Martin Marietta Model 845
{{Short description|US remotely piloted aircraft, 1972}}
| {{Infobox Aircraft Begin
|name=Model 845 |image= |caption= }}{{Infobox Aircraft Type |type=Communications relay drone |national origin=United States |manufacturer=Martin Marietta |designer= |first flight=April 1972 |introduced= |retired= |status= |primary user=United States Air Force |more users= |produced= |variants with their own articles= }} |
The Martin Marietta Model 845 was a remotely piloted aircraft developed in the United States in the late 1960s and early 1970s for use as a communications relay in the Vietnam War.
Design and development
Two prototypes were built as part of the United States Air Force's Compass Dwell program, these machines also being based on a Schweizer SGS 1-34 sailplane and similar in configuration to the competing XQM-93 design by Ling-Temco-Vought. Test flights began in April 1972; during testing, one of the prototypes stayed aloft for almost 28 hours,{{cite web|url=http://www.designation-systems.net/dusrm/app4/martin-845a.html|title=Martin Marietta 845A|last=Parsch|first=Andreas|year=2004|work=Directory of U.S. Military Rockets and Missiles Appendix 4: Undesignated Vehicles|publisher=Designation-Systems|accessdate=2017-11-09}} however it failed to meet the Air Force's requirement of a {{convert|40000|ft|m}} service ceiling.Aviation Week & Space Technology, Volume 98 (1973), [https://books.google.com/books?id=Oq4gAAAAMAAJ&q=%22Martin+Marietta+845%22 page 67] In 1973 The Model 845A was cancelled (along with the XQM-93), the program being replaced by Compass Cope.{{cite book|last=Robinson|first=Anthony|title=The Illustrated encyclopedia of aviation|volume=8|year=1979|publisher=Marshall Cavendish|location=London|isbn=978-0856855818|page=854}}
Surviving airframes
After the cancellation of the program, two 845 airframes were transferred by the Office of Naval Research to New Mexico Tech for use by the Langmuir Laboratory for Atmospheric Research, where they currently remain. Airframe 845A, which was converted into a piloted aircraft, was later used as a platform for atmospheric research. It continued flying as SPTVAR (Special Purpose Test Vehicle for Atmospheric Research) until the late 1990s. Its missions included flights over the Langmuir Laboratory facility in south-central New Mexico, flying through thunderstorms and making measurements of the electric field inside clouds.{{cite journal |last1=Winn |first1=William |title=Aircraft Measurement of Electric Field: Self-Calibration |journal=J. Geophys. Res. |date=20 April 1993 |volume=98 |issue=D4 |pages=7351–7365 |doi=10.1029/93JD00165|bibcode=1993JGR....98.7351W }} The other airframe, still configured as the original drone design, is in storage at the same facility.
Specifications (variant)
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|length in=4.75
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|span in=1.25
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|height in=6
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|eng1 number=1
|eng1 name=Lycoming TIO-360-A3B6
|eng1 type=horizontally opposed piston engine
|eng1 hp=200
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|endurance=28 hours
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See also
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References
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- This article contains material that originally came from the web article {{usurped|1=[https://web.archive.org/web/20110902194407/http://www.vectorsite.net/twuav.html Unmanned Aerial Vehicles]}} by Greg Goebel, which exists in the Public Domain.
External links
{{Martin aircraft}}
Category:1970s United States special-purpose aircraft
Category:Unmanned aerial vehicles of the United States
Category:Cancelled military aircraft projects of the United States
Category:Aircraft first flown in 1972
Category:Single-engined tractor aircraft