McDonnell TD2D Katydid

Lore & Background

In March 1941, the U.S. Navy awarded McDonnell Aircraft a contract for a radio-controlled target drone under the designation XTD2D-1. The aircraft featured a mid-mounted wing, V-tail, and a McDonnell XPJ40-MD-2 pulsejet engine mounted atop the rear fuselage. It could be launched by catapult from the ground or from underwing racks on Consolidated PBY Catalina flying boats. The drone was gyro-stabilized and controlled by radio command; at the end of its mission it could be recovered by parachute.

The Katydid entered service in 1942, with testing conducted at the Naval Air Missile Test Center in Point Mugu, California. Production models were originally designated TD2D-1, but the Navy changed its designation system in 1946, redesignating the XTD2D-1 and TD2D-1 as XKDD-1 and KDD-1, respectively. Later that year, the Navy changed McDonnell's manufacturer code letter from 'D' to 'H', resulting in the KDD-1 being redesignated as KDH-1.

Reader's Guide

The McDonnell TD2D Katydid served as a dedicated target drone for the United States Navy from 1942 into the late 1940s, providing realistic training for anti-aircraft and aerial gunnery crews. Its pulsejet powerplant, while noisy and inefficient for manned aircraft, was well-suited for a disposable or recoverable drone, offering simplicity and high speed. The drone's ability to be launched from both ground catapults and PBY Catalina flying boats increased its operational flexibility. The Katydid's design incorporated gyro-stabilization and radio control, allowing it to simulate enemy aircraft maneuvers. Its recovery by parachute enabled reuse, reducing costs. The multiple redesignations—from TD2D-1 to KDD-1 to KDH-1—reflect the Navy's evolving aircraft designation system and the need to distinguish McDonnell from Douglas Aircraft. A surviving KDH-1 is displayed at the Steven F. Udvar-Hazy Center of the National Air and Space Museum, donated by the U.S. Navy in 1966, preserving the legacy of this early pulsejet drone.