High altitude failure – Fw 190B and C
Fw 190B and C
The Fw 190A boasted superior performance at low and medium altitudes when it first entered service, but above about 20,000ft it began to struggle. This was no cause for concern until it became clear that the RAF was developing high altitude bomber and reconnaissance aircraft that could cruise well out of its reach. So began protracted attempts to produce a high-flying interceptor Fw 190.
Intelligence about British high-altitude prototypes began to reach the RLM in early 1942 and by late spring it had become a source of considerable concern. As a result, the ministry called a meeting at the Messerschmitt facility in Augsburg on May 20 and invited representatives of FockeWulf along. Here it outlined a requirement for a new Höhenjäger – a fighter capable of achieving air superiority at high altitude. Afterwards, Willy Messerschmitt and his team started work on adapting the most advanced development of the Bf 109 available – the Me 209 – into a machine that could fulfil both this requirement and another to produce a new naval fighter for the Graf von Zeppelin aircraft carrier which was then still under construction. This became the Me 155, with the high altitude variant being the Me 155B. It was designed, initially, to share many components with the Bf 109G but had a wide track undercarriage, a new engine and much longer wings. Kurt Tank decided to investigate three potential solutions as part of wider efforts to improve the Fw 190’s performance – mostly centred on its powerplant. Firstly, he had his team look at ways of boosting the performance of the standard BMW 801 powered Fw 190. Secondly, the Fw 190 would be experimentally fitted with a turbosupercharged version of the liquidcooled inline Daimler-benz DB 603 engine. Work on this idea had already been under way since March 1941. Thirdly, a Fw 190 fitted with a Jumo 213 engine would be tried. This too was already under consideration, although it was deemed unlikely to surpass the performance potential of the other two should they prove successful. The first line of enquiry quickly resulted in the Fw 190A-3/U7. The aircraft’s BMW 801 D2 had its Kommandogerät management system removed to allow finer manual control at high altitude, larger air intakes protruded from the engine cowling either side of it and it also had adjustable cooling flaps. Armament was reduced to just two MG 151 cannon in the wing roots to save weight. A trio of prototypes were built and the first flew on August 16, 1942. Tests demonstrated only a small performance advantage over the standard A-3, in the order of 5-6mph at altitude. It had been planned to fit a turbosupercharger but the only models available at the time sat directly behind the engine and would have exhausted directly in front of the Fw 190’s cockpit. A different tack was needed and it was therefore decided to add longer wings to a standard A-3 instead, plus the pressurised cabin and GM-1 nitrous injection for the engine. This was to become the Fw 190B. Wingspan was duly enlarged from 34ft 5¼in to 40ft 8¼in on Fw 190 V12 but work on this was halted and a quartet of A-0s were converted instead as Fw 190B-0s. The first Fw 190B-0 was used to begin pressure cabin tests. These proved problematic because the glazing on the cabin, which was supposed to be a uniform 6mm thick, proved to be 4.4-5.3mm thick instead – causing it to blow out under relatively low pressurisation. Further problems followed and it wasn’t until January 9, 1943, that a successful flight test took place with standard sized wing. More testing revealed that the glazing was ineffective at keeping the cold out, so a double-glazed version was developed that was heated using warm air from the engine. The first Fw 190B-0 was then fitted with the new lengthened wing and tests continued into June. The standard wing was then refitted in October. Meanwhile, the second Fw 190B-0 had begun flight testing in March with the new double-glazed canopy and a different armament configuration – a pair of MG 17s over the nose joining the two wing root mounted MG 151s. While the guns caused no problems, the double glazed canopy was found to suffer from excessive condensation, limiting visibility. The third B-0 was ready to go by early April. It first flew on April 6 with the double glazed canopy, MG FF cannon in the outer wing positions and a new heater designed to prevent the formation of ice on the cockpit at high altitudes. The fourth B-0 was used to test the installation of GM-1 equipment to boost engine power and had a 115 litre tank of nitrous oxide fitted behind the pilot. Before these tests were even begun, back in January 1943, it was envisaged that a series of six Fw 190B-1 production aircraft would be produced but this idea was dropped during the summer since the programme was showing little promise of meeting the RLM’S requirement. Only a single Fw 190B-1 was built and did not fly until January 21, 1944.
