Focke Wulf Fw 190

Variants: D-Models

Fw 190D-9

The Fw 190 D (nicknamed the Dora; or Long-Nose Dora, "Langnasen-Dora") was intended to improve on the high-altitude performance of the A-series enough to make it useful against the American heavy bombers of the era. In the event, the D series was rarely used against the heavy-bomber raids, as the circumstances of the war in late 1944 meant that fighter-versus-fighter combat and ground attack missions took priority. A total of 1,805 D-9s were produced. Production started in August 1944.

With the D version the power plant was changed from the radial engine of earlier models to a 12-cylinder inverted-V liquid-cooled engine. The Jumo 213A generated 1,750 PS (1,726 hp, 1,287 kW), and could produce 2,100 PS (2,071 hp, 1,545 kW) of emergency power with MW 50 injection, improving performance to 686 km/h (426 mph) at 6,600 m (21,700 ft). In order to fit the new engine in the Fw 190 fuselage while maintaining proper balance, both the nose and the tail of the aircraft were lengthened, adding nearly 1.52 m (4.99 ft) to the fuselage, bringing the overall length to 10.192 m (33.438 ft) versus the 9.10 m (29.9 ft) of the late war A-9 series. The lengthened tail required a straight-sided bay, 30 cm (12 in) long, spliced in forward of the rear angled joint and tail assembly of the fuselage. To further aid balance, the pilot's oxygen bottles were moved aft and located in the new bay. This gave the rear fuselage a "stretched" appearance.

Furthermore, the move to a V12 engine from a radial engine required more components to be factored into the design, most significantly the need for coolant radiators (radial engines are air-cooled). To keep the design as simple and as aerodynamic as possible, Tank used an annular radiator (the AJA 180 L) installed at the front of the engine, similar to the configuration used in the Jumo powered versions of the Junkers Ju 88. The annular radiator with its adjustable cooling gills resembled a radial engine installation, although the row of six short exhausts stacks on either side of the elongated engine cowling showed that the Jumo 213 was an inverted vee-12 engine. While the first few Doras were fitted with the flat-top canopy, these were later replaced with the newer rounded top "blown" canopy first used on the A-8 model. With the canopy changes, the shoulder and head armor plating design was also changed. Some late model Doras were also fitted with the broader-chord Ta 152 vertical stabilizer and rudder, often called "Big Tails" by the Luftwaffe ground crews and pilots, as seen on W.Nr. 500647 Brown 4 from 7./JG 26 and W.Nr. 500645 Black 6 from JG 2. The centerline weapons rack was changed to an ETC 504 with a simplified and much smaller mounting and fairing.

Early D-9s reached service without the MW 50 installation, but in the meantime Junkers produced a kit to increase manifold pressure (Ladedrucksteigerungs-Rüstsatz) that increased engine output by 150 PS to 1,900 PS, and was effective up to 5,000 m (16,400 ft) altitude. It was fitted immediately to D-9s delivered to the units from September, or retrofitted in the field by TAM. By the end of December, all operational Doras, 183 in total, were converted. From November 1944, a simplified methanol water (MW 50) system (Oldenburg) was fitted, which boosted output to 2,100 PS. By the end of 1944, 60 were delivered with the simplified MW 50 system or were at the point of entering service. The 115 liter (30.4 US gal) capacity tank of the Oldenburg system would hold the MW 50 booster liquid, which was single purpose, while later systems were to be dual purpose, holding either MW 50 or additional fuel.

The fighter lacked the higher rate of roll of its close coupled radial-engined predecessor. However it was faster, with a maximum speed of 680 km/h (422 mph) at 6,600 meters (21,650 ft). Its 2,240 horsepower with methanol-water injection (MW 50) gave it an excellent acceleration in combat situations. It also climbed and dived more rapidly than the Fw 190A, and so proved well suited to the dive-and-zoom ambush tactics favored by the Schlageter fighter wing's pilots from November 1944 onward, when the wing converted to the Fw 190D. Many of the early models were not equipped with methanol tanks for the MW 50 boost system, which was in very short supply in any event. At low altitude, the top speed and acceleration of these examples were inferior to those of Allied fighters. Hans Hartigs recalled that only one of the first batch of Dora 9s received by the First Gruppe had methanol water injection, and the rest had a top speed of only 590 km/h (360 mph).

Owing to the failure of multiple attempts to create an effective next-generation 190, as well as the comments of some Luftwaffe pilots, expectations of the Dora project were low. These impressions were not helped by the fact that Tank made it very clear that he intended the D-9 to be a stopgap until the Ta 152 arrived. These negative opinions existed for some time until positive pilot feedback began arriving at Focke-Wulf and the Luftwaffe command structure. Sporting good handling and performance characteristics, the D-9 made an effective medium altitude, high speed interceptor, although its performance still fell away at altitudes above about 6,000 m (20,000 ft). When flown by capable pilots, the Fw 190D proved the equal of Allied types.

