Republic P-44 (Rocket)

History

The road to the American WWII classic Republic P-47 Thunderbolt went through various iterations under the leadership of engineer Alexander Kartveli. In 1937, the United States Army Air Corps (USAAC) began operating the Seversky P-35 developed by Kartveli under the Seversky brand (Seversky reorganized as "Republic" in 1939). The P-35 was the first American-made single-seat, single-engine monoplane fighter jet with all-metal construction, a fully enclosed cockpit and fully retractable landing gear.

From this form, the P-43 "Lancer" was eventually developed and delivered to American, Chinese and Australian Air Services in 1941, with final production reaching 272.

Even before the P-43 came to fruition, there was a stopover on another Republic fighter - the P-44 "Rocket". The fighter was developed to meet new US Army requirements for an interceptor/tracker capable of a high speed range of 300 mph and a low speed of 420 mph when flying below 20,000 feet flight.

Republic beat out other submissions with their "AP-4J," which promised to meet the required specifications.

Design work was again directed by Kartveli, with propulsion from a single Pratt & Whitney R-2180-1 Twin Hornet 1,400 hp engine mounted on the nose. Of course, a monoplane wing configuration is also included, with rounded tips.

The fuselage is well contoured, and the radial piston engine is air-cooled and surrounded by a very narrow hood. In the stern, as usual, was placed a conventional rear wing with a rear wing. The "trail" landing gear is fully retractable. The cockpit has a raised fuselage spine and the frame is heavy enough to accommodate one operator amidships.

The armament was entirely based on machine guns: a combination of 2 x .50 caliber heavy machine guns and medium 4 x .30 caliber machine guns (a common arrangement for pre- and early-war American fighters).

The AP-4J's top speed was estimated to be around 385 mph, and the Army, taking into account the Republic's initiative, awarded the company a contract for 80 aircraft on September 13, 1939. Notably, there is a lack of any working, flyable prototypes to ensure a solid design.

By then, the war in Europe had only just begun (September 1), reports from the front became crucial to American observers, and it soon became apparent that modern European mounts outnumbered those offered by the Americans.

The AP-4J was further developed as the AP-4L with the installation of a Pratt & Whitney R-2800-7 series 2,000 hp air-cooled radial. Additional internal fuel storage will be provided to increase range. Cockpit armor is now an essential feature of fighter jets, as are self-sealing fuel tanks, so these also made their way into the revised P-44 design - now ordered by the Army on July 19, 1940 as the P-44-2. The original contract called for 225 fighter jets of the new standard, which was increased to 827 on September 9 of the same year.

Despite the extra weight, Republic engineers are optimistic that their new fighter will reach a top speed of 422 mph.

Once it hit the drawing board, however, the P-44 rocket was more or less replaced by events on the other side of the world. Fortunately, the Republic was also working on developing another "AP-10" fighter, which also caught the Army's attention in November 1939 - this plane became the XP before being known as the classic P-47 Thunderbolt- 47 prototype. With the XP-47 proving to be the more promising proposal, the P-44 project was completed on September 13, 1940, with no physical prototypes to show for yearsthat's the business of military aircraft design.

To keep the Republic production line open until P-47 manufacturing ramps up, authorities simply modified the P-44 contract to produce more P-43 Lancer fighter jets for the U.S. Army and its buying allies in China.

Specification

Basic

Production

Roles

Dimensions

Weight

Performance

Performance

Armor

Changes