur­ing a meet­ing on Jan­uary 13-14, 1944, Tank pro­posed an in­terim so­lu­tion to the prob­lem of im­prov­ing the Fw 190 while the Ta 152 was read­ied for ser­vice. By now, prob­lems with the 1750hp in­verted V12 Jumo 213A en­gine were close to be­ing re­solved – what if it could be fit­ted to the lat­est ex­ist­ing Fw 190 air­frame, the A-8, with a min­i­mal num­ber of ad­di­tional changes to ac­com­mo­date it?

It was fur­ther ar­gued that hav­ing the op­tion of a sec­ond en­gine to power the Fw 190 would be ad­van­ta­geous if the sup­ply of BMW 801s was halted due to en­emy ac­tion, such as the de­struc­tion of BMW’S pro­duc­tion fa­cil­i­ties. The RLM ap­proved this pro­posal and work on the new fighter, un­der the Fw 190D des­ig­na­tion, be­gan. Ear­lier projects to try the Jumo 213 in the Fw 190 air­frame had al­ready been al­lo­cated the let­ter ‘D’ as Fw 190D-1 and Fw 190D-2, the dif­fer­ence be­ing that the lat­ter had a pres­surised cock­pit while the for­mer did not. But as time wore on and the Fw 190A8 en­tered ser­vice, plans for the A-9 were al­ready be­ing ad­vanced. There­fore, it was de­cided to skip over D-3 to D-8 and, since the new air­craft was be­ing de­vel­oped along­side the A-9, des­ig­nate it D-9. While the cen­tral idea of the D-9 was to re­tain as many A-9 com­po­nents as pos­si­ble, some changes were un­avoid­able to cope with the sheer size and par­tic­u­larly the length of the Jumo 213A-1. Avoid­ing un­favourable changes in the cen­tre of grav­ity meant the air­craft’s tail had to be elon­gated with a straight 0.5m sec­tion be­ing added to the fuse­lage ahead of the fin. In ad­di­tion, a larger fin was cre­ated by adding an­other sec­tion to its cen­tre. This had al­ready been tested as part of the Ta 152 pro­gramme. The weight of the en­gine meant some ex­tra strength­en­ing was needed for the fuse­lage around the en­gine mounts ahead of the cock­pit and big­ger wheels were added to the un­der­car­riage too. In many other re­spects – con­trol link­ages, un­der­car­riage legs and electrics, ra­dio equip­ment and wings – the D-9 was al­most iden­ti­cal to the A-8 and A-9.

Build­ing dora

The first D-9 pro­to­type was a mod­i­fied ver­sion of the Fw 190 V17 ma­chine, re­des­ig­nated V17/U1. This had pre­vi­ously been ear­marked for the Jumo 213 but fit­ted with the DB 603 for testing in­stead. Now this was stripped out and the Jumo type fi­nally in­stalled be­tween late April and early May 1944. It was flown for the first time on May 17 by Bern­hard Märschel from Focke-wulf’s Adel­heide plant to the com­pany testing air­field at Lan­gen­hagen. It was then flown to the RLM cen­tre at Rech­lin on June 6 and in­ten­sively tested from June 11 to July 6. The sec­ond D-9 pro­to­type was a con­verted A-8 fresh from the pro­duc­tion line, WNR. 170003, which be­came Fw 190 V53. It first flew on June 12, pow­ered by a Jumo 213 CV which had been ar­ranged to al­low a can­non bar­rel to pass be­tween its banks of cylin­ders, fir­ing through the pro­pel­ler hub. Other ar­ma­ment was MG 151s in both outer and in­ner wing po­si­tions plus two MG 131s over the en­gine. The third pro­to­type was an­other con­verted A-8, Fw 190 V54, which was used to test the D-9’s se­cret weapon – wa­ter-methanol in­jec­tion. Known as MW 50, this po­tent mix­ture of 50% methanol, 49.5% wa­ter and 0.5% anti-cor­ro­sives, could be di­rectly in­jected into the Jumo 213’s su­per­charger for pe­ri­ods up to 10 min­utes at a time. Adding it caused the Jumo’s power lev­els to soar dramatically. From a base­line 1750hp, it shot up to more than 2000hp – giv­ing a top speed of some 426mph. With­out MW 50, the D-9 could only man­age 360mph. Us­ing the cor­ro­sive methanol and stress­ing the en­gine in this way served to re­duce its life­span sig­nif­i­cantly but this was deemed an ac­cept­able trade-off. V54 was de­stroyed and V53 dam­aged dur­ing an Amer­i­can bomb­ing raid on Lan­gen­hagen on Au­gust 5, 1944, but de­sign work was al­ready well ad­vanced and the first pro­duc­tion Fw 190D-9, WNR. 210001, was

