NSRDC BQM-108
Tethered VTOL demonstrator canceled before free flight.
The U.S. Navy’s NSRDC BQM-108 was a 1970s experimental unmanned aerial vehicle built to test a vertical takeoff and landing (VTOL) concept known as “Vertical Attitude Take-Off and Landing” (VATOL), or tailsitter flight. The project aimed to show that remotely piloted aircraft could operate from ships with limited deck space, as the Navy wanted to spread aviation assets across more vessels to counter the growing cruise missile threat.
The XBQM-108A prototype was based on the MQM-74 Chukar target drone. It received a delta wing and canard control surfaces, plus a thrust vectoring system that used vanes to redirect engine exhaust. The drone kept the Chukar’s recovery parachute and radio guidance, and added a radar altimeter along with a midcourse guidance unit borrowed from the AGM-84 Harpoon anti-ship missile.
On September 29, 1976, the XBQM-108A made its first tethered flight, drawing fuel from 42-gallon drums through the tether. The test succeeded, proving the VATOL profile could work for unmanned vehicles. However, the project was canceled before any free flights or transitions to horizontal flight could occur.
Quick Facts
- Aircraft Type
- Unmanned aerial vehicle
- National Origin
- United States
- Manufacturer
- Naval Weapons Center
- Primary User
- United States Navy
- Number Built
- 1
- First Flight
- 29 September 1976
- Developed From
- BQM-74 Chukar
Facts from the source article.
Lore & Background
The XBQM-108 project began in 1975 under the U.S. Navy's David W. Taylor Naval Ship Research and Development Center. The Navy believed that the increasing threat from cruise missiles required aviation assets to be dispersed among more ships, which had limited space compared to aircraft carriers. The XBQM-108A was modified from the MQM-74 Chukar target drone, receiving a revised delta wing with canard control surfaces and a thrust vectoring system using vanes to deflect engine exhaust. It retained the Chukar's recovery parachute and radio guidance, adding a radar altimeter and a midcourse guidance unit derived from the AGM-84 Harpoon anti-ship missile.
The XBQM-108A conducted its first tethered flight on September 29, 1976, using fuel supplied through the tether from 42 US gallon drums. The flight was successful and demonstrated that the VATOL flight profile for unmanned vehicles was practical. However, the project was canceled before further testing could occur; the vehicle never conducted free flights or transitions to horizontal flight.
Reader's Guide
The NSRDC BQM-108 (XBQM-108A) represents a focused but curtailed effort by the U.S. Navy to explore vertical attitude takeoff and landing for unmanned systems. Its development was driven by a strategic concern: the need to operate aviation assets from smaller ships without runways, in response to the cruise missile threat. The successful tethered flight in 1976 proved the VATOL concept workable for remotely piloted vehicles, but the project's cancellation before free flights left the concept unvalidated in full operational conditions. The aircraft's design—a modified Chukar drone with delta wing, canards, and exhaust vanes—shows a pragmatic approach to adapting existing hardware for novel flight regimes. Its legacy is that of a proof-of-concept that reached the threshold of free flight but never crossed it, leaving the tailsitter approach for unmanned vehicles largely unexplored until later decades.
Did You Know?
- It used a thrust vectoring system with vanes that deflected the engine's exhaust.
- Its first and only flight was tethered, with fuel supplied from 42 US gallon drums.
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