The Boeing F4B/P-12 series served as the primary fighter of the U.S. Navy and U.S. Army Air Corps in the early 1930s, and it remained in service in numerous roles until the early 1940s. It was the last wooden-winged, biplane fighter produced by Boeing and used by the U.S. military. The large quantity of F4B/P-12s built and purchased helped to establish Boeing as an important aircraft manufacturer and to sustain the firm through the economic hardships of the Great Depression.
Two prototypes designated XF4B-1 were first flown on June 25, 1928, and delivered to the Navy for evaluation. Convinced of the merits of the design after extensive trials, the Navy purchased twenty-seven production aircraft. The first were delivered in the summer of 1929 to the Red Rippers of VB-1B on the U.S.S. Lexington. The new fighter was capable of reaching speeds of more than 175 mph, and could carry five 11-kg (24-lb) bombs under each wing, with either one 225-kg (500-lb) bomb or one 155-liter (41-gallon) fuel tank beneath the fuselage. Armament on the F4B-1 consisted of two .30-caliber machine guns synchronized to fire through the propeller arc.
Following the success of the first model, the Navy contracted for forty-six improved versions in June 1930, with deliveries beginning in January of the next year. The F4B-2 differed in having a redesigned ring cowling, improved split-axle landing gear, and Frise ailerons. Maximum speed was increased to 298 kph (186 mph), and the airplane could carry four 56.2-kg (116-lb) bombs.
Encouraged by the Navy's results with the XF4B-1, the Army placed an order for ten similar aircraft with the carrier hook deleted. The Army version was designated the P-12. The first P-12 was flown to Central America on a goodwill mission by then Captain Ira C. Eaker in February 1929. The next model, the P-12B, was an upgraded version with Frise ailerons and a shorter landing gear. Ninety were produced. In June 1930, the Army Air Corps contracted for 131 P-12C models, which incorporated the P-12B airframe with a ring cowl and a cross-axle landing gear. Although the last thirty-five of the order were identified D models, they were identical to the P-12C. The naval equivalent was the F4B-2.
While production of the F4B-2 was in progress, Boeing began development of a new version. Instead of the bolted, alloy-tube fuselage of the earlier design, the F4B-3 had an all-metal semi-monocoque fuselage. The two-spar, fabric-covered wings with corrugated metal control surfaces were retained. The engine was the Pratt & Whitney R-1340-10, which was fitted with a drag ring. The Navy contracted for seventy-five F4B-3s; the first airplane was delivered on Christmas Eve in 1931. Built for the Army as the P-12E, the new version represented Boeing's largest Army contract since the MB-3A in 1921. Of the 135 ordered, 110 were delivered as P-12Es. The remaining twenty-five were delivered as P-12Fs, employing Pratt & Whitney SR-1340G engines for increased high altitude performance.
The fourth and final version of the F4B series was the F4B-4. Essentially an F4B-3 with a broader chord fin and a larger headrest for an inflatable life raft, the F4B-4 was first ordered in April 1931, and the last of ninety-two aircraft were delivered on February 28, 1933. Twenty-one of these airplanes were assigned to the U.S. Marine Corps. The F4B-4 maintained the good flight characteristics of the earlier versions despite greater weight and increased power. Only when overloaded and at maximum speed did the F4B-4 exhibit any instability.
Total production of the F4B/P-12 reached 586; almost 350 were ordered by the Army. Two were sent to Thailand where one remains today on display in the Royal Thai Air Force Museum, and twenty-five were built for Brazil. Of these, only one ever saw combat. Model 281, from which the F4B-3 and P-12E were developed, was sold to China where it was shot down by the Japanese after downing two of its three attackers.
The airplane in the NASM collection is one of the twenty-one F4B-4s built for the Marine Corps. The only difference from the standard Navy configuration is the absence of a tail hook. Number 9241 was shipped from the Boeing factory in Seattle on December 20, 1932, arriving nine days later at the North Island Air Station in San Diego, California. This F4B-4 was assigned as the number two aircraft in Marine Fighting Squadron 10, and served there until July 1933. All the F4B-4s of the squadron were transferred to VF-9M at Quantico, Virginia, where 9241 flew until the F4Bs were replaced by more modern Grumman F3F-2s. The airplane then served as a trainer until purchased by the Bureau of Air Commerce and was stricken from the Navy inventory on July 31, 1939. Shortly thereafter it was purchased by Bellanca Aircraft Corporation and later re-sold to private owners. Number 9241 was donated to the Smithsonian Institution in 1959 by its last owner, Ray Hylan, of Rochester, New York. It is now in its former colors as airplane number 21 of Marine Fighting Squadron VF-9M.
