History
The Bell XFL-1 Airabonita was an experimental carrier-based interceptor developed by Bell for the U.S. Navy, aiming to replace outdated biplane fighters still in service. Designed in response to a Navy specification issued on January 1, 1938, the XFL-1 was envisioned as a lightweight, high-performance fighter.
Bell submitted its design proposal alongside Brewster, Curtiss, Grumman, and Vought-Sikorsky on April 11, 1938. After review, the Navy awarded prototype contracts to Bell, Grumman, and Vought-Sikorsky for testing and evaluation. Bell received a contract on November 8, 1938, to proceed with the carrier-based XFL-1 Airabonita, also developed in parallel with the land-based XP-39 Airacobra for the Army. The XFL-1 was powered by a 1,150-hp Allison V-1710-6 inline engine driving a Curtiss Electric three-blade propeller, though it lacked a high-altitude supercharger.
One key difference between the XFL-1 and the XP-39 was the undercarriage configuration: the XFL-1 used a conventional tailwheel landing gear instead of the XP-39’s tricycle gear, making it better suited for carrier operations. The XFL-1 also featured a larger wingspan, shorter fuselage, and a smaller rudder. The pilot’s seat was raised, which required a modified canopy design for visibility, and a small window was added below the nose to aid in carrier landings. The airframe was strengthened to withstand the stresses of carrier operations, and an arresting hook was installed. Additionally, the air inlets originally located in the wing roots were later replaced with under-fuselage scoops due to repositioned main landing gear struts to correct the shifted center of gravity.
The XFL-1’s armament included two .30-cal machine guns and one .50-cal machine gun. The mockup was inspected on December 20, 1938, but development was slowed by issues with the center of gravity, pushing back its expected first flight to the fall of 1939.
By April 1940, Bell completed the XFL-1 prototype, which underwent its maiden flight on May 13. However, this flight was accidental, as the aircraft was performing a high-speed taxi test when a gust lifted it off the runway. The test pilot managed a safe landing despite the unexpected takeoff and the flotation bags in the wings inflating mid-flight. The second flight attempt on May 20 ended abruptly when the engine failed shortly after takeoff, forcing an emergency landing in a nearby ditch.
Flight testing exposed significant challenges, including yaw oscillations, poor handling, and inadequate cooling. During a flight on June 29, the XFL-1 entered a spin due to yaw issues, but the pilot recovered when a Plexiglas canopy panel broke off, unexpectedly altering airflow over the rudder. These and other issues led to multiple modifications.
In July 1940, the Navy began official evaluation, but the XFL-1 struggled with carrier suitability, mainly due to its problematic landing gear. Additionally, the Allison engine, with its single-speed supercharger, provided inferior altitude performance compared to Navy fighters like the Grumman F4F Wildcat. The Navy sent the prototype back to Bell in December 1940 for further modifications, and it was returned to Naval Air Station Anacostia in February 1941 for continued testing.
Although the modifications improved stability and control, they added considerable weight, increasing the XFL-1’s empty weight by 8% and reducing its top speed from a promised 339 mph to 333 mph. Worse, the minimum airspeed rose to 78.6 mph, exceeding the Navy’s 70-mph limit for safe carrier landings, disqualifying it from carrier use.
Ultimately, the Navy canceled the XFL-1 program. The Chance Vought XF4U-1 Corsair, which achieved 400 mph in testing, proved a more promising option for carrier operations. The XFL-1’s limited armament and performance shortcomings made it uncompetitive, and in 1942, the prototype was used for destructive armament testing. The remains were ultimately last seen at Naval Air Station Patuxent River, marking the end of Bell’s attempt to produce a carrier-based interceptor for the Navy.
