The Radioplane BTT, known as RP-71 by the company, as WS-426/2 by the
United States Navy
The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...
, and as WS-462/2 by the
US Air Force
The United States Air Force (USAF) is the Air force, air service branch of the United States Department of Defense. It is one of the six United States Armed Forces and one of the eight uniformed services of the United States. Tracing its ori ...
, is a family of
target drone
A target drone is an unmanned aerial vehicle, generally remote controlled, usually used in the training of anti-aircraft crews.
One of the earliest drones was the British DH.82 Queen Bee, a variant of the Tiger Moth trainer aircraft operation ...
s produced by the
Radioplane Company
The Radioplane Company was an American aviation company that produced drone aircraft primarily for use as gunnery targets. During World War II, they produced over 9,400 of their Radioplane OQ-3 model, a propeller-powered monoplane, making it th ...
(later a division of
Northrop).
History
In the post-World War II period, Radioplane followed up the success of the
OQ-2 target drone with another very successful series of piston-powered target drones, what would become known as the Basic Training Target (BTT) family (the BTT designation wasn't created until the 1980s, but is used here as a convenient way to resolve the tangle of designations). The BTTs remained in service for the rest of the 20th century.
Variants
OQ-19 / KD2R

The BTT family began life in the late 1940s, evolving through a series of refinements with the
US Army
The United States Army (USA) is the primary land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of the United Stat ...
designations of OQ-19A through OQ-19D, and the US Navy name of Quail with designated KD2R. Early models had a metal fuselage and wooden wings, but production standardized on an all-metal aircraft.
Radioplane developed an experimental XQ-10 variant that was mostly made of plastic, but although evaluations went well, it wasn't considered a major improvement over existing technology, and it did not go into production.
Radioplane was bought out by
Northrop in 1952 to become the Northrop Ventura Division, though it appears that the "Radioplane" name lingered on for a while.
MQM-33 / MQM-36
In 1963, when the US military adopted a standardized designation system, the surviving US Army BTT variants became MQM-33s and the KD2R-1, the only member of the family still in Navy service, became the MQM-36 Shelduck.
The MQM-36 was the most evolved of the BTT family, but retained the same general configuration as the other members. It was larger and more sophisticated than the first-generation OQ-2A series, and was powered by a more powerful flat-four four-stroke
McCulloch piston engine with . The MQM-36 carried
Luneburg lens
A Luneburg lens (original German ''Lüneburg-Linse'') is a spherically symmetric gradient-index lens. A typical Luneburg lens's refractive index ''n'' decreases radially from the center to the outer surface. They can be made for use with electrom ...
radar enhancement devices in its wingtips that generated a
radar signature of a larger aircraft. The radar reflectors (Luneburg lens) wasn't used by the US Navy as the air search radar interfered with the control signals. Thus the air search radar was not used.
Launch was by
RATO booster or bungee catapult, and recovery by parachute.
MQM-57 Falconer
A variant of the BTT designated the RP-71, also known as the SD-1 Observer and later redesignated MQM-57 Falconer, was built for battlefield reconnaissance, with first flight in 1955. The Falconer was similar in appearance to the Shelduck, but had a slightly longer and stockier fuselage. It had an autopilot system with radio-control backup, and could carry cameras, as well as illumination flares for night reconnaissance. Equipment was loaded through a hump in the back between the wings. Although it only had an endurance of a little more than a half-hour, making it of limited use, about 1,500 Falconers were built and the type was used internationally with several different military forces, remaining in service into the 1970s.
Over 76,000 BTT targets were built in all – more than any other type of aircraft – and the type was used by at least 18 nations.
Operators
;
*
British Army
The British Army is the principal Army, land warfare force of the United Kingdom. the British Army comprises 73,847 regular full-time personnel, 4,127 Brigade of Gurkhas, Gurkhas, 25,742 Army Reserve (United Kingdom), volunteer reserve perso ...
Surviving aircraft

;Australia
* N10-53152 – KD2R-5 on display at the
South Australian Aviation Museum in
Port Adelaide, South Australia
Port Adelaide is a port-side region of Adelaide, approximately northwest of the Adelaide city centre, Adelaide CBD. It is also the namesake of the City of Port Adelaide Enfield council, a suburb, a federal and state electoral division and is t ...
.
;Netherlands
* KL-110 – KD2R-5 on display at the
Nationaal Militair Museum in
Soesterberg, Utrecht.
;Sweden
* KD2R-5 on display at the
Arboga Missile Museum.
* On display at the Kolmårdens Djurpark outside of
Norrköping, Östergötland.
;United Kingdom
* XR346/XV383/XW578 – D.1 on display at the
Bournemouth Aviation Museum in
Hurn, Dorset.