As it was used in the anti-fighter role, armament in the "D" was generally lighter compared to that of the earlier aircraft—usually the outer wing cannon were omitted so that the armament consisted of two 13 mm (.51 in) cowling-mounted MG 131s, with 400 rounds per gun, and two wing root mounted 20 mm MG 151/20E cannon with 250 rounds per gun; all four weapons were synchronized to fire through the propeller arc. The wings of the D-9 still had the electrical circuits and attachment points for the underwing BR 21 rocket propelled mortar, although none appeared to have used these operationally. While inferior to the A-series in roll rate, the "D" was superior in turn rate, climb, dive and horizontal speed. The Dora still featured the same wing as the A-8, however, and was capable of carrying outer wing cannon as well, as demonstrated by the D-11 variant, with a three-stage supercharger and four wing cannon (two MG 151s and two MK 108s). The first Fw 190 D-9s started entering service in September 1944, with III./JG 54. It was quickly followed by other units including I./JG 26 which flew its last operations on the A-8s on 19 November 1944.

Some Fw 190 Ds served as fighter cover for Messerschmitt Me 262 airfields, as the jet fighters were very vulnerable on take-off and landing. These special units were known as Platzsicherungstaffel (airfield security squadrons). One unit, known as the Würger-Staffel, was created in April 1945 by Lieutenant Heinz Sachsenberg at the behest of Adolf Galland, and was part of JV 44. The role of the Staffel was to guard the airfield and JV 44's Me 262s as they landed; as such the Fw 190s were supposed to take off before the jets and circle the airfield in pairs (a Rotte). However, to allow the 262s a clear run back to the airfield the 190s had to land before the jets, negating their protection. To help anti-aircraft artillery protecting the airfields to quickly identify friendly aircraft, the under-surfaces of the Würger-Staffel 190s were painted red with narrow white stripes. leading to the alternative nickname of Papageien Staffel (parrot squadron) from the bright red color.

Fw 190 D-11

17 Fw 190 D-11s were known to have been manufactured. This version was fitted with the updated Jumo 213F series engine similar to the Jumo 213E used in the Ta-152 H series but minus the intercooler. Visible changes over the D-9 were the enlarged supercharger air intake on the starboard side cowling and the use of a wooden, broad-bladed VS 9 or 10 propeller unit utilizing three 9-27012 C-1 blades with a diameter of 3.6 m (11.8 ft). The 13 mm (.51 in) fuselage guns were removed, and the cowling redesigned by omitting the gun troughs and simplifying to a flat profile. Two 30 mm (1.18 in) MK 108 cannons were installed in the outer wings to complement the 20 mm MG 151s in the inboard positions. Of the 17 Dora-11s delivered, three can be accounted for. One, the best known, was Rote 4 (red 4) of JV 44's Platzschutz unit. Another, white chevron, was found at München-Riem, and may have served with JV 44 after serving at the Verbandsführerschule General der Jagdflieger (Training School for Unit Leaders) at Bad Wörishofen; it is not known if it was actually used operationally. A third, white 61, was also found after the war at the Verbandsfuehrerschule General der Jagdflieger.

Fw 190 D-12

While the D-11 was under manufacture, work started on the Fw 190 D-12 and D-13 models. These were similar to the D-11, but featured a Motorkanone nose cannon firing through the propeller hub. The D-12 had the 30 mm (1.18 in) MK 108 cannon, while the D-13 was fitted with a 20 mm MG 151/20 cannon. There were three D-12 test aircraft built: V63, V64 and V65, but no production aircraft were built with the D-13 selected for production instead.

Fw 190 D-13

The Fw 190 D-13 started with the construction of two prototypes (W.Nr 732053 and W.Nr 7322054), and the 20 mm MG 151/20 cannon was found to be quite suited for the aircraft and was already well known to be effective against allied bombers, as well as an effective ground support weapon. Thus the Fw 190 D-13/Rüstsatz 11 (/R11) version was selected to enter production. The D-13/R11 was fitted with all-weather flying equipment including the PKS12 and K-23 systems for steering and autopilot. The FuG 125 radio system, known as Hermine was fitted to the aircraft, as well as a heated windscreen. Pilots reported that due to the large amounts of torque produced by the engine, they usually used the steering system during the takeoff run as it helped with the rudder movements. The D-13 also introduced a hydraulic boost system for the ailerons, which was later used on the Ta 152.