com­pleted at an­other Focke-wulf fa­cil­ity, So­rau in Sile­sia, in late Au­gust. It was armed with just two MG 151s, in the wing roots, and the two MG 131s over the nose. Prob­lems with the air­craft’s Jumo 213A-1 en­gine, how­ever, pre­vented fur­ther pro­duc­tion un­til mid-septem­ber when the sec­ond of­fi­cial D-9, WNR. 210002, was fin­ished. Slowly, bulk pro­duc­tion also be­gan at Focke-wulf’s large Cot­tbus fac­tory. This had been built in 1941 near the city of Cot­tbus on the far eastern fringe of Ger­many – to keep it as far away from Al­lied bombers as pos­si­ble. It was a lo­ca­tion that would later pose a se­ri­ous prob­lem but for now it was able to build D-9s in sig­nif­i­cant quan­ti­ties. The fol­low­ing month, two sub­con­trac­tors also be­gan se­ries pro­duc­tion – Ar­beit­ge­mein­schaft Roland (WFG) at Nor­den­ham and Fieseler at Kas­sel. Junkers and Siebel also pro­duced large com­po­nent parts for the type. It is un­known pre­cisely how many D-9s were built, since records are in­com­plete, but at least 670 are doc­u­mented and it is likely that more than twice that num­ber were ul­ti­mately pro­duced since there are no records for De­cem­ber 1944 nor the pe­riod from Fe­bru­ary 1945 to the end of the war. Four field up­grade packs were planned for the D-9. R1 added two MG 151s in the outer wing po­si­tions, R2 re­moved the MG 131s but fit­ted MK 108s in the outer wings, R6 was the usual pair of WGR 21 mor­tars slung be­neath the wings and R11 was a bad weather pack with au­topi­lot, heated wind­screen, emer­gency equip­ment and FUG 125 ra­dio bea­con.

