From 1923 to 1938, one aircraft defined U.S. military aviation during the so-called Golden Age of flight. The Curtiss Hawk dominated the era, with Navy, Marine Corps, and U.S. Army Air Corps units flying 410 of the aircraft in various versions.
The Hawk started as a private venture in 1922 to fill a void the military did not foresee. Glenn H. Curtiss sought to combine new technology—specifically, wire-braced, steel-tube fuselage construction and split-axle landing gear—with his powerful new 435-hp D-12 engine. The resulting Curtiss Model 33 prototype so impressed the Army, it purchased the plane and ordered two copies in April 1923. The type was designated PW-8 for Pursuit, Water-cooled, eighth model. These were followed by another 25. The Army changed its designation system about the same time, making them P-1s.
Never far from naval aviation, Curtiss sold versions to the Navy beginning in 1925 as the F6C-1, Curtiss Model 34C. Export versions were manufactured starting in 1926, with the production run of later variants extending into 1938. Curtiss built 717 Hawks: 278 for the Army, 132 for the Navy, and 307 for export and as company demonstrators. A further eight were constructed under license by Aviolana in the Netherlands.
Of the Navy Hawks, 32 were F6C-4 models, powered by air-cooled Pratt & Whitney R-1340 radial engines. The Navy opted for the different engine because it believed radials could be more easily maintained at sea.
The Hawk’s fabric-covered fuselage was built on a steel-tube frame with wood formers and stringers. Its engine cowling and cockpit surround were formed from sheet aluminum. Each wing was constructed on two spruce spars with built-up wood ribs and a plywood-covered leading edge. Ailerons and tail surfaces were welded steel tubing. All were fabric-covered.
Of the 132 Navy F6Cs, two are particularly noteworthy: Bureau Numbers A-7144 and -7147.
In the late 1920s, the Navy and Army air arms were in dire, if not perilous, straits. The naval aviation budget, for instance, had been slashed from $20 million in fiscal year (FY) 1920 to less than $7 million in FY 1921. Both arms sought to influence congressional appropriations through a publicity blitz with air-power demonstrations during air shows. From 1920 through 1925, the National Air Races featured the Pulitzer Trophy Race, a competition for the fastest time over a set number of laps of a closed course. The Army won four of the events and the Navy one. The military was prevented from participating in 1921, but civilian Bert Acosta won flying a Curtiss racer built for the Navy.
By 1925, Congress had become hostile toward the expenditure of funds on Army and Navy airplanes for racing purposes. This situation resulted in a new legal means to obtain funds for development programs without restrictions on flight tests. The original Navy program designation was 34D-RA-1, with “RA” indicating “Research Aircraft.” The designation was changed to 34D-AE-1 for “Advance Engineering,” as “RA” might have been interpreted as “Racing Aircraft.”
Because of limited funds, the Navy loaned A-7144 for the first experimental project. It was an attempt to inexpensively modify an airframe for better performance. The standard carrier-type F6C-3 was delivered to the Navy on 13 November 1926. It was later converted to a seaplane, and then to a landplane.
In February 1929, the aircraft was sent to the Naval Aircraft Factory for reconditioning and preparation for modifications to the AE-1 configuration by Curtiss. It was released to the Navy for further tests that July. The changes included a streamlined engine cowling, side-mounted radiators, faired rear fuselage, and cockpit fairings. It was entered in the 1929 Cleveland Air Races for the 50-mile Thompson Cup Race in September.
Redesignated as F6C-6, it was flown with streamlined wheel pants from a surplus Navy Great Lakes trainer. Lieutenant Commander Joseph J. Clark—later Admiral “Jocko” Clark of World War II and Korean War fame—finished fourth in a field of eight with a speed of 153.38 mph. The winner, Doug Davis, in a civilian Travel Air-R “Mystery Ship,” crossed the line with an average speed of 194.40 mph. After the race, the F6C-6 was returned to Curtiss for the follow-on AE-2 project.
The AE-2 was another limited-budget experiment, this time for developing a high-speed parasol-wing aircraft based on the Hawk and using existing tools and jig fixtures. A-7144 had its lower wing panels removed, and a lightweight wing brace structure was installed. Wooden fairings were fitted to the lower wing-root openings, and a new nose was designed for propeller tests. As a parasol, the hybrid Hawk flew with no problems in takeoff, flight, and landing. Its top speed was 191 mph, and its ceiling was 18,000 feet; a standard F6C-3 was rated at 154 mph and 22,900 feet. After completing the AE-2 program, A-7144 was restored to its original F6C-3 landplane configuration and returned to the Navy. The streamlined rear fuselage, however, was not changed. The plane was stricken from the Navy List on 28 December 1931.
