Republic XP-72 Ultrabolt

Republic History XP-72 Ultrabolt

The Republic XP-72 Wasp Major-powered "Super Thunderbolt" (or "Ultrabolt") was developed during the second half of WWII (1939-1945) as the ultimate incarnation of the war-winning P-47 Thunderbolt/fighter-bomber ( also made by the Republic). The XP-72's airframe is roughly the same as the large experimental Pratt & Whitney R-4360 "Major Wasp" production engine rated at 3,450 hp.

Despite the promise of high-altitude fighters, there was ultimately not much demand for such aircraft as the nature of warfare changed. No more than two prototypes.

For convenience, the XP-72 uses the proven fuselage and wings of the previous P-47. Some changes were made to the airframe to accommodate the larger Pratt & Whitney, including a revised lower fairing to allow for proper engine intake.

A large diameter four-bladed propeller unit is attached to the power unit. Compared to the original P-47 product, the aircraft was actually considered a "Super Thunderbolt".

The second prototype featured an Aero Products counter-rotating propeller arrangement (three-blade units mated into a single engine, six blades in total), with an estimated top speed of 550 mph. The primary armament was a wing-mounted row of 6 x 12.7mm (0.50 caliber) machine guns (reduced from the 8 x 12.7mm machine guns in the original P-47 Thunderbol). An alternative weapon built into the treaty is to allow the use of 4 x 37mm autocannons instead of all machine guns.

As a secondary weapon, the aircraft will carry high-explosive rockets, 2 x 1,000 lb bombs, or 2 fuel tanks at hardpoints under each wing, as appropriate.

Despite the improved performance and relatively simple development process, the conditions later in the war were that there was little demand for an all-new high-altitude fighter/interceptor, as existing types were sufficient to fill the role. The simple fact is that the XP-72 is no longer a necessity on the wider spectrum of warfareespecially now that propeller-driven aircraft has reached its technological zenith and turbojet technology is beginning to dominate.

As a result, two XP-72 prototypes were withdrawn for further development and scrapped until the end of the war, while the production contract for 100 examples of the type was cancelled. The XP-72 "Super Thunderbolt" would fail as another WWII "what if" program that ended the war without any tangible results - let's imagine the impact if they were really such a powerful aircraft Put into operation immediately.

Specification

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Performance

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