During the 1920s and 1930s scores of aircraft firms around the world developed flying boats for both military and commercial roles. One that was successful, but not produced in large numbers—nor generally remembered—was the Hall PH flying boat.
Engineer Charles Ward Hall founded the Hall Aluminum Aircraft Company in 1927 in Buffalo, New York, to build all-metal aircraft for the U.S. Navy. He was the son of Charles Martin Hall, inventor of the definitive aluminum-refining process and founder of what became the Aluminum Company of America (Alcoa). The younger Hall began research into aluminum-hull flying boats with the Aeromarine firm in 1916. A decade later he designed the PH flying boat. It was derived from the long series of flying-boat designs produced by the Naval Aircraft Factory in Philadelphia, which in turn had been based on the British F.5 Felixstowe flying boat of World War I.
Although Hall produced few PH flying boats—a total of 24 for the U.S. Navy and Coast Guard—the aircraft was well liked and gave long service.
The PH was a twin-engine biplane, constructed largely of aluminum, with fabric-covered wings. The “boat” fuselage provided an enclosed cockpit for the two pilots with open cockpits for the nose gunner and a second gunner amidships. The two radial engines were mounted on struts between the wings. Fixed stabilizing floats were fitted under the lower wing. The aircraft had a single, tall tail fin. For beaching operations, a wheeled undercarriage could be rapidly attached and removed while the flying boat was in shallow water.
The prototype XPH-1, similar to the Navy-built PN-11, was ordered in late 1927 and first flew in December 1929. The pilots sat side by side in an open cockpit—a feature that was changed in the production aircraft, which had an enclosed cockpit. The prototype was successful, although, as aviation historian Robert F. Dorr wrote, “Aircraft of this kind were noisy and shaky but reliable.”1
Subsequently, the Navy ordered nine PH-1 production aircraft with more powerful engines (and the enclosed pilots’ cockpit). These went to Patrol Squadron (VP) 8 at San Diego, which flew the Hall flying boats from 1932 to 1937. Some of these planes remained in Navy inventory for several more years in the training role.
By 1934 Hall had moved his expanding operation to Bristol, Pennsylvania, taking over facilities of the Keystone Aircraft Corporation. That firm had ceased production there in 1932 when it became a division of Curtiss-Wright.
Significantly, the main operator of the Hall flying boat was the Coast Guard.2 The aircraft’s quick takeoff and slow landing speed facilitated operations in rough water; these characteristics coupled with its long range made the Hall PH series ideal for Coast Guard operation. Beginning in 1936 the service took delivery of seven PH-2 variants, the main difference over their predecessors being more powerful engines and the fitting of rescue gear.
The largest aircraft operated by the Coast Guard prior to World War II, the PH-2 could accommodate up to 20 passengers/survivors plus a normal crew of a pilot, navigator, radio operator, and flight mechanic. Stretchers could be loaded through hatches and moved on a track that penetrated some of the five bulkheads that divided the hull into six watertight compartments. When empty and at its most efficient altitude—2,800 feet—the plane had an endurance of 20 hours at a speed of 150 miles per hour. A PH-2 was lost during a rescue mission in 1939.
These flying boats were followed by an order to Hall for seven PH-3 variants for the Coast Guard. Generally similar to the PH-2, these were delivered beginning in 1939. One crashed in 1941, but the others—like the PH-2s—served in a maritime-patrol/antisubmarine capacity during World War II, primarily flying from Elizabeth City, North Carolina, and St. Petersburg, Florida. In this combat role the Coast Guard flying boats were armed with up to four .30-caliber Lewis machine guns and carried four 200- or 250-pound depth bombs.
While the last of the Navy’s PH-1 flying boats had been retired from squadron service with VP-8 in May 1937, the PH-2 and PH-3 aircraft served the Coast Guard until 1944.
The Hall flying boats were the last biplane patrol aircraft in U.S. service and were among the last biplanes to fly with U.S. military markings.
The Hall Aluminum Aircraft Company produced three other prototypes for the Navy—the XFH-1 shipboard fighter (1929); the XP2H biplane, four-engine flying boat (1931); and the XPTBH large torpedo-bomber seaplane (1936). But only the PH series—although produced in relatively small numbers—became a memorable historic aircraft.
(The author appreciates the special assistance of James Caiella in producing this column.)
2. The most detailed published account of Coast Guard PH aircraft is Arthur Pearcy, U.S. Coast Guard Aircraft Since 1916 (Annapolis, MD: Naval Institute Press, 1991), 220–24.
Type: Maritime patrol and search-and-rescue flying boat
Crew: 4 to 6 plus 20 passengers
Gross weight: 16,152 pounds
Length: 51 feet
Wingspan: 72 feet, 10 inches
Wing area: 1,170 square feet
Height: 19 feet, 10 inches
Engines: 2 Wright R-1820F-51; 750 horsepower each
Max. speed: 159 mph at 3,200 feet
Range: approx. 2,000 miles
Ceiling: 21,350 feet
Armament: 4 .30-cal. Lewis machine guns; 4 depth bombs