Front line long-nose

The first D-9s to en­ter ser­vice did so with III./JG 54 in Septem­ber 1944, the unit hav­ing been with­drawn from the front line in midAu­gust to pre­pare for con­ver­sion. Part of the Gruppe, 12./JG 54, was sta­tioned at Ach­mer to pro­vide pro­tec­tion for the Messer­schmitt Me 262s of Kom­mando Nowotny. The jets were ex­tremely vul­ner­a­ble when com­ing in to land and the D-9s were tasked with keep­ing en­emy fighters away. Very few of the first D-9s to reach com­bat units had the MW 50 in­jec­tion equip­ment in­stalled due to sup­ply short­ages but Jumo man­u­fac­turer Junkers quickly de­vel­oped a kit that could in­crease man­i­fold pres­sure and boost en­gine out­put by 120hp to around 1870hp. This was rapidly fit­ted to all new D-9s from the end of Septem­ber or retro­fit­ted as a field in­stal­la­tion kit by the Junkers Tech­ni­cal Field Ser­vice (TAM). By the end of Oc­to­ber, the num­ber of D-9s be­ing op­er­ated by III./JG 54 had risen to 68 but only 53 had been con­verted us­ing the pres­sure kit. Just one of them had the MW 50 sys­tem in­stalled and con­ver­sion work was on­go­ing with the other 14. There were 183 Do­ras op­er­a­tional with III./JG 54, II./JG 26 and III./JG 26 by the end of De­cem­ber 1944 and TAM was strug­gling to cope with the de­mands of up­grad­ing those that needed it in the field – its staff com­plain­ing that the Gruppe were op­er­at­ing from air­fields with­out hang­ers, which made the job much more dif­fi­cult. Sixty more D-9s were about to en­ter ser­vice, how­ever, and th­ese all had MW 50 in­jec­tion in­stalled as stan­dard. New pro­pel­lers were also added to the Do­ras in ser­vice be­fore the end of the year, which re­port­edly im­proved ef­fi­ciency by 15%. All of this meant that the D-9s in ser­vice could have widely vary­ing per­for­mance, depend­ing on the up­grades they had or had not yet re­ceived at the time. Dur­ing early 1945, a num­ber of other units be­gan con­vert­ing to the Fw 190D-9, in­clud­ing el­e­ments of JG 2, JG 3, JG 6, JG 51 and JG 301. Ober­leut­nant Oskar-wal­ter Romm, com­man­der of 15./JG 3 in Jan­uary 1945 said: “I was very keen to get hold of the Fw 190D-9. I suc­ceeded in get­ting one full Staffel equipped with this ver­sion, as well as my Gruppe Stab with four of th­ese air­craft plus one re­serve. “To get some of the air­craft we had to res­cue them from air­fields about to be over­run by the en­emy, in spite of the risks in­volved. “As an air su­pe­ri­or­ity and in­ter­cep­tor fighter, the Dora-9 han­dled bet­ter than the Fw 190A. It was faster and had a su­pe­rior rate of climb. Dur­ing dog­fights at al­ti­tudes of be­tween 3000m and 7500m (10,000-24,000ft), usual when en­gag­ing the Rus­sians, I found that I could pull the Fw 190D into a tight turn and still re­tain my speed ad­van­tage. “In the Fw 190A I had flown pre­vi­ously, dur­ing dog­fights I had of­ten to re­duce to min­i­mum fly­ing speed in the turn. In the de­scent the Dora-9 picked up speed much more rapidly than the Fw 190A, in the dive it could leave the Rus­sian Yak-3 and Yak-9 fighters stand­ing.” Leut­nant Karl-heinz Ossenkopf, of JG 26, said: “The Fw 190D-9 was quickly adopted by the pi­lots, af­ter some ini­tial reser­va­tions. They felt that it was equal to or bet­ter than the equip­ment of the op­po­si­tion. Its ser­vice­abil­ity was not so good, ow­ing to the cir­cum­stances. “I felt that the air­craft built at So­rau had the best fit and fin­ish. They could be recog­nised by their dark green cam­ou­flage. I hit 370mph with my own air­craft, Black 8, with full power and MW 50 methanol in­jec­tion, clean, 20-30m above the ground.” Once the D-9 had proven its worth in com­bat, and pro­duc­tion lines had been firmly es­tab­lished, there was nat­u­rally pres­sure to im­prove this hastily con­ceived stop­gap de­sign, even while devel­op­ment work on the Ta 152 con­tin­ued.

Do­ras in wait­ing

First up was an im­prove­ment to the Dora’s ar­ma­ment un­der the des­ig­na­tion Fw 190D-10. The plan was to re­move the two MG 131’s above the en­gine and re­place them with a sin­gle MG 151 mounted asym­met­ri­cally on the star­board side of the va­cated space. It had been hoped that an MK 108 could also be in­stalled fir­ing through the spin­ner but this could not be made to work with the

