Curtiss XP-60D - A Series of Misdirected Attempts to Get Things Right (II)

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Curtiss XP-60D (Model 90B)

   Hello everybody. Hello everybody. I’d like to introduce the Curtiss XP-60D as a potential addition to US aviation in War Thunder. The XP-60D was an evolution of the original XP-60 prototype, featuring an upgraded Merlin engine, a four-bladed propeller, and several minor design tweaks. Converted and completed between 1942 and 1943, this variant was part of Curtiss’ final efforts to develop a successor to the P-40 Warhawk. However, its story was cut short when it crashed in May 1943, marking the end of its brief history.


TL;DR:

An improved variant of the initial XP-60 prototype, closely resembling the P-40 Warhawk, featured an upgraded V-1650-3 Merlin engine and a four-bladed propeller.


History

Background

With the Curtiss P-40 Warhawk entering production by 1940, Curtiss began an ambitious effort to develop a superior aircraft that could replace the P-40. The US Army Air Corps (USAAC) was interested in supporting these efforts and awarded a contract to fund the development of potential successors.

Curtiss initially designed the XP-46 prototype, which shared similarities with the P-40, except it was built to be smaller and equipped with an inward-retracting undercarriage. The XP-46 took its first flight on February 15, 1941, but it offered no meaningful performance improvements over the P-40 and was outright rejected by the USAAC.

After the XP-46 did not secure production orders, Curtiss shifted focus to a new design: the Model 88, later designated the XP-53 by the Army. This model was intended to use a Continental XIV-1430-3 engine. However, engine development issues led to the cancellation of the XP-53 before it could be built.

Curtiss then moved on to the development of Model 90, which was designated XP-60. At the Army’s request, the XP-60 was initially designed to be powered by a Rolls-Royce Merlin engine and include laminar-flow wings, a type of airfoil designed to reduce drag and make the aircraft fly faster. Curtiss produced four airframes during this project, which resulted in nine different designations: XP-60, XP-60A, YP-60A, P-60A, XP-60B, XP-60C, XP-60D, XP-60E, and YP-60E. These versions represented Curtiss’ long and desperate attempts to develop a worthy successor to the P-40—efforts that lasted until late 1944.

XP-60D - Model 90B

In the summer of 1942, the original XP-60 prototype was returned to the Curtiss factory for upgrades, receiving a V-1650-3 Merlin engine equipped with a two-stage supercharger, the same engine that powered the P-51 Razorback Mustang. Rebuilt as the XP-60D, this version also featured a four-bladed propeller and minor design adjustments. Meanwhile, the A, B, and C variants of the XP-60 series had already been designated, each featuring its own powerplant.

Although sources disagree on whether the XP-60D was completed by August 1942 or sometime in early 1943, its external appearance changed little from the original XP-60. The design still resembled a P-40, albeit with revised landing gear and a modified tail section. The aircraft gained an additional 630 pounds, but it was projected to achieve a top speed of 390 mph.

The XP-60D’s service life was unfortunately cut short. On May 6, 1943, the aircraft crashed during a dive demonstration at Rome Air Depot, New York, when its tail section detached mid-flight. Of the XP-60 series, the XP-60D was the last variant to share significant design elements with the P-40 airframe, as later versions were built on entirely new platforms.


Specifications

Curtiss XP-60D (Model 90B)

General Characteristics

  • Crew: 1 (Pilot)
  • Length: 33 ft 7.5 in (10.23 m)
  • Height: 12 ft 4 in (3.75 m)
  • Span: 41 ft 5.25 in (12.62 m)
  • Wing Area: 275 sq ft (25.54 sq m)
  • Propeller Type: 4-bladed propeller
  • Propeller Diameter: 11 ft (3.35 m)
  • Powerplant: Packard/Rolls-Royce V-1650-3 Merlin liquid-cooled engine
    → 1,350 hp (993 kW)
  • Internal Fuel: 135 - 228 US gal. (511 - 863 L)
  • Empty Weight: 7,640 lb (3,465 kg)
  • Gross Weight: 9,947 lb (4,512 kg)

Performance

  • Power-to-Weight Ratio: 0.13 hp/lb (0.22 kW/kg)
  • Critical Altitude Speed: 390 mph @ 22,000 ft (627 km/h @ 6,706 m)
  • Wing Loading: 33.7 lb/sq ft (164.8 kg/sq m)
  • Average Initial Rate of Climb: 2,055 fpm
  • Service Ceiling: 29,000 ft (8,839 m)
  • Range: ~800 - 1,100 miles (~1,287 - 1,770 km)

Armament

  • Guns:
    • 6 to 8 x 0.50-cal. M2 Browning machine guns (250 rpg; 2,000 rounds)

Diagrams


Images


Conclusion | Why it should be in the game

   The addition of the Curtiss XP-60 series would bring an interesting variety of “what-could-have-beens” to US aviation in War Thunder, offering a potential successor to the P-40 Warhawk. The XP-60D represented an upgraded variant of the initial prototype but remained heavier while still armed with eight heavy machine guns. It was expected to match the speed of the P-40F and excel in Boom-and-Zoom tactics and head-on engagements.

   What makes the XP-60 series unique is its flawed but exhaustive development history—a series of prototypes that never fully evolved into a reliable fighter for the US Army Air Forces. Despite its potential, the XP-60 ultimately symbolized Curtiss’ final effort to secure production orders and replace the Warhawk during World War II, an ambition that unfortunately never came to fruition.


See Also - P-60 Family

XP-60 (Model 90A)

XP-60A (Model 95A)

XP-60C (Model 95C)

XP-60E (Model 95D)

YP-60E


Sources

  • Curtiss Aircraft 1907-1947 (1979)
  • The American Fighter The Definitive Guide to American Fighter Aircraft from 1917 to the Present (1987)
  • US Fighters of World War Two (1991)
  • America’s Hundred Thousand US Production Fighters of WWII (1997)
  • US Experimental & Prototype Aircraft Projects: Fighters 1939-1945 (2008)
  • Curtiss Company Profile 1907–1947 (2014)
  • Curtiss P-60
  • Curtiss P-60 - Wikipedia

Thank you for taking the time to read my suggestion! 😃

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Oh my, this gets a +1 just for it’s looks.

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Very happy radiator intake. :D

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