What happened
On April 25, 2020, a Beechcraft 35-C33A Debonair, registration OY-DNK, was performing a local VFR flight from Randers Airport (EKRD). The pilot intended to practice crosswind landings. Prior to engine start, the pilot observed wind conditions via a windsock and visual indicators, estimating a north wind of approximately 8 to 10 knots blowing across the runway.
During the takeoff roll on runway 07, the pilot applied full power. As the aircraft reached a speed of approximately 60 mph, it began to veer to the left. Although the pilot attempted to correct the deviation with right rudder input, the aircraft continued to drift leftward and began to slide sideways. The pilot subsequently reduced the throttle to idle, but the aircraft slid off the edge of the runway into the safety zone. Upon exiting the paved surface, the right main landing gear, nose gear, and left main landing gear collapsed sequentially. The aircraft came to a stop roughly 20 to 30 meters from the runway edge. There were no fatalities or injuries among the occupants.
The investigation
The investigation focused on the discrepancy between the pilot's perception of the wind and the actual environmental conditions. Investigators examined the aircraft's technical condition, mass and balance calculations, and meteorological data.
While the pilot's initial assessment suggested winds of 8–10 knots, the windsock at the time of the accident was fully extended, indicating a wind speed of approximately 15 knots. The investigation also reviewed the aircraft's maximum demonstrated crosswind capability, which is 17 knots. The technical condition of the Beechcraft 35-C33A Debonair and its weight and balance were found to be within limits and not contributing to the accident.
Findings
- A discrepancy between the perceived and actual wind speed led to insufficient rudder correction during the takeoff roll.
- The crosswind component during the takeoff roll was likely near the aircraft's maximum demonstrated crosswind limit of 17 knots.
- The aircraft's leftward drift may have been caused by the onset of the weathercock effect, which the pilot failed to counteract sufficiently due to the underestimated wind speed.
- The loss of directional control resulted in the aircraft sliding off the runway and the subsequent collapse of the landing gear.