What happened
On 14 August 2023, an ATR 72-212A-600, registration EI-HDK, was performing a commercial passenger flight from Dublin to Liverpool Airport. The flight had been delayed due to a previous technical issue involving pitot heat, resulting in a departure approximately 90 minutes behind schedule.
During the approach to Runway 09, the crew encountered heavy rain showers. While the aircraft was initially stable, the intensity of the rain increased significantly as the aircraft crossed the runway threshold. This sudden weather change caused visibility to drop to near zero. As the aircraft passed 50 ft above the ground, the airspeed decreased and the vertical descent rate failed to reduce, leading to a hard landing with a recorded vertical acceleration of 2.8 g. The commander immediately took control and initiated a missed approach. A subsequent landing attempt on Runway 27 was completed without further incident.
The investigation
The AAIB examined the flight data recorder (FDR) and cockpit voice recorder (CVR) to reconstruct the sequence of events. The CVR confirmed the crew's account of the rapidly deteriorating visibility and the sudden impact. The FDR analysis showed that while the aircraft was in a stable descent until 1,000 ft, a change in wind conditions occurred near the threshold.
Technical analysis of the aircraft following the incident led the manufacturer to recommend the replacement of both main landing gear assemblies. No physical defects were found on the aircraft, and it returned to service in late August 2023.
Findings
- The primary cause of the hard landing was the aircraft encountering increasing tailwind and heavy rain as it crossed the runway threshold.
- The sudden reduction in visibility likely prevented the crew from visually detecting that the rate of descent was not being properly managed during the flare.
- The aircraft's airspeed decayed during the encounter with the heavy rain, and the vertical speed did not decrease sufficiently before touchdown.
- Meteorological reports and flight management system calculations indicated that the wind direction shifted, providing an