Grumman F4F Wildcat


The 27-year old pilot would be decorated with the Navy Cross for his valor in defending (though in vain) his mother ship. Lt Cdr Elbert McCuskey ended the war as a recipient of 15 decorations. A winner of 14 aerial combats, he retired from the US Navy in 1965.

 Wildcat BuNo0383 with rounded wingtips – an in-flight depiction. Colors: Glossy Orange-Yellow (top of the wings) and Aluminum (other surfaces).[Via Andre R. Zbiegniewski]

 

Origins, Design and Development
The mid-thirties was the zenith of the biplane era and it was a biplane type that the Grumman Aircraft Corporation entered into the competition for a naval fighter announced in August 1935 by the Bureau of Aeronautics. The corporation had much experience as it had previously delivered several types of fighters to the US Navy.
G-16’s design was approved by the Bureau of Aeronautics and on 2 March 1936 Grumman signed a contract for the construction of a prototype designated XF4F-1. The biplane’s imminent obsolescence was confirmed by the winning design preferred by the US Navy, a Brewster monoplane (B-39). Company owner, Leroy R. Grumman, ordered the design to be re-worked into a mid-wing monoplane configuration as soon as he heard the news. The Bureau of Aeronautics agreed to annul the contract for the XF4F-1 and on 28 July signed contract no. 46973 for monoplane XF4F-2, which received a serial number BuNo0383. In the production plant it was designated G-18.
William T. Schwendler’s construction team decided to use a 14-cylinder Pratt & Whitney R‑1830-66 Twin Wasp radial engine developing 1050 hp take-off power, with a single-stage, single-speed supercharger. In order to speed up the work on the prototype construction, as many details as possible were taken from XF4F-1’s design; from the similar thick belly fuselage outline to the retractable undercarriage patented by Grumman, retracting into the lower forward fuselage. The barrel-shaped fighter was of similar dimensions to the Brewster design and featured a mid-wing. The cockpit was relocated forwards and two small windows were inserted on each side of the lower part of the fuselage to improve visibility. Armament included two or four half-inch caliber Colt-Browning machine guns. Two of them could be mounted over the engine and two in the wings.
The prototype was test-flown by Robert L. Hall from an airfield adjacent to the production plant in Bethpage on 2 September 1937. In the event the plane was somewhat lacking in agility, had an inefficient engine and unsatisfactory longitudinal stability. Nevertheless the construction was considered a success and despite engine problems the XF4F-2 was delivered on 23 December to NAS Anacostia where it underwent fly-off trials against the Brewster XF2A-1 and Seversky XNF-1. Even though Grumman’s fighter proved to be the fastest of the three, its power-plant was the undoing of the prototype. On 11 April 1938 during tests in NAF Philadelphia the engine suddenly seized and the resulting forced landing saw the machine cartwheel onto its back. The pilot, Lt Gurney from the US Navy, was not badly hurt. The incident set the members of the qualifying committee against the XF4F-2 prototype and the US Navy signed up with the Brewster.
However Roy Grumman had no intention of letting the matter rest there. After frequent visits to the Bureau of Aeronautics he was given a “last chance” list of necessary improvements. This meant a thorough re-design of the prototype. The Bureau officials liked the new design and in October Grumman signed a production contract for the modified prototype, designated XF4F-3.

Prototype Wildcat with disassembled engine cover. [Via Andre R. Zbiegniewski]


The modifications were major. The wingspan was increased from 10,36 to 11,58 m and the wingtips, previously rounded, were given a rectangular outline. A Curtiss Electric adjustable-pitch airscrew was used in place of a two-pitch Hamilton Standard, while the engine was a prototype Pratt & Whitney XR-1830-76 Twin Wasp capable of 1200 hp and equipped with a double-speed, double-stage supercharger. The engine cowl had to be lengthened. The armament was also modified with provision for the mounting of two 0.5in caliber guns over the engine and in the wings.
The XF4F-3 prototype was test-flown by Robert L. Hall on February 12th, 1939. A series of test flights showed that the prototype engine had a tendency to overheat. Nonetheless on 7 March the plane was flown to NAS Anacostia for trials.
Two months of testing revealed problems with directional stability and maneuverability. The XF4F-3 was returned to the manufacturer for the necessary modifications. These included raising the location point of the tail plane where it was mounted to the lower part of the fin and increasing its surface. The wings’ dihedral was slightly raised and the ailerons’ surface was decreased. Moving the antenna mast to the top of the fuselage was a less significant change.