Focke-Wulf Fw 190 D-9

From the Fw 190's inception Focke-Wulf sought better high-altitude performance, where the BMW 801 of the A series fell off. After the turbocharged B series and the Daimler-Benz DB 603-powered C series, the choice fell on the Junkers Jumo 213, a supercharged inverted-V 12-cylinder engine previously used only in bombers. According to HistoryOfWar, the D series began in late 1943 when several Fw 190 A-7s were converted into D-0 prototypes with the Jumo 213 A; the English and German Wikipedia articles date the completion of the first D-0 prototype to October 1942, and the National Air and Space Museum (NASM) says prototype testing began in March 1942.

The longer engine meant a nose extended by about 0.6 m and, to keep the centre of gravity, a plug of about 0.5 m in the rear fuselage ahead of the tail; the fin was enlarged as well. Hence the "long-nose" label that both Allied and Luftwaffe pilots immediately gave it. The Jumo 213 A had an annular radiator just behind the propeller spinner, so the nose still resembled a radial cowling.

According to the NASM, the first production variant was designated D-9 because the previous production type was the A-8. After small batches of D-0 and D-1 pre-production fighters had been delivered for service evaluation in spring and summer 1943, series construction started in summer 1944 at Marz, Cottbus and Kassel-Waldau, part of the major expansion of single-engined fighter output driven by Erhard Milch. The German Wikipedia dates the start of the D-9 fighter version to September 1944.

The Jumo 213 A-1 was rated at 1776 hp according to the NASM and HistoryOfWar (1750 PS take-off power per the German Wikipedia). Early D-9s reached the units without the MW 50 water-methanol system; Junkers developed a kit that raised boost pressure and took output to about 1900 PS up to 5000 m. The kit was factory-fitted to all D-9s built from September 1944 and retrofitted in field workshops to earlier ones, so that by December 1944 all 183 D-9s in service had it. From November 1944 a simplified MW 50 system was fitted at the factory, raising emergency power to 2100 PS; the NASM and HistoryOfWar give 2240 hp with water-methanol injection.

Because the D-9 was intended mainly to fight escort fighters at altitude, its armament was cut for weight to two 13 mm MG 131 machine guns above the engine and two 20 mm MG 151/20 E cannon in the wing roots; the NASM gives 250 rounds per cannon and 475 per machine gun. The wing was the same as the A-8's, with fittings for outer-wing guns, but these were not used on the D-9. The ventral rack was replaced by the simpler, lower-drag ETC 504, and each wing could carry a 300-litre drop tank or a 250 kg bomb. Later aircraft received the bubble canopy, and photographs show D-9s with R4M rocket rails under the wings. Some late-batch aircraft had the broader fin and rudder of the Ta 152, such as "Brown 4" of 7./JG 26 (W.Nr. 500647) and "Black 6" of JG 2 (W.Nr. 500645).

According to HistoryOfWar, the D-9 reached 685 km/h at 6600 m, had a service ceiling of 12000 m, a maximum range of 835 km, an empty weight of 3490 kg and a maximum take-off weight of 4840 kg.

The German Wikipedia states that 366 D-9s had been built by 30 November 1944 (252 of them by Focke-Wulf in Bremen, 41 by Fieseler in Kassel and 35 by MiMetall in Erfurt) and that a further 1056 were produced between 1 December 1944 and the end of March 1945, 117 of them with the R11 bad-weather kit (Rüstsatz R11) and 35 with the EZ 42 gunsight: 1422 D-9s in total. The NASM, by contrast, says that between 650 and 700 Fw 190 Ds were completed, and that Focke-Wulf's Marienburg plant was producing eight Fw 190 Ds a day in December 1944. The figures do not agree and both are given here.

According to the German Wikipedia, the first D-9s entered service in September 1944 with III./JG 54; the NASM gives October 1944 for the same unit. They were followed by I./JG 26, which began converting from the A-8 to the D-9 on 16 November 1944, by II./JG 26 and, in early 1945, by JG 2 and JG 301. On its first operational mission with the D-9, II./JG 26 shot down four Lancaster bombers and one Mosquito for the loss of one aircraft, according to the NASM.

Pilots were initially wary of an engine designed for bombers, fearing sluggish throttle response in combat, but experience convinced them the D-9 was a match for Allied fighters. Its roll rate was lower than that of the radial-engined versions, but climb rate, level top speed and altitude performance were clearly better. Kurt Tank, Focke-Wulf's chief designer, nevertheless regarded it only as a stopgap until the Ta 152, which was itself based on this model.

Although conceived as a high-altitude fighter, the D-9 was rarely used against heavy-bomber raids, since by late 1944 fighter-versus-fighter combat and ground attack took priority. D-9 units including JG 2 and JG 26 took part in Operation Bodenplatte on 1 January 1945, in which JG 2 suffered 40 percent losses. By the time JG 6 received 150 D-9s in April 1945, fuel shortages meant only four aircraft could fly at a time. Oberleutnant Hans Dortenmann claimed 18 aerial victories in the D-9, the best score by any pilot on the type.

The Soviet Baltic Fleet air arm operated a number of D-9s captured in East Prussia, including two taken intact by the 2nd Guards IAP at a Focke-Wulf facility near Marienburg; according to the NASM they served until 1947 or 1948. A Soviet post-war assessment found the Lavochkin La-5 superior in a mock dogfight, while praising the D-9's windshield, gunsights, electrical equipment and stability as a gun platform.

The NASM's D-9, Werknummer 601088, was probably built at the Bernburg plant and carries the markings of a staff officer of IV.(Sturm)/JG 3 "Udet". In June 1945 it was one of 21 German aircraft gathered by Air Materiel Command intelligence officers and flown from Flensburg to Cherbourg for shipment to the United States. With test registration FE-120 it was flight tested by the Air Materiel Command at Wright Field, with a performance report issued in September 1946 by 1st Lt. Charles A. Ross. The USAF donated it to the NASM on 15 June 1960, and it has been on loan to the USAF Museum at Wright-Patterson since 1975. In Germany, the Military History Museum at Berlin-Gatow displays the only known D-9/R11, W.Nr. 210968, recovered from Lake Schwerin in 1990; its number range points to early production at Sorau.