A Reaper drone crashed at the end of a New York runway last year because the operators mixed up the levers on the control panel, an Air Force investigation report released last week said.
The unmanned MQ-9A Reaper quickly lost power and hit the ground about a minute after its takeoff from Hancock International Airport in Syracuse, N.Y., resulting in a loss of over $6 million in government property, the Air Force accident investigation board headed by Lt. Col. Brian E. Prichard said.
The drone was assigned to the 174th Attack Wing and operated by the 108th Attack Squadron’s Launch and Recovery Element out of Hancock Field Air National Guard Base. The squadron is a training unit that produces newly qualified air crew, launch and recovery air crew, and instructor-qualified airmen for the Air National Guard and active Air Force.
The unit also launches and recovers drones that can be controlled from any other Reaper unit.
The incident happened on a clear Thursday afternoon June 25, 2020, after a crew launched the drone with plans to swap control to another crew once it reached military airspace at over 18,000 feet.
But the Reaper lost all engine power in 44 seconds, at about 150 feet, and was "significantly damaged" when it struck the end of the runway 21 seconds later, crashing into runway lights and spinning 180 degrees before stopping.
"Loss of engine power was due to the [pilot] misidentifying the Flap Lever," Prichard found. "Instead of pushing the Flap Lever forward to reduce the flaps, the [pilot] pulled the Condition Lever backwards which resulted in the fuel supply to the engine being cut off stopping the engine."
The two levers are an inch apart but have "very different functions," the report said.
The flap lever controls the orientation of the wing flaps, which are usually set at 15 degrees for takeoff, then retracted to 0 degrees by moving the lever to the middle or neutral position.
The condition lever controls the fuel shutoff valve, engine and the pitch of the propeller blades. When it’s fully forward, the engine operates normally, but at the midpoint, the fuel valve and engine shut off, and at fully back it stops the propeller blades.
The pilot continued to misidentify the levers after the engine lost power, mistakenly pulling the wing flaps all the way back, which pushed the aircraft down instead of letting it glide.
The pilot and the sensor operator were qualified, had logged hundreds of hours of flight time, including several recent sorties, and had the required amount of rest. But the board found that the pilot became fixated on the heads-up display during takeoff, which led to the lever mix-up.
The design of the ground control station console contributed to the crash, including the lack of a safety guard on the condition lever, the report said.
Despite being right next to each other, both have black handles and are unmarked or differentiated by color, the report said.
"These levers could easily be mistaken by an inexperienced, fatigued, or confused crewmember," Prichard wrote.