Jumo 213A so even­tu­ally the D-10 was scrapped with­out be­com­ing any­thing more than a pro­posal. A sec­ond at­tempt to im­prove ar­ma­ment was tied in with a change of en­gine to the Jumo 213F. The nose-mounted MG 131s were again deleted but their po­si­tion now sim­ply faired over with a smooth plate. The wing-root MG 151s were joined in­stead by a pair of MK 108 30mm can­non in the outer wing po­si­tions. Where the D-10 project sank leav­ing barely a trace, the D-11 made it to the pro­to­type stage, with a to­tal of seven be­ing pro­duced – Fw 190 V55-61. Th­ese were fol­lowed by at least 17 full pro­duc­tion D-11s dur­ing March 1945. More may have joined them in April but the fig­ures are miss­ing. Like the D-9, four Rüst­satz field mod­i­fi­ca­tion packs were to be of­fered, although it’s un­likely any of them ever were. D-11/R5 was to get an ad­di­tional 130 litre fuel tank in the fuse­lage and four un­pro­tected fuel bags in the wings. D-11/R11 was the bad weather pack as de­tailed for the D-9, R20 was to get the new and im­proved Jumo 213F-1 en­gine, and R21 was all the kit from R11 with the en­gine from R20. One sig­nif­i­cant prob­lem with the D-11 soon be­came ap­par­ent how­ever. Ger­many had been re­liant on low grade syn­thetic rub­ber for its air­craft tyres for sev­eral years and this be­gan to cause dif­fi­cul­ties when the weight of air­craft be­gan to creep up. The heavy Jumo 213F en­gine com­bined with the D-11’s heavy ar­ma­ment over­loaded its 700 x 175mm tyres. There­fore it was nec­es­sary to come up with ver­sions of the D-9 with only slightly heav­ier ar­ma­ment – the D-12 and D-13. The for­mer had a sin­gle en­gine-mounted MK 108 plus its MG 151s, while the lat­ter had a third MG 151 fir­ing through its pro­pel­ler. Again, th­ese reached the pro­to­type stage, with V62, V63 and V64 testing the D-12 lay­out and V65 and V71 do­ing the same for the D-13. There were yet more Rüst­satz con­ver­sions in the off­ing too. Fw 190D-12/R5 and D-13/R5 were to fea­ture the same ad­di­tional fuel tanks as the D-11/R5. The D-12/R11 and D-13/R11, rather than be­ing sim­ple field mod­i­fi­ca­tion packs, were in­tended to leave the fac­tory with all the R11 bad weather fighter fea­tures from the D-9/R11 fit­ted. It was pro­posed that both of th­ese types would en­ter pro­duc­tion in March 1945, the for­mer at Arado and Fieseler, and the lat­ter at Ar­beit­ge­mein­schaft Roland. Then there were to be R14, R21 and R25 packs for both types. R14 would have turned the air­craft into a tor­pedo car­rier with the ap­pro­pri­ate fit­tings and sys­tems, R21 was the same as the D-11/R21 and R25 would have in­volved the in­stal­la­tion of the up­com­ing 1880hp Jumo 213 EB pow­er­plant. With methanol-wa­ter in­jec­tion, this en­gine was ex­pected to de­velop a huge 2250hp, push­ing the D-12 or D-13’s top speed up to 478mph at 31,000ft.

