What happened
On April 6, 2021, at 10:35 UTC, a Diamond DA42-NG, registration TC-SYN, operated by Ayjet Anadolu Yıldızları Hava Taşımacılığı ve Uçuş Eğitim Hizmetleri A.Ş., departed Hezarfen Airport (LTBW) for a cross-country flight to Balıkesir Koca Seyit Airport (LTFD). The flight was carrying an instructor, a student pilot, and two passengers.
Shortly after takeoff, the crew experienced an alternator failure in the right engine. Due to the inability to resolve the electrical issue, the crew requested an emergency return to Hezarfen Airport. During the landing on runway 23, the aircraft failed to decelerate sufficiently. The aircraft overran the end of the runway, traveling approximately 10 meters onto unpaved ground, where it struck a perimeter fence and a support pole. The impact caused light damage to the aircraft, specifically to the right propeller blade tips and the right wing leading edge.
The investigation
The UEİM investigation examined the aircraft's maintenance logs, pilot licenses, and weight and balance documentation. Investigators found that the aircraft's maintenance was up to date and that the crew's licenses and medical certificates were valid. Meteorological conditions at the time of the incident were found to be suitable for flight.
However, the investigation revealed significant discrepancies in the pre-flight weight and balance documentation. While the flight plan recorded a passenger weight of 235 kg and zero baggage, the actual weight of the passengers was 313 kg. The investigation noted that the lack of recorded baggage was inconsistent with the nature of the flight, which was intended for training purposes.
Findings
- The primary cause of the runway excursion was human error related to insufficient braking following the emergency landing.
- The aircraft was operating at a higher weight than documented due to inaccurate passenger weight recording.
- The necessity of an immediate return to the airport following the alternator failure meant the aircraft was landing at a higher weight than originally planned.
- Calm wind conditions contributed to the extended landing roll.
- The inaccurate weight and balance calculations were a contributing factor to the incident.