Curtiss XP-60

History of the Curtis XP-60

On the eve of World War II (1939-1945), many attempts were made by many American companies to replace obsolete and retired fighter jets in service with the United States Army Air Corps (USAAC). Yet many such attempts by even the most prominent military airlines have been shelved. Curtis is best remembered for his early invasion of China - the P-40 Warhawk - which provided the Army with multiple possible fighter designs before the war and during the conflict.

However, none can match the success achieved by the P-40, and the XP-60 is the entry point into Curtis' long and storied history.

The new fighter design, known internally as the "Type 90", was presented to Army officials in January 1941 - 11 months before the United States entered World War II. The aircraft was built around the existing frame of the P-40 (P-40D), but with a more streamlined nose section (due to repositioned radiators) and an all-new laminar flow wing.

Power comes from a Rolls-Royce Merlin 28 inline engine - American built Packard V-1650-1 - a single-stage supercharged engine producing 1,300 horsepower that drives a Curtiss-Electric three-blade propeller unit. Has a seat, and A "trail" undercarriage was retained - the latter carried over from another Curtiss fighter project - the XP-46, of which only two were built.

An 8 x .50 caliber heavy machine gun was proposed as a weapon.

In less than a year, the new aircraft, called the "XP-60", had begun ground tests, with its first flight recorded on September 18, 1941. Test flights indicated that some changes were required, but they turned out to be minor to the overall structural form of the aircraft. In March 1943, the aircraft was handed over to Army authorities for formal testing, but there were several setbacks in the landing gear during this period.

The design performance combined with the Packard engine is also impressive.

While the XP-60 was still in development, a more powerful version was already being considered, and the "XP-60A" was eventually introduced. The aircraft carried a turbocharged Allison V-1710-75 rated at 1,425 horsepower, resulting in a partial rewrite of the XP-60's design form.

With the Army's interest in the new product, the service ordered 1,950 prototypes of the fighter in October 1941 as the production P-60A. However, despite the installation of alternative engines, the P-60A also exposed its own performance limitations.

With the Japanese attack on Pearl Harbor pushing the United States into the war, the commitment to P-40 production prevented production of the P-60A, and the initiative was abandoned in early 1942.

Even with this unexpected step, the XP-60A was allowed to continue its development, albeit purely experimentally. This includes aircraft with four-bladed propeller units and alternative wings. The aircraft is now referred to by Curtis as the "Type 95A."

After XP-60A, XP-60B became "Type 95B". This example features a Wright turbo, but is more or less the same product. The XP-60C ("Type 95C") had a slightly stronger airframe and was equipped with an experimental Chrysler XIV-2220 liquid-cooled engine. The addition of the Chrysler engine revealed some of the shortcomings of the now-overweight design.

This led to the switch to the air-cooled Pratt & Whitney R-2800 "Double Wasp" radial.

Work on the original XP-60 has progressed to now install a supercharged inline Merlin 61 series engine and rename the variant "XP-60D". However, the fuselage was lost in a flight accident during a diving demonstration on May 6, 1943. The XP-60A suffered its own misfortune in October 1942, when an engine fire killed it and forced some quick modifications. The maiden flight followed in November.

That same month, the airframe was removed from active testing and disassembled into parts.

The XP-60C was able to secure a new Army contract later that month for 500 aircraft of mass "P-60A-1". Switching to Pratt & Whitney engines offers promising performance upgrades, and the batch will include single and contra-rotating propeller shapes for evaluation and standard use. Both versions of the weapon are focused on 4 x .50 caliber heavy machine guns. A new variant of the XP-60E appeared, featuring a PWR-2800-10 with a four-bladed propeller and a GE turbocharger, although this model had a short lifespan. The XP-60C was unsuccessful in pre-flight competition with other types of the USAAF (United States Army Air Force), albeit with difficulties.

The government terminated interest in the P-60 as a production aircraft on June 3, 1943.

Development of the XP-60E continued until at least January 1944. The aircraft was then tested by the Army and compared with existing products actually used during the war.

Interestingly, at the request of the Army, which eventually took its final form, the aircraft received the development designation "YP-60E". The lines of the P-40 have all but disappeared from this model as it now looks more like the Republic P-47 "Thunderbolt" - low main plane, rounded wings, deep fuselage, four-bladed propellers and one more The Bubble Canopy YP-60E flew once for the US Air Force and was written off in December 1944.

Another proposed XP-60 form factor, known as the XP-60F, would be powered by an alternate version of the PWR-2800 series engine. This is not encouraged.

By this point, the service's stable of modern fighters has developed into an effective fighter-bomber -- the P-47, North American P-51 Mustang, and Lockheed P-38 Lightning have all performed well The place had a huge impact. 1944 was also a turning point for the Allies, leading to the end of the European War in May 1945.

In August of the same year, the Pacific War broke out.

The XP-60 program was a long and arduous one with little fruit in the end. It joins a slew of discontinued (or cancelled) Curtis products that could never match the popularity of his "Warhawk."

Specification

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Production

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Performance

Performance

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Changes