Long-nose Dora – the stopgap
The Fw 190D series
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.
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.
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.
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.
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.
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.