Derivative: A long-nose derivative of Fw 190A (air-cooled) fitted with the liquid-cooled V-12 Jumo 213A-1 (“Dora”). Main intent of modifications: Adoption of an annular radiator to limit drag increase while concentrating structural changes mainly in the nose section. First flight: September 1942. Production & service: Mass production from Aug 1944 → frontline allocation in Nov → combat use from Dec. High-altitude suitability: Turbo-supercharger and cockpit pressurization ultimately not adopted. While it avoided the sharp high-altitude power drop seen on the A-series, the D-9 was fielded as a transitional high-speed fighter.

Engine: Jumo 213A-1 (liquid-cooled V-12) with MW50 (10 minutes continuous per use, 40 minutes total). Overall length: 8.95 m → 10.192 m (nose approx. +50 cm, rear fuselage approx. +49 cm). Empennage: Enlarged vertical tail (for stability). Intake: Supercharger intake protruding on the starboard nose. Cooling: Annular radiator mounted ahead of the engine. Pressurization: No pressurized cockpit in the final configuration. Turbo: No turbo-supercharger.

Handling: Roll performance decreased as the price for higher speed; however, pilot evaluations were generally favorable after familiarization. Fixed armament:

Nose: MG 131 13 mm × 2 (475 rpg)

Inboard wings: MG 151/20 20 mm × 2 (250 rpg) Protection: 12 mm armor plate behind the pilot / 50 mm armored windscreen in front. Ordnance: ETC501 / ETC504 centerline rack for bombs. Canopy: About 300 early aircraft retained the earlier canopy; later machines adopted the “Galland” blown canopy for better visibility. All-weather variant R11 (operational contribution: ○): canopy de-icing, FuG 125 radio navigation/landing guidance, LGWK 23 course indicator, PKS 12 autopilot. Other planned sub-variants saw little or no operational use.

(Notes) Figures vary by scope definitions (D-9 only vs. entire D-series; completed vs. accepted vs. operational). When citing, specify the coverage and basis of each number.

Background: Bombing of BMW plants depressed A-series output → D-9 brought forward into mass production. Combat: Entered combat by Dec 1944, but the Luftwaffe fighter arm suffered heavy losses during the “Wacht am Rhein” (Ardennes) offensive that month. Overall judgment: The airframe possessed credible potential against late-war Allied fighters, yet the lack of seasoned pilots and overwhelming material inferiority meant it could not alter the strategic picture. Designer’s view: For Kurt Tank, the D-series was a stopgap, with Ta 152 as the true objective. Anecdotally, voicing this view hurt unit morale.

Nohara & Shiwaku (1990); Nohara (2003): Emphasize aerodynamic refinement, the annular radiator’s advantages, and power superiority (approx. 1,750 hp for D-9 vs. ~1,450 hp for P-51), suggesting that in pure dogfight terms the D-9 could surpass the P-51. Rekishi-Gunzō (2010): While German sources rated the D-9 as comparable to the P-51D, much published data rely on estimated figures, and actual performance may have been slightly inferior to the latest Allied types.