What happened
On April 3, 2023, a private Piper PA-28-235 was attempting a takeoff from the grass runway at Arnborg (EKAB) for a flight to Billund (EKBI). The flight was conducted under visual flight rules (VFR) in clear daylight. After completing engine checks, the pilot began the takeoff roll from the southern portion of the runway, specifically choosing a section of the strip that was clear of glider activity.
As the aircraft accelerated to approximately 40 mph, it began to veer unexpectedly to the right. The pilot attempted to correct this with left rudder input, which caused the aircraft to swing to the left. In an attempt to regain the centerline, the pilot applied opposing rudder, but the aircraft' and nose attitude began to drop. Although the aircraft briefly became airborne, it struck the ground heavily, first on the right main gear, then the left main gear, and finally the nose gear. The impact caused the nose gear strut to fail, resulting in the aircraft coming to rest on its nose with substantial damage to the airframe, including a deformed wing spar and bent propeller blades.
The investigation
The Danish Accident Investigation Board examined the runway conditions and the pilot's flight experience. Investigators found that while the grass in the takeoff area was short and firm, it contained significant patches of soft, moist moss that did not adhere well to the underlying soil.
Technical inspections of the Piper PA-28-235 confirmed the aircraft was airworthy and within weight and balance limits prior to the accident. The investigation also noted that the pilot had extensive experience as a glider pilot at this airfield but lacked recent or specific training for operations on soft grass surfaces, having not operated from such terrain since June 2022.
Findings
Several contributing factors led to the accident:
- The presence of soft, wet moss in the takeoff area, which compromised surface traction.
- The pilot's lack of specific training for operating on grass runways with soft conditions.
- The pilot's use of corrective rudder inputs that likely led to overcorrections during the takeoff roll.
- The decision to continue the takeoff attempt rather than aborting the roll when directional control was lost.
- A tendency to rely on previous experience from glider operations at the same airfield, which did not account for the specific challenges of the current surface conditions.