* XT581 – SD-1 on display at the
Imperial War Museum Duxford
Imperial War Museum Duxford, also known as IWM Duxford or simply Duxford, is a branch of the Imperial War Museum near Duxford in Cambridgeshire, England. Duxford, Britain's largest aviation museum, houses exhibits, including nearly 200 aircraf ...
in
Duxford, Cambridgeshire. It was given to the museum in 1978 by the British Army and was restored in the 1990s.
;United States
* KD2R on display at the
Aviation Unmanned Vehicle Museum in
Caddo Mills, Texas. It includes the complete communications hardware.
* KD2R-5 on display at the
Western Museum of Flight in
Torrance, California
Torrance is a coastal city in the Los Angeles metropolitan area located in southwestern Los Angeles County, California, United States. The city is part of what is known as the South Bay (Los Angeles County), South Bay region of the metropolitan ...
.
* MQM-33 on display at the
Estrella Warbirds Museum in
Paso Robles, California.
* MQM-33 on display at the U.S. Veterans Memorial Museum in
Huntsville, Alabama
Huntsville is the List of municipalities in Alabama, most populous city in the U.S. state of Alabama. The population of the city is estimated to be 241,114 in 2024, making it the List of United States cities by population, 100th-most populous ...
.
* MQM-33 on display at the
Canadian Museum of Flight in
Langley, British Columbia.
* MQM-57 on display at the
National Museum of the United States Air Force
The National Museum of the United States Air Force (formerly the United States Air Force Museum) is the official museum of the United States Air Force located at Wright-Patterson Air Force Base, northeast of Dayton, Ohio. The NMUSAF is ...
in
Dayton, Ohio
Dayton () is a city in Montgomery County, Ohio, United States, and its county seat. It is the List of cities in Ohio, sixth-most populous city in Ohio, with a population of 137,644 at the 2020 United States census, 2020 census. The Dayton metro ...
.
* OQ-19 fuselage in storage at the
National Air and Space Museum
The National Air and Space Museum (NASM) of the Smithsonian Institution is a museum in Washington, D.C., in the United States, dedicated to history of aviation, human flight and space exploration.
Established in 1946 as the National Air Museum, ...
in
Washington, D.C.
Washington, D.C., formally the District of Columbia and commonly known as Washington or D.C., is the capital city and federal district of the United States. The city is on the Potomac River, across from Virginia, and shares land borders with ...
* OQ-19 on display at the National Model Airplane Museum in
Muncie, Indiana
Muncie ( ) is a city in Delaware County, Indiana, United States, and its county seat. It is located in East Central Indiana about northeast of Indianapolis. At the 2020 census, the city's population was 65,195, down from 70,085 in the 2010 c ...
.
* OQ-19A on display at the
Air Victory Museum in
Lumberton, New Jersey.
* OQ-19B on display at the
Alaska Aviation Museum in
Anchorage, Alaska
Anchorage, officially the Municipality of Anchorage, is the List of cities in Alaska, most populous city in the U.S. state of Alaska. With a population of 291,247 at the 2020 United States census, 2020 census, it contains nearly 40 percent of ...
.
* OQ-19D on display at the National Museum of the United States Air Force in Dayton, Ohio.
* OQ-19D on display at the Alaska Veterans Museum in
Anchorage, Alaska
Anchorage, officially the Municipality of Anchorage, is the List of cities in Alaska, most populous city in the U.S. state of Alaska. With a population of 291,247 at the 2020 United States census, 2020 census, it contains nearly 40 percent of ...
.
* OQ-19D on display at the
Pima Air & Space Museum
The Pima Air & Space Museum is an aerospace museum in Tucson, Arizona, US. It features a display of nearly 400 aircraft spread out over on a campus occupying . It has also been the home to the Arizona Aviation Hall of Fame since 1991.
Overv ...
in
Tucson, Arizona
Tucson (; ; ) is a city in Pima County, Arizona, United States, and its county seat. It is the second-most populous city in Arizona, behind Phoenix, Arizona, Phoenix, with a population of 542,630 in the 2020 United States census. The Tucson ...
.
* OQ-19D on display at the Minnesota Wing of the
Commemorative Air Force
The Commemorative Air Force (CAF), formerly known as the Confederate Air Force, is an American non-profit organization based in Dallas, Texas, that preserves and shows historical aircraft at Air show, airshows, primarily in the U.S. and Canada.
...
in
South St. Paul, Minnesota.
* OQ-19D on display at the
Greater Saint Louis Air & Space Museum in
Cahokia Heights, Illinois.
Specifications (MQM-36)
References
Citations
Bibliography
*
*
Taylor, John W. R. ''Jane's All The World's Aircraft 1966–67''. London: Sampson Low, Marston & Company, 1966.
*This article contains material that originally came from the web article by Greg Goebel, which exists in the Public Domain.
{{US Army drones
BTT
1950s United States special-purpose aircraft
Target drones of the United States
High-wing aircraft
Single-engined tractor aircraft