Pilot’s Decision To Attempt Takeoff With Frost Covering The Airplane’s Wings

Location: Taylor, Arizona Accident Number: WPR24FA052
Date & Time: December 6, 2023, 07:44 Local Registration: N449RA
Aircraft: Remos Aircraft GmbH Remos GX Aircraft Damage: Substantial
Defining Event: Loss of control in flight Injuries: 1 Serious
Flight Conducted Under: Part 91: General aviation - Personal

Analysis: The pilot of the light sport airplane was preparing to depart for a cross-country flight. A witness reported that when he arrived at the airport that morning, he saw the airplane on the parking ramp, not moored down, and the engine was running. As the airplane taxied through the ramp area, he saw that it was covered with frost. Soon after the witness had gone inside the airport office, he was notified from an airplane flying over the airport that an airplane had crashed on the runway. A photo of the accident site minutes after the accident revealed that the upper surfaces of the horizontal stabilizers were covered in frost.

Postaccident examination of the airframe and engine revealed no evidence of any preimpact mechanical malfunction or failure that would have precluded normal operation. Based on the witness’s statement and photo evidence, the airplane likely had frostcontaminated wings, which the pilot did not remove before takeoff. His subsequent rotation of the airplane during takeoff with its lift capability degraded due to contamination of its flying surfaces resulted in exceedance of the airplane’s critical angle of attack, an aerodynamic stall, and subsequent impact with the ground.

Probable Cause and Findings: The National Transportation Safety Board determines the probable cause(s) of this accident to be -- The pilot’s decision to attempt takeoff with frost covering the airplane’s wings, which led to an exceedance of the airplane’s critical angle of attack and an aerodynamic stall. 

FMI: www.ntsb.gov