A stall because of insufficient airspeed caused the April 27 crash of a surveillance aircraft in southern Afghanistan that claimed the lives of pilot Brandon Cyr, a captain stationed at Scott Air Force Base, and three aircrew members, according to an accident investigation report released by the U.S. Air Force.
Cyr, 28, an experienced KC-135 air tanker pilot at Scott, had volunteered to serve as a pilot of the unarmed MC-12 Liberty surveillance plane in late 2012, and, after a training course, began serving in Afghanistan in early 2013.
Col. Pete Nezamis, the commander of 126th Air Refueling Wing, Cyr's former unit at Scott, said personnel assigned to the wing are still grieving Cyr's loss.
"He was very well-trained and highly motivated and very detailed," Nezamis said.
The MC-12 is an unarmed military version of the Beechcraft Super King, a twin-engine turboprop aircraft popular among business executives because of its reliability and fuel efficiency.
The low-flying MC-12 carries a sophisticated array of radios, sensors and video cameras to provide real time intelligence to American strike aircraft or ground troops about the location of enemy forces. The MC-12 began service in Iraq and Afghanistan since June 2009.
The April 27 accident that killed Cyr and his aircrew occurred because of a stall that occurred as Cyr's MC-12 was climbing into a left turn, which developed into a left spin followed quickly by a left spiral, from which the crew was unable to recover, according to the accident report.
Enemy fire was not a factor in the crash, according to the report.
Just before the crash, the MC-12 crew encountered cloudy conditions that reduced visibility and made it difficult to see the horizon. The air crew attempted to climb to an altitude where visibility would improve when the stall occurred, according to the report.