F6C-3 A-7147 had an amazing career by any standards. It was delivered to the Marine Corps at Quantico, Virginia, on 29 November 1926. The next June, it suffered its first of five significant crashes. By the following spring, however, the repaired fighter was entered in the 19 May 1928 Curtiss Marine Flying Trophy Race for floatplanes. Flown by Major Charles A. Lutz, it won the 100-mile race with an average speed of 157.60 mph.
Just three days later, while flying back to base at Quantico, the engine quit a half-mile from the field. The plane struck a horse hurdle and flipped on its back. Lutz escaped unharmed. On 23 June, he was not so fortunate. He perished in the crash of a Marine Corps Atlantic-Fokker TA-2 tri- motor bound for Nicaragua.
On 23 October, A-7147 crashed a third time but was only slightly damaged. Its fourth accident occurred on 17 November 1929, and it was deemed beyond repair. The Marines, however, worked a miracle, and once again had the ship airworthy. On 31 May 1930, A-7147 won the Curtiss Marine Flying Trophy for an unheard of second time, this time with Captain Arthur H. Page at the controls. His speed was a series record of 164.08 mph. This version of A-7147 was modified from Lutz’s incarnation. It had a radiator scoop extension and faired belly structure aft of the outlet, a new windshield, streamlined headrest fairing, and a tightly enclosed cockpit area. All rivets, cowl butt lines, and zipper inspection panels were taped, and fairings on wings and wires were handmade of plastic, wood, and sheet aluminum. Its entire surface was highly waxed.
Less than two weeks after the victory, Lieutenant Walter S. Diehl, director of aerodynamics at the Bureau of Aeronautics, sent a note to Commander Walter W. Webster, chief of the bureau’s Design Division, at the behest of the bureau’s Lieutenant Commander Arthur C. Miles. It concerned the conversion of an F6C-3 for the National Air Races. On 11 June, Page gave Diehl notes from Curtiss showing incremental speed increases with various modifications. Diehl related that, based on his estimates, the designed goal of 250 mph might be attainable with the Hawk’s standard 600-bhp engine, but an increase to 750 bhp would “take care of the ‘assembly’ defects that cannot be avoided except by a new design.”
The Curtiss Model 34D-AE-3 was to be the prototype for a new line of parasol-wing fighter and pursuit types. A-7147 was selected for the project, and the new aircraft was designated XF6C-6 in July 1930.
A-7147 was stripped and rebuilt on a limited budget. Funds were siphoned from other projects to pay labor costs; engineers were volunteers. The Army loaned a powerful 750-hp Curtiss V-1570-1 Conqueror engine and wing panel WU26-295. The wing, with flush skin radiators, had been built for the 1927 National Air Races but was not completed in time.
The AE-3 project aircraft was finished in 65 days for $21,000; it was flight-tested by Paul Boyd, John Barr, and Page. The only problem was control flutter at speeds above 221 mph.
Except for the tail, virtually nothing about the aircraft said “Hawk.” It was sleek and looked racy and fast. Its landing gear was completely faired with streamlined wheel pants. Its gloss navy blue paint scheme only heightened the effect.
On 1 September 1930, Page and A-7147 were the clear favorites to win the first Thompson Trophy Race at Curtiss-Reynolds Airport north of Chicago, with the plane having nearly twice the power of the other entrants. Page led off at the start with a ten-second interval between aircraft. Three laps into the 20-lap event, Page was already far ahead. On the 17th circuit of the five-mile course, he had lapped the field. But starting the next lap, the plane veered to the center of the circuit and crashed. Although pulled from the aircraft alive, Page succumbed to his numerous injuries later that night.
Initially it was thought—and many today still believe—that carbon monoxide poisoning led to Page’s loss of control and crash. The Navy’s Aeronautical Engine Laboratory tore down the engine and did a minute inspection. It determined that the magneto drive shaft bushing and housing failed, which most likely retarded the magneto timing enough to cause a loss of power and engine failure.
Nothing remains of A-7147 except for the borrowed engine, which is in the collection of the National Air and Space Museum.
