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Curtiss XP-40Q (Warhawk)

United States (1943)
Picture of Curtiss XP-40Q (Warhawk) Single-Seat Monoplane Fighter Prototype Aircraft

The Curtiss XP-40Q became the fastest of the Warhawk fighter line but still could not match the capabilities of competitors during World War 2.

Detailing the development and operational history of the Curtiss XP-40Q (Warhawk) Single-Seat Monoplane Fighter Prototype Aircraft.  Entry last updated on 7/13/2018. Authored by Staff Writer. Content ©

As important as the Curtiss P-40 Warhawk fighter series was to the Allied cause in the early-going of World War 2 (1939-1945), it nonetheless held roots in the pre-war period. As such, it was quickly becoming outpaced by more modern wartime developments that were driven by practical combat experience. Curtiss attempted several programs to evolve their P-40 product along but all failed in the end. The XP-40Q was one such attempt and this work was intended as an ultimate incarnation of the P-40 but it, too, failed to see adoption as it was still an outmoded design when compared to contemporaries like the Republic P-47 Thunderbolt and North American P-51 Mustang fighters.

The XP-40Q began in offshoot projects like the Model 87X and the XP-40N of 1943 and each incorporated several modern changes to keep the machine a viable gunnery platform for the foreseeable future. The Model 87X evolved to become the XP-40Q and this endeavor involved a pair of P-40K airframes and a single P-40N.

The first P-40K aircraft was outfitted with an Allison V-1710-121 rated at 1,425 horsepower output and held its cooling intakes at the wings. The engine cowling was redesigned as a much closer-fitting cover to encourage aerodynamic efficiency. All other qualities of the fighter were still rooted in the original P-40 which only worked against the design. This prototype was designated simply as "XP-40Q".

The second P-40K had the cooling intakes replaced by a more traditional, small-area chin scoop and was completed with a more useful bubble-style canopy. The bubble canopy allowed the rear dorsal section of the fuselage to be cut-down for streamlining and as a weight-savings measure. A section of bulletproof glass was mounted inside the curved windscreen for pilot protection. The supercharged engine featured water injection for additional war power output and drove a four-bladed propeller unit over the original's three-bladed unit. This prototype became "XP-40Q-1" in the lineup.

Then followed the third prototype - "XP-40Q-2" - whose only major feature was clipped wing tips to add a slight bump in speed. This quality was also later added to the first prototype.

With the changes in place, the Q-series became the fastest Warhawks of the Curtiss family of fighters, netting speeds over 420 miles per hour (422 mph officially). Earlier marks did not even exceed 400mph. However, this was not enough to compete with the numbers of P-47 and P-51 fighters coming off production lines and were more than ready to tackle a variety of over-battlefield roles. This inevitably led the Q-series to find its end before 1945.

In the post-war period, two prototypes were scrapped. XP-40Q-1 found a slightly extended life as it was purchased for competition flying in the Cleveland Air Races. During the 1947 Thompson Trophy Race, its engine caught fire and the pilot baled - the aircraft becoming a total loss as it crashed in flames.

As finalized, the XP-40Q showcased a wingspan of 35.2 feet and a length of 35.3 feet. It's loaded weight was 9,000lb. Maximum speed was 422 miles per hour with a service ceiling of 39,000 feet. Power stemmed from a single Allison V-1710-121 outputting 1,425 horsepower. The design was never outfitted with armament - its suite proposed as 4 x 0.50 caliber Browning heavy machine guns. This was another limiting weight-savings measure that ultimately would have lacked the punch of its competitors.

Any available statistics for the Curtiss XP-40Q (Warhawk) Single-Seat Monoplane Fighter Prototype Aircraft are showcased in the areas immediately below. Categories include basic specifications covering country-of-origin, operational status, manufacture(s) and total quantitative production. Other qualities showcased are related to structural values (namely dimensions), installed power and standard day performance figures, installed or proposed armament and mission equipment (if any), global users (from A-to-Z) and series model variants (if any).