FW 190C AND THE HIRTH TK 11
Efforts to produce Fw 190s powered by DB 603 and Jumo 213 engines were collectively given the Fw 190C designation. The DB 603 had been under development at Daimler-benz since 1936 and proposals to fit it to the Fw 190 dated back to March 21, 1941 – 14 months before the RLM called Focke-wulf to its meeting at Augsburg. The protracted development of the engine continued, however, and the first flight of the Fw 190 V13 testbed did not take place until February 1942. Test pilot Hans Sander, who flew it, was unhappy with the engine’s throttle and its cooling system. Further testing was carried out and a second aircraft, V15, had joined the programme by the time the May 21 meeting took place. The Focke-wulf representatives meeting with the RLM must therefore have felt fairly confident that they already had the winning submission to the contest in hand. However, engine problems persisted and work on testing the Jumo 213 had not yet begun – since that engine was similarly mired in development difficulties. It had been planned to fit Fw 190 V17 and V18 with the Jumo 213 but by July 1942, after the RLM decided to remove V15 and the similar V16 from Focke-wulf and send them for testing at Rechlin, it was decided to fit them with DB 603s instead so in-house testing could continue. Plans were drawn up to create two production versions of the DB 603 Fw 190 – the C-1 and C-2. The former would have an unpressurised cockpit and an armament of two MG 131s on its nose and two MG 151s in the wing roots. The latter would get a pressurised cabin and an engine-mounted MG 151, MK 103 or MK 108 firing through the spinner. In August 1942, a further development of the DB 603 powered Fw 190 was proposed, this time with the addition of an underslung Hirth TK 11 turbosupercharger. This was expected to result in an aircraft with 2000hp. It would also get larger wings and a pressurised cabin. The modifications were made to Fw 190 V18, now fitted with its DB 603, which was redesignated Fw 190 V18/U1. It first made two short flights on December 20, 1942, and test pilot Sander reported: “In the static test, there were no particular difficulties. The engine runs very smoothly and quietly, but the coolant temperature level is significantly higher than the engine without a turbosupercharger. “Even at 1700rpm the average temperature is still over 122ºc. While parked, steam rises from the aircraft and there is some water loss. The flights were short due to bad weather and a strong tendency for the aircraft to overheat. “Flying characteristics were not observed, but the aircraft is very tail heavy. After takeoff, low engine power is noticeable (lack of boost pressure, and pre-warmed air).” Other modifications to V18/U1 included a significantly enlarged tailfin, similar to that later fitted to the Ta 152, and a large VDM four-bladed propeller. Hirth experienced serious and ongoing difficulties in developing its turbosuperchargers owing to a critical shortage of raw materials to produce sufficiently heat-resistant alloys. The US, however, had no such problem and made turbosuperchargers a feature of aircraft such as the P-47 Thunderbolt. An order for 727 Fw 190Cs was placed by the RLM in December 1942 but on January 26, 1943, this was cancelled and Focke-wulf was told to cease development of the DB 603powered versions and concentrate on making the Jumo 213 work instead. This decision would result in the development of the Fw 190D which is covered in more detail elsewhere.
The company persisted with its testing of V18/U1 however, and by May 1943 it was able to achieve a very respectable 416mph at 36,100ft using its turbosupercharger. With this switched off, however, performance was diminished to 385mph at 31,150ft. Still, these results were enough to warrant another five being fitted with the Hirth TK 11. The first of these was Fw 190 V29, which was fitted with a DB 603 S unit and sent to Hirth in June for use as a static turbosupercharger development airframe. V30 got a further development of the DB 603, the S-1, and first flew on October 22, 1943. Further test flights followed. V31, meanwhile, was written off almost immediately after it overturned on landing following its first flight. V32 was completed in November 1943 and was also powered by a DB 603 S-1. It served as an armament testbed, being fitted with two MG 151s in the wing roots. V33 arrived too late, however, because by this time all remaining Hirth turbosupercharger test aircraft were being converted for use in another development programme that would result in Fock-wulfe’s Fw 190 successor – the Ta 152.
