Accident Summary
On 3 April 2024, at approximately 0939 local time, a Bell TH-1H helicopter (Tail Number 74-22313) assigned to the 23d Flying Training Squadron, 58th Special Operations Wing, experienced a dynamic rollover event while conducting training at Skelly Stagefield Army Heliport, Alabama. The aircraft carried four personnel: a Mishap Instructor Pilot (MIP) and three Mishap Student Pilots (MSP1, MSP2, and MSP3). The students were enrolled in Helicopter Undergraduate Pilot Training and were performing a Transition Checkride, a flight designed to evaluate student progress after three sorties in the aircraft.
Sequence of Events
During slope operations, MSP1 initiated takeoff with the left skid rising from the ground. MSP1 perceived the helicopter as level when it was actually in a 2-5 degree right bank. Believing the helicopter was sliding left, MSP1 increased right bank to correct the perceived slide, resulting in a 6-10 degree right-banked attitude. The MIP attempted a left control input to counter MSP1's right roll, but this was ineffective.
MSP1 then perceived the slide had stopped and the helicopter was level, though it remained at a 6-10 degree right bank. MSP1 increased power to lift off, causing the helicopter to roll right and the main rotor blade to strike the ground. The impact resulted in a rollover of the aircraft.
Injuries and Damage
The four personnel aboard sustained minor injuries. The TH-1H helicopter suffered severe damage.
Cause
The Board President determined, by a preponderance of the evidence, that the mishap was caused by MSP1 becoming disoriented coupled with insufficient corrective action by the MIP. MSP1 falsely perceived the aircraft as level when it was in a right bank, leading to erroneous control inputs and attempting takeoff from a right bank. This created a rolling motion that caused the main rotor blade to contact the ground and the helicopter to roll over. The MIP failed to apply sufficient corrective action by not reducing power.