What happened
On June 3, 2018, a Textron Aviation Inc. LC41-550FG, registration OY-IPE, was conducting a private flight from Roskilde to the private airfield at Vejrø (EKVO). The pilot was aware that the available runway length at EKVO was critical, as the required landing distance was nearly equal to the available 550 meters, making the operation highly dependent on a sufficient headwind.
During the final approach to runway 24, at an altitude of approximately 300 feet, the aircraft encountered light turbulence and began to sink more rapidly than intended. The pilot attempted to correct this by increasing engine power, but the adjustment failed to sufficiently arrest the descent. Fearing a ground impact if power was increased further, the pilot elected to proceed with the landing rather than performing a go-around. The aircraft struck a dike area before the runway threshold with significant force. During the subsequent rollout, the nose wheel struck a stone and separated from the aircraft, leading to the accident. There were no fatalities or injuries among the two occupants.
The investigation
The Danish Accident Investigation Board examined the aircraft's performance data, the pilot's pre-flight calculations, and the software used for landing distance estimations. The investigation focused on why the pilot chose to continue the approach despite the unstable descent.
Investigators analyzed the pilot's use of an iPad-based software application for mass, balance, and landing distance calculations. They discovered significant discrepancies between this software and the aircraft's Pilot Operating Handbook (POH). Specifically, the app applied a 30% correction factor for grass runways, whereas the POH required a 60% increase in distance. Furthermore, the software failed to account for changes in total landing distance when calculating extended landing rolls.
Findings
- The operation was marginal due to the narrow margin between the required landing distance (522 m) and the available runway (550 m).
- The pilot's focus on touching down as early as possible to avoid overrunning the runway, combined with the unexpected sink rate, led to the hard landing.
- The use of inaccurate software calculations likely influenced the pilot's risk assessment, as the app suggested a shorter required distance than the POH indicated.
- The pilot's decision to continue the landing instead of aborting the approach was a contributing factor to the impact on the dike.
- The pilot had limited experience performing grass runway operations specifically with this aircraft type.
Safety action
- The developer of the iPad software application has been notified of the discrepancies between the app and the POH and has since released an update to correct these errors.