Accident Overview
A twin-engine cargo airplane, conducting a routine night flight, experienced an aerodynamic stall shortly after takeoff. Witnesses and radar data indicated the aircraft accelerated to a maximum ground speed of 97 knots during its takeoff roll, followed by a steep climb. The airplane then leveled off briefly before pitching down and impacting a parallel taxiway with its landing gear retracted.
Investigation Findings
Postaccident examination revealed that both engines were operating at impact, evidenced by slash marks on the taxiway pavement and rotation signatures on the remaining propeller blades. No preimpact mechanical failures or malfunctions were found in the airframe or either engine. The cargo was positioned within the normal weight and balance envelope, with no indication of cargo shift. The elevator trim jackscrew was found in a neutral pitch trim setting.
Climb Performance
The manufacturer's prescribed takeoff procedure required accelerating to 85 knots, then increasing pitch to achieve a climb angle allowing acceleration past 96 knots, with landing gear retraction scheduled after exceeding 128 knots. Based on the loading and environmental conditions, the airplane's calculated climb performance was 1,800 feet per minute. Applying the prevailing wind conditions to the radar-observed ground speed yielded a maximum estimated airspeed of 111 knots. The airplane briefly achieved a climb rate exceeding 3,000 feet per minute before leveling off.
Stall Indications
After leveling, the aircraft decelerated and began descending. This profile suggested the airplane likely entered an aerodynamic stall during the initial climb. The sequence of events—aggressive climb, leveling, deceleration, and descent—is consistent with a stall event.
Probable Cause
The pilot’s failure to maintain adequate airspeed during the initial climb, which resulted in an aerodynamic stall and subsequent impact with the ground.