The U.S. Air Force Air Mobility Command has finished its investigation into the inflight detachment of the boom from a KC-10 aerial tanker on Nov. 1, 2016.
By Curimedia [CC BY 2.0], via Wikimedia Commons
Issues with the boom started during a training flight over Idaho when the tanker was about to refuel F-15s and a C-17.
The boom immediately began to move erratically and well outside of its operational and structural limits after the operator lowered it. Unable to control the boom, the aircraft declared an emergency and proceed to land at Mountain Home Air Force Base. The boom detached enroute to Mountain Home.
Investigators blamed a sheared Dual Rotary Voltage Transducer (DRVT) rotary crank as one of the primary cause of the incident. They also fault the boom operator from turning off the boom flight control switch in a timely manner.