By PETER M. BOWERS.
The first Curtiss Hawks for the U.S. Navy were nine F6C-1s, direct equivalents of the Army P-1s, and were delivered late in 1925. The designation meant a fighter model (F), the sixth ordered from Curtiss. The –1 identified the initial configuration. These were used mostly by the U.S. Marines from shore bases as they were not equipped for carrier operations. The last four, however, were completed as F6C-2 with arrester hooks and high-impact landing gear for operation from the Navy’s single carrier of the time. These led to an order for 35 outwardly identical F6C-3s. All models through the –3 could be fitted with twin floats and, for a while in 1927-28, one squadron, the famous “Red Rippers,” used F6C-3 seaplanes. This was the Navy’s last use of floatplane fighters.
In the late 1920s, the Navy began to phase liquid-cooled engines out of fleet service. The first F6C-1 was tested with a 410-hp air-cooled Pratt and Whitney “Wasp” radial engine, and as the XF6C-5 when refitted with a 525-hp Pratt and Whitney “Hornet” engine, but there was no further production. The production –4s had improved landing gear for carrier work.
The liquid-cooled models had a power and speed advantage, however, so were used for racing in the days when the services competed with civilians in the National Air Races. One F6C-3 was cleaned up extensively for the 1928 and 1929 races. In 1929 it was redesignated F6C-6 before being reconverted to a stock F6C-3.
The most radical modification to any Hawk was to the F6C-3 that became the XF6C-6 for the 1930 National Air Races. This made a major reduction in drag by eliminating the lower wing and moving the upper wing aft to maintain the balance. The standard 435-hp Curtiss D-12 engine was replaced by a specially hopped-up Curtiss “Conqueror” that delivered 770 hp instead of the normal 600. The drag of the conventional radiator was eliminated by reverting to the old wing surface radiators of the 1922-25 Curtiss racers and the PW-8s. One major change that was to affect future designs was a low-drag single-leg landing gear. The development of this on a racing plane can be cited as one of the beneficial aircraft improvements brought about by the races.
The XF6C-6 had a calculated top speed of 250 mph, but never got to prove it since it wasn’t thoroughly tested before the race. It was leading the field in the 1930 Thompson Trophy Race with a lap speed of 219 mph when the pilot, Marine Corps Capt. Arthur Page, was overcome by carbon monoxide fumes and crashed. This misfortune ended service participation in civil racing and also marked the end of the Navy’s own Curtiss Marine Trophy Race for service seaplanes.
The Navy carried on with the Hawk as a biplane fighter, but there were so many changes in the next version that it got a new model number, F11C. There were two prototypes, XF11C-1 and –2. The production order was for 32 F11C-2 fighter-bombers with 700 hp Wright “Cyclone” radial engines and the single-leg gear of the XF6C-6 and the Army XP 22. After a year in service, these were redesignated BFC-2 for Bomber-Fighter in 1934.
The last F11C-2 was held at the factory for completion as the XF11C-3, which featured a retractable landing gear similar to that recently introduced by Grumman. The 27 production versions were BF2C-1. This model was very troublesome and was withdrawn from service in 1937. A few obsolete Army P-6Es carried on into 1940.
The export models pretty well matched the U.S. service models and remained in production into 1936. The last biplane Hawk built was the export Hawk IV, essentially a cleaned-up BF2C-1 with the addition of a closed canopy.
Three original Hawks are known to exist today: a P-6E in the Air Force Museum, a civil Hawk 1A (Al Williams’ original “Gulfhawk”) in the USMC Aviation Museum at Quantico, Va., and an export Hawk III (BF2C-1) in the Royal Thai Air Museum in Bangkok.
PROTOTYPE: The single-leg landing gear of the XF6C-6 was perpetuated in later Hawks, including the Navy F11C-2 of 1933, which was soon redesignated BFC-2. Export equivalents were marketed as Hawk II.
THE MORE THINGS CHANGE: Retractable landing gear on the last F11C-2 produced the XF11C-3. Production versions were BF2C-1 and export versions were Hawk III. In spite of all the changes to the fuselage, the wings and tail of the Hawk remained essentially as built in 1924.
UNREALIZED POTENTIAL: The most-modified Hawk was the XF6C-6, an F6C-3 converted to a monoplane and fitted with a larger engine for the 1930 National Air Races. Its potential 250 mph speed was never proven. It crashed during the 1930 Thompson Trophy Race.
FLOATING FIGHTER: The Navy used F6C-3 seaplanes as floating fighters in 1928 and 1929. This was the Navy’s last use of floatplane fighters.
END OF THE LINE: Final version of the Hawk, and the only example built, was the Hawk IV for export. Notable difference from the others was the enclosed cockpit.
This is a classic Of Wings & Things from the 1980s. GAN will continue to run the late Mr. Bowers’ column for the enjoyment of his readers.