Project Kingfisher was a weapons-development program initiated by the United States Navy during the latter part of World War II. Intended to provide aircraft and surface ships with the ability to deliver torpedoes to targets from outside the range of defensive armament, six different missile concepts were developed; four were selected for full development programs, but only one reached operational service. Background Project Kingfisher was initiated in August 1944, in response to the increasing difficulty of torpedo bomber aircraft to successfully complete attacks in the face of the increasing defensive firepower of ships during late World War II. The program was intended to produce standoff delivery systems to allow for the release of torpedoes from outside of the range of enemy defenses, specifically calling for "radar-controlled, subsonic, self-homing, air-borne missiles...to deliver explosive charge below water line of floating targets". Developed by the Bureau of Ordnance (BuOrd) and the National Bureau of Standards, under the direction of Hugh Latimer Dryden and Edward Conden. Kingfisher was derived from the Pelican and Bat guided-bomb projects, and produced a series of six different missile designs, designated 'A' through 'F', using a variety of payload and guidance options. Of these designs, four – Kingfisher C through F – were determined to be suitable for full development; due to the end of World War II, reducing the priority of the project, development was slowed, with flight testing of early, glider models of Kingfisher taking place in late 1946, and full development of the selected operational versions beginning during 1947. Variants Kingfisher A Kingfisher A, also known as SWOD (Special Warfare Ordnance Device) Mark 11, and later as SWOD Mark 15, was a glide bomb design, intended to carry a Mark 21 Mod 2 torpedo; the weapon was intended for use against surface targets in low-threat environments, where the attacking aircraft did not have to worry about defensive cover from fighter aircraft. Considered to be an interim design before fully powered missiles were available, the Kingfisher A design was used as a basis for glide tests to verify the aerodynamic properties of the Kingfisher family as a whole; these took place late in 1946 using the PB4Y-2 Privateer as a launch aircraft. The Kingfisher A itself was cancelled in early 1947 as no longer being required by the Navy, however the SWOD Mark 15 airframe design was used as a basis for the Kingfisher C. Kingfisher B