Oberstleutnant Hannes Trautloft flew this Fw 190A-4 with Stab/jg 54 from Staraya Russa in the USSR during April 1942.Trautloft had already had a lengthy and distinguished career as a fighter pilot by then, having joined the Deutsche Verkehrsfliegerschule at Schleissheim in 1931, aged 19, and undergone secret military training, ironically in the USSR, the following year. He later fought on the side of Franco’s nationalists during the Spanish Civil War, flying Heinkel He 51s, and together with fellow pilot Kraft Eberhardt, scored the first German victories of the conflict – each of them shooting down a Breguet XIX on August 25, 1936. When the first Bf 109 prototypes were delivered to the nationalists, Trautloft flew them and helped to develop the aerial tactics that saw the type go on to huge success during the Second World War. He fought during the invasion of Poland, and the Battle of Britain, and became the Kommodore of JG 54 on August 24, 1940 – a post he still held by April 1943. His 58th and final victory of the war had been over an Ilyushin Il-2 the previous month – his ninth Sturmovik kill. His front line career ended on July 6, 1943, when he was appointed Inspizient Ost with the General der Jagdflieger’s office.
The Fw 190A-6 of Leutnant Heinz-günther Lück, flying with 1./JG 1 from Deelen, Holland, in September 1943. Lück scored just six victories but every single one of them was a Boeing B-17 bomber. He destroyed his first Flying Fortress on July 26, 1943. Further claimed ‘kills’ followed on July 30, August 19, October 8 and November 26. He was injured in a motorcycle accident at Deelen on November 30, 1943, but is still credited with another victory on January 5, 1944. It seems that one of these claims was rejected, however, since his final tally stood at five. He was appointed as Staffelkapitän of 1./JG 1 on January 24 and continued in the post until he was wounded in action on April 9. His Fw 190A-8 was damaged in combat with American bombers in poor weather and he crashed on the Danish island of Aeroe. He never flew again and was assigned to various staff positions.
The enormous Hirth TK 11 turbosupercharger unit fitted beneath this experimental Fw 190 airframe,v18/u1, eventually gave the aircraft a more than acceptable top speed of 416mph at 36,100ft but it couldn’t be run constantly. Eventually the programme was superseded by the Fw 190D and Ta 152.
A side view of Fw 190 V13 prominently displays the lengthened nose needed to house its DB 603 engine.v13 was written off after five months due to crash damage sustained on July 30, 1942. A close up view of the DB 603 as fitted to Fw 190 V13.the engine had been in development for more than six years by this point and was far from ready for full scale production. Fitted with an early DB 603 A-0 engine, Fw 190 V13 required a large intake beneath the engine cowling for its oil cooler.the aircraft first flew in February 1942.
Fw 190 V15 was used to test the extremely long exhaust pipes later fitted to V18/U1. The V16 experimental airframe, fitted with the DB 603 and similar to V15 but without the long exhausts, was used for tests by Daimler-benz itself at Stuttgart-echterdingen during the latter part of 1942. Focke-wulf’s first effort at a high-altitude interceptor version of the Fw 190 was the A-3/U7.THE Kommandogerät management system was removed from its BMW 801 D-2 and it had large external air intakes fitted.three were built but performance was disappointing. A forward view of Fw 190 V16. It was intended that the aircraft would be fitted with a motorkanone, possibly a MK 103 or MK 108, firing through the centre of the hollow propeller hub. The DB 603 as fitted to V16.the engine never saw active service with a FockeWulf aircraft but did power the Heinkel He 219, Dornier Do 335, Messerschmitt Me 410 and Focke-wulf Ta 152C – the last of which arrived too late to be flown against the Allies.
From the front, the huge groundskimming Hirth supercharger housing of Fw 190 V18/U1 is even more evident. The lengthy exhaust of Fw 190 V18/U1 required a faired-in housing all the way down the side of the aircraft’s fuselage. Fw 190 V18/U1 was never given a full paint job and retained its natural metal finish throughout testing. Despite its turbosupercharger-enhanced performance, it was still too unreliable for full production and the design was dropped in favour of more promising types.