Our Data Modules allow for quick visual reference when comparing a single entry against contemporary designs. Areas covered include general ratings, speed assessments, and relative ranges based on distances between major cities.

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Relative Maximum Speed Rating
Hi: 500mph
Lo: 250mph
    This entry's maximum listed speed (423mph).

    Graph average of 375 miles-per-hour.
City-to-City Ranges
Graph showcases the Curtiss XP-40Q's operational range (on internal fuel) when compared to distances between major cities.
Aviation Era
Pie graph section
Pie graph section
Pie graph section
Pie graph section
Pie graph section
Useful in showcasing the era cross-over of particular aircraft/aerospace designs.
Unit Production Comparison
Comm. Market HI*: 44,000 units
Military Market HI**: 36,183 units

  * Commercial Market High belongs to Cessna 172.

  ** Military Market High belongs to Ilyushin Il-2.

Altitude Visualization
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Origin: United States
Year: 1943
Type: Single-Seat Monoplane Fighter Prototype Aircraft
Manufacturer(s): Curtiss Aeroplane Company - USA
Production: 3
Status: Cancelled
Global Operators:
United States (cancelled)
Historical Commitments / Honors:

Military lapel ribbon for Operation Allied Force
Military lapel ribbon for the Arab-Israeli War
Military lapel ribbon for the Battle of Britain
Military lapel ribbon for the Battle of Midway
Military lapel ribbon for the Berlin Airlift
Military lapel ribbon for the Chaco War
Military lapel ribbon for the Cold War
Military lapel ribbon for the Cuban Missile Crisis
Military lapel ribbon for the Falklands War
Military lapel ribbon for the French-Indochina War
Military lapel ribbon for the Golden Age of Flight
Military lapel ribbon for the 1991 Gulf War
Military lapel ribbon for the Indo-Pak Wars
Military lapel ribbon for the Iran-Iraq War
Military lapel ribbon for the Korean War
Military lapel ribbon for the 1982 Lebanon War
Military lapel ribbon for the Malayan Emergency
Military lapel ribbon for the attack on Pearl Harbor
Military lapel ribbon for the Six Day War
Military lapel ribbon for the Soviet-Afghan War
Military lapel ribbon for the Spanish Civil War
Military lapel ribbon for the Suez Crisis
Military lapel ribbon for the Vietnam War
Military lapel ribbon for Warsaw Pact of the Cold War-era
Military lapel ribbon for the WASP (WW2)
Military lapel ribbon for the World War 1
Military lapel ribbon for the World War 2
Military lapel ribbon for the Yom Kippur
* Ribbons not necessarily indicative of actual historical campaign ribbons. Ribbons are clickable to their respective campaigns/operations.
Measurements and Weights icon
Structural - Crew, Dimensions, and Weights:
Unless otherwise noted the presented statistics below pertain to the Curtiss XP-40Q model. Common measurements, and their respective conversions, are shown when possible.




35.27 ft

10.75 m


35.20 ft

10.73 m


6,173 lb

2,800 kg


8,999 lb

4,082 kg

Engine icon
Installed Power - Standard Day Performance:
1 x Allison V-1710-121 liquid-cooled inline piston engine developing 1,425 horsepower and driving four-bladed propelled unit at the nose.


423 mph

680 kph

367 kts


994 mi

1,600 km

Nautical Miles
864 nm


39,009 ft

11,890 m

7.39 mi


2,000 ft/min

610 m/min

Supported Weapon Systems:

Graphical image of an aircraft medium machine gun
Graphical image of an aircraft heavy machine gun
Armament - Hardpoints (0):

4 x 0.50 caliber heavy machine guns in wings (two per wing).
Variants: Series Model Variants
• XP-40Q - Base Series Designation; three conversion models used in testing.
• XP-40Q-1 - Single example with Allison V-1710-121 engine driving four-bladed propeller unit.
• XP-40Q-2 - Two examples completed with cut-down fuselage, bubble canopy and clipped wing tips.