Design & Development

The F3D was not intended to be a typical sleek and nimble dogfighter, but it was a night fighter packing a powerful radar system and second crew member. It originated in 1945 with a U.S. Navy requirement for a jet-powered radar-equipped carrier-based night fighter. The Douglas team led by Ed Heinemann designed around the bulky air intercept radar systems of the time, with side-by-side seating for the pilot and radar operator. The result was an airplane with a wide, deep, and roomy fuselage. Instead of ejection seats, an escape tunnel was used, similar to the A-3 Skywarrior.

Power was provided by two Westinghouse J34 turbojets mounted in the roots of then-standard straight wings of the early jet era. As a night fighter that was not expected to be as agile as smaller daylight fighters; the expectation was to be a stable platform for its radar system and the four 20 mm cannon mounted in the lower fuselage. The U.S. Navy awarded Douglas a contract for three XF3D-1 prototype aircraft on 3 April 1946. (The losing design from Grumman evolved into the F9F Panther.)

The radar system in the F3D-1 was the Westinghouse AN/APQ-35. The AN/APQ-35 was a combination of three different radars, each performing separate functions: an AN/APS-21 search radar, an AN/APG-26 fire control radar, both located in the nose, and an AN/APS-28 tail warning radar. The complexity of this radar system, which was produced before the advent of semi-conductor electronics, required intensive maintenance to keep it operating fully.

F3D-2 Skyknight
Maintenance on the Westinghouse APQ-35 radar of a Douglas F3D-2 Skyknight night fighter of Marine night fighter squadron VMF(N)-513 Flying Nightmares parked at airfield Kunsan in the Summer of 1953. Note APQ-35 standing on the right and the radar housing beyond.
[Source: USN]

First flight of the XF3D-1 occurred on 23 March 1948. A production contract for 28 F3D-1 production aircraft soon followed in June 1948. The F3D-1 was followed by the F3D-2, which was first ordered in August 1949. The F3D-2 was intended to have Westinghouse J46 engines in enlarged nacelles to replace the J34—WE-32 engines of the F3D-1. Development problems with the J46 lead to F3D-2 aircraft being fitted with J34-WE-36 engines instead. The F3D-2 also incorporated an improved Westinghouse AN/APQ-36 radar system. A total of 237 F3D-2s were built before production ended on 23 March 1952. A higher performance F3D-3 version with swept wings and J46 engines was planned, but was cancelled when the trouble-plagued J46 engine program was terminated.

Wikipedia: Douglas F3D Skyknight