Project Kingfisher
U.S. Navy program to develop standoff torpedo-delivery missiles.
Project Kingfisher was a U.S. Navy weapons program that began in August 1944. It aimed to let aircraft and surface ships launch torpedoes from beyond the reach of enemy defensive guns. Six missile designs were proposed; four moved into full development, but just one was ever used in service.
The program responded to the growing difficulty torpedo bombers faced against improved shipboard defenses late in World War II. It called for radar-guided, subsonic, self-homing missiles that could deliver an explosive charge below a target’s waterline. The Bureau of Ordnance and the National Bureau of Standards oversaw the work, with Hugh Latimer Dryden and Edward Condon directing it. Kingfisher grew out of the earlier Pelican and Bat guided-bomb projects. The six designs were labeled A through F, with different payloads and guidance systems. Four—C through F—were chosen for full development. The war’s end lowered the project’s priority, slowing progress. Glider models were flight-tested in late 1946, and full development of the operational versions began in 1947.
Kingfisher A, also called SWOD Mark 11 and later SWOD Mark 15, was a glide bomb meant to carry a Mark 21 Mod 2 torpedo. It was intended for low-threat environments where enemy fighters were not a concern. Seen as an interim step before powered missiles arrived, its airframe was used for glide tests in late 1946, launched from a PB4Y-2 Privateer. The Navy canceled it in early 1947 as no longer needed, but the SWOD Mark 15 design later served as the basis for Kingfisher C.
Kingfisher B, or SWOD Mark 21, was similar to Kingfisher A but lighter—only two-thirds the weight of the Bat bomb. Its payload was a plunge bomb, an unguided projectile that would glide briefly, then sink alongside a target and detonate underwater. It was unpowered and canceled in 1947 for not meeting requirements.
Kingfisher C was the only variant to enter service. Developed from the SWOD Mark 15 airframe, it received the designation AUM-N-2 Petrel. Fairchild Aircraft’s Guided Missiles Division built it. The Petrel was essentially a Mark 21 Mod 2 torpedo fitted with wings and a Fairchild J44 turbojet. It had a range of 20 nautical miles at Mach 0.5 and used semi-active radar homing. It entered service in 1956, by which time its warhead had been changed to the Mark 41 torpedo.
Quick Facts
- Is Missile
- yes
- Origin
- United States
- Used By
- United States Navy
- Service
- 1956–1959
- Designer
- National Bureau of Standards
- Design Date
- 1944–1956
Facts from the source article.
Lore & 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 allowing release of torpedoes from outside 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 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. It produced six different missile designs, designated 'A' through 'F', using a variety of payload and guidance options. Of these, four—Kingfisher C through F—were determined 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 taking place in late 1946, and full development of selected operational versions beginning during 1947.
The variants included Kingfisher A (SWOD Mark 11/15), a glide bomb carrying a Mark 21 Mod 2 torpedo, cancelled in early 1947; Kingfisher B (SWOD Mark 21), a lightweight design with a plunge bomb payload, also cancelled in 1947; Kingfisher C (AUM-N-2 Petrel), the only member to reach operational service, essentially a Mark 21 Mod 2 torpedo fitted with flying surfaces and a Fairchild J44 turbojet, with a range of 20 nmi at Mach 0.5 using semi-active radar homing; Kingfisher D (AUM-N-4 Diver), intended to use a novel dual-purpose rocket propulsion system, cancelled due to complexity; Kingfisher E (SUM-N-2 Grebe), the only surface-launched variant, intended to deliver a Mark 41 torpedo from ships, cancelled as sonar systems of the time were incapable of detecting targets at sufficient range; and Kingfisher F (AUM-N-6 Puffin), a powered version with a pulsejet engine and active radar homing, cancelled in October 1949.
Reader's Guide
Although Project Kingfisher largely failed to result in the operational weapons it had been intended to produce, with only Kingfisher C, the AUM-N-2 Petrel, seeing operational service, much was learned about the issues of aerodynamics and control of guided weapons. The U.S. Navy chose to use fully ballistic rocket-powered weapons for antisubmarine use, developing the RUR-5 ASROC as its standard anti-submarine missile. However, the concept of an unpiloted torpedo-carrying aircraft-type missile was developed by other nations, with the French Malafon missile and Australian Ikara being markedly similar in concept to the Kingfisher E/Grebe. Petrel entered operational service in 1956, launched by the P2V Neptune patrol aircraft, but was withdrawn from operational use by 1959, as it was useless against submerged submarines and the U.S. Navy placed a low priority on defense against surface vessels. Surviving Petrels were repurposed as target drones, redesignated as AQM-41A shortly before leaving service in the early 1960s.
Did You Know?
- Only one of the six Kingfisher designs, the AUM-N-2 Petrel, reached operational service.
- The Kingfisher E (Grebe) was the only surface-launched variant, cancelled due to sonar limitations.
- Surviving Petrel missiles were repurposed as target drones and redesignated AQM-41A.
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