Accident Details
Probable Cause and Findings
The pilot’s decision to attempt takeoff with frost covering the airplane and rotating below the published rotation speed, which led to exceedance of the airplane’s critical angle of attack and an aerodynamic stall.
Aircraft Information
Registered Owner (Current)
Analysis
On December 28, 2020, about 1945 central standard time, a Beech 65-A80-8800, N134BA, was substantially damaged when it was involved in an accident near Alexandria, Minnesota. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 135 on-demand cargo flight.
The pilot reported that he performed a preflight inspection of the airplane and that it was free of frost. While loading the airplane with cargo, he determined that the airplane would be over its maximum gross weight limit of 8,800 pounds, so he elected to not load one 120-pound package to stay under the gross weight limit. In separate reports and interviews, the pilot stated that he rotated the airplane on takeoff between 82 and 85 knots.
When the airplane was about 20-30 ft in the air, with the landing gear extended, it turned sharp to the right and the pilot corrected by applying aileron and rudder. The pilot reported that within a few seconds the airplane started to shake, and it entered a steep descent to the left; the left wing hit the ground. He did not hear a stall warning horn. The airplane bounced slightly to the right and the right landing gear collapsed. The left wing sustained substantial damage.
The airplane came to rest about 4,000 ft from the start of the runway and about 600 ft left of the runway centerline. The flaps were retracted, and the landing gear was in the down position.
The police report of the accident indicated that the pilot told the responding officer immediately after the accident that there could have been some frost on the wings of the airplane. The airport manager who responded to the accident scene reported that all the airplane surfaces were covered with frost when he arrived a short time after the accident.
A checklist found within the accident airplane listed a rotation speed of 83 knots for takeoff weight below 8,000 pounds and 96 knots for 8,800 pounds. Review of the Owner’s Manual applicable to the accident airplane revealed a listed takeoff rotation speed at the maximum gross weight of 8,800 pounds as 96 knots. The stall speed chart indicated that the maximum gross weight power-on stall speed with landing gear and flaps retracted was 91 knots, and the power-on stall speed with the landing gear and flaps extended was 78 knots. There was no stall speed chart for an airplane configured with the flaps retracted and the landing gear extended.
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# CEN21LA101