World War Photos

Grumman XF4F-5

The Grumman XF4F-5 Wildcat was a specialized experimental variant of the Wildcat series, primarily designed to test the feasibility of using the Wright R-1820 Cyclone engine instead of the Pratt & Whitney Twin Wasp engine that was standard on other Wildcat models. This variant was developed as part of Grumman’s efforts to explore different engine configurations and their potential performance benefits.

Grumman XF4F-5 Wildcat Overview:

1. Development and Background:

   • The XF4F-5 was an experimental version of the Wildcat that differed primarily in its powerplant. Grumman developed two prototypes to test the effectiveness of the Wright R-1820 Cyclone engine, a 9-cylinder, single-row radial engine, compared to the 14-cylinder, twin-row Pratt & Whitney engines used in other Wildcats.
   • The two prototypes, with Bureau Numbers 1846 and 1847, were the third and fourth aircraft built in the F4F-3 series, repurposed for this experimental role.

2. First Flight:

   • The XF4F-5 made its first flight in June 1940.

3. Production Details:

   • Total Number Built: 2 units
   • USN Bureau Numbers: 1846 and 1847

4. Physical Characteristics:

   • Wingspan: 38 feet
   • Wing Area: 260 square feet
   • Length: 28 feet 10 inches
   • Height: 11 feet 10 inches

5. Powerplant and Propulsion:

   • Prototype 1846: Initially powered by a Wright R-1820-40 Cyclone engine producing 1,200 horsepower at takeoff, this aircraft was later fitted with a Wright R-1820-54 engine with a turbo-supercharger, enabling it to achieve a maximum speed of 340 miles per hour at 26,400 feet.
   • Prototype 1847: Also initially equipped with the Wright R-1820-40, it was later modified with a Wright XR-1820-48 engine featuring a two-stage supercharger. This configuration allowed the aircraft to reach a top speed of 316 miles per hour at 19,300 feet.
   • Both aircraft used a Hamilton Standard 3-blade constant-speed propeller.

6. Armament:

   • The XF4F-5 prototypes were not fitted with any armament, as they were strictly used for engine performance testing and evaluation.

7. Weight and Performance:

   • Empty Weight: 4,887 pounds
   • Gross Weight: 6,063 pounds
   • Maximum Speed:
     • Prototype 1846: 306 miles per hour at 15,000 feet initially, later achieving 340 miles per hour at 26,400 feet after engine modification.
     • Prototype 1847: 316 miles per hour at 19,300 feet after engine modification.
   • Normal Range: Unknown
   • Initial Climb Rate: 2,350 feet per minute
   • Service Ceiling: 35,500 feet

8. Operational History:

   • The XF4F-5 prototypes were used primarily for testing and evaluating the Wright Cyclone engines to determine their suitability for the Wildcat. The tests aimed to explore whether the simpler, single-row radial engine could provide comparable performance to the more complex twin-row Pratt & Whitney engines.
   • Despite the successful test results, which demonstrated impressive performance at higher altitudes for prototype 1846, the U.S. Navy ultimately chose to continue with the Pratt & Whitney engines for the Wildcat series. This decision was likely due to the already established production and reliability of the Pratt & Whitney engines.