The last Do­ras

Even though Focke-wulf had pre­vi­ously been told to cease work on a Daim­ler-benz DB 603 pow­ered Fw 190 in Jan­uary 1943, by the end of the sum­mer of 1944, the 1750hp en­gine had fi­nally been de­vel­oped to a point where it was both pow­er­ful and re­li­able. It was also be­com­ing avail­able, as Daim­ler-benz got se­ries pro­duc­tion un­der way. Focke-wulf, along with Ger­many’s other ma­jor air­craft man­u­fac­tur­ers, was in­formed that the DB 603 was now an op­tion for its lat­est de­signs and pro­pos­als were quickly drawn up to in­cor­po­rate it into both the Ta 152 and Fw 190D pro­grammes. For the Dora, it was pro­posed that the D-12 de­sign, it­self still un­der devel­op­ment, could be mod­i­fied to ac­cept the DB 603 as the D-14. De­vel­op­ing a pro­to­type for the D-14 was a prob­lem how­ever, since the D-12 had not yet en­tered pro­duc­tion. There­fore, a pair of D-9s were taken from the pro­duc­tion line and al­tered to be­come Fw 190 V76 and V77, the lat­ter ini­tially re­tain­ing its Jumo 213 en­gine. V76 made its first flight on Novem­ber 20, 1944, with a Daim­ler-benz test pi­lot at the con­trols and was then flown against V77 to see how the en­gine per­formed against the Jumo-pow­ered type. At all al­ti­tudes, it was found that the Daim­lerBenz of­fered greater speed. On Jan­uary 31, 1945, how­ever, the D-14 pro­gramme was can­celled so that it would not serve to de­lay the start of Fw 190D-12 pro­duc­tion. In­stead how­ever, Focke-wulf was told that it should cre­ate a new vari­ant, the Fw 190D-15. This was to be a very ba­sic con­ver­sion of ex­ist­ing Fw 190A-8 or F-8 air­craft with the ad­di­tion of the DB 603 and the fuse­lage ex­ten­sions of the D-9 for bal­ance. It is pos­si­ble that a sin­gle pro­to­type was com­pleted but the war ended be­fore work could re­ally begin on the D-15, which was to be the fi­nal devel­op­ment of the Fw 190D.

Edi­tor’s col­lec­tion

Lack­ing the grime of win­ter com­monly seen on Fw 190D-9s – since al­most all of their in-ser­vice ca­reer took place dur­ing the win­ter of 1944-45 – this ex­am­ple has just rolled off the pro­duc­tion line at Bre­men-neuen­lan­der­feld. WNR. 210051 was later de­liv­ered to III./JG 54.

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

An early pro­duc­tion Fw 190D-9 stands out in the snow prior to de­liv­ery to III./JG 54, the first unit to op­er­ate the type, in Septem­ber 1944. Fw 190D-9 WNR. 500570 ‘Blue 12’ is be­lieved to have served with 8./JG 6 be­fore be­ing sur­ren­dered to Amer­i­can forces at Fürth-artzen­hof air­field near Nurem­berg. Note the P-47s glint­ing in the sun in the back­ground. A pair of Fw 190D-9s be­long­ing to II./JG 26 taxi along wooden deck­ing cov­er­ing the muddy run­way at Nord­horn-klausheide in Fe­bru­ary 1945.The up­ward an­gle of the D-9’s enor­mous nose made ma­noeu­vring on the ground dif­fi­cult.

Edi­tor’s col­lec­tion Edi­tor’s col­lec­tion

A pair of Fw 190D-9s from 7./JG 26 op­er­at­ing from hid­den po­si­tions in wood­land near Nord­horn-klausheide air­field in Lower-sax­ony dur­ing Fe­bru­ary 1945. Ground crew hard at work on a care­fully cam­ou­flaged Fw 190D-9 of JG 26 at Fürste­nau dur­ing Fe­bru­ary 1945. Ser­vice­abil­ity was a se­ri­ous prob­lem for the ad­vanced D-9 as it was usu­ally re­quired to op­er­ate in less than ideal con­di­tions.

Edi­tor’s col­lec­tion Edi­tor’s col­lec­tion Edi­tor’s col­lec­tion Chris Sand­ham-bai­ley

The Fw 190D-9 of Ober­stleut­nant Ger­hard Michal­ski, of Stab./jg 4, at Frank­furt in 1945. An Fw 190D-9 of Grup­pen­stab II./JG 6 as it was sur­ren­dered to Amer­i­can forces, the 10th Photo Re­con­nais­sance Group in Bavaria on May 8, 1945. The sec­ond pro­to­type for the D-11 se­ries,v56, was the sec­ond of seven be­fore full scale pro­duc­tion be­gan.this did not last long, how­ever, as fac­to­ries sup­ply­ing es­sen­tial com­po­nents were soon over­run. ‘Yel­low 10’ is the only sur­viv­ing Fw 190D-13 and is on dis­play in Seat­tle, Wash­ing­ton, USA, to­day.

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