Bell XP-52 (Model 16)

History

As Europe was pushed down the path of total war in the late 1930s, the United States continued to strengthen its various military services. This led to a period of considerable testing and growth in the military aviation field, which favored classic designs from the WWII era (1939-1945).

A relatively newcomer to the field, Bell was one of the most advanced aerospace groups at the time, and while many of its designs never came to light, the company did play a role in keeping the U.S. ahead of potential adversaries.

In November 1939, the United States Air Force (USAAC) established requirements for a single-seat, single-engine fighter with performance specifications covering 425 mph at 15,000 feet per hour and a rate of climb of 2,857 feet per minute. Weapons will be centered on 4 automatic cannons (or machine guns) and ready for 6 20lb external bombs.

Rough field work will also be incorporated into the rugged design, and target a 1.5-hour mission endurance window - allowing the heavy fighter to reach far-flung areas or roam around when needed. All in all, the technical requirements were quite high at the time, requiring a lot of experimentation and engineering skills to achieve such a design.

Pratt & Whitneys XH-3130 inline liquid-cooled engine is at the forefront of what USAAC is considering to power its next-generation fighter jets, but the engine is still in development. It originated as a United States Navy (USN) program in the late 1930s and had 24 cylinders with an expected power output of over 2,500 horsepower.

Over time, this engine evolved into the larger XH-3730, which, although still in development, is thought to produce 3,000 horsepower.

The new aircraft design was submitted collectively under the "XC-622" tracking specification, which USAAC hoped would be operational as early as 1941.

Bell began work on their "Type 13", a design more or less focused on various engine mounts for their P-39C "Airacobra" propulsion fighter. The rear-mounted layout of the engines helps to simplify the airframe and clear the nose assembly of clutter, allowing for the installation of powerful armored batteries (such as cannons).

The propeller is still mounted on the nose, driven by the engine through a shaft under the cockpit floor. As this phase culminated, the company moved to the "Type 16," which included an entirely new airframe design.

With the Model 16 approach, a dual-arm design was chosen, but the rear-mounted position of the engine was retained. The engine initially selected was a Continental XI-1430-5 inline liquid-cooled engine tuned to produce 1,250 horsepower. This engine drives a pair of three-bladed propellers, which are placed in the rear of the fuselage in counter-rotating fashion. The fuselage basically properly carried the engines, fuel supply, cockpit, weapons and avionics. The wings were attached to the rear of the fuselage and received a slight rearward arrow with a rounded tip.

The tail boom originates from the center of the wing and passes through the trailing edge, and they are connected by a single horizontal plane between them at the very end of the aircraft. Circular vertical tailfins were added on either side of this horizontal plane.

Like the P-39 fighter before it, the Model 16 was originally intended to use three-wheeled landing gear in an era when "smearing" still ruled the runway.

The Army appreciated Bell's guidance and eventually assigned the project the working designation "XP-52". Two engine types were considered (Continental XI-1430 and Pratt & Whitney R-2800 "Double Wasp").

The Army began drafting contracts for two prototypes with the aforementioned engine modifications.

On the drawing board, the XP-52 has an overall length of over 34 feet, a wingspan of 35 feet, and a height of over 9 feet. It has an empty weight of 6,480 pounds and a loaded weight of 8,200 pounds, and the single-engine combined with the dual-arm design has a top speed of about 430 mph (at 20,000 feet). The rate of climb is within the required range and an upper operating limit of 40,000 is considered possible.

With a range of up to 960 miles, it gives the aircraft a good range.

The proposed armament for the XP-52 is a 2 x 20mm gun mounted on the nose assembly. Each of these guns received 100 short, controlled bursts of ammunition that could take down any bomber at the time. Each boom cable can also accommodate a "triple array" of .50 caliber heavy machine guns for a total of six heavy machine guns.

All in all, the weapons offered to the XP-52 were considerable by 1940 standards.

The XP-52 marked the US Army's first serious attempt to pursue a "propulsion fighter". However, before the end of 1940, the service decided not to continue the project. Bell went on to design the larger "Model 20" (designated "XP-59" by USAAC), described elsewhere on this site.

The project was also put on hold due to wartime commitments from Bell and the Army. Thruster fighters never made much progress in the war as tractors continued to dominate the skies.

The XP-52 was officially cancelled on November 25, 1941, before the Americans entered World War II.

Specification

Basic

Production

Roles

Dimensions

Weight

Performance

Performance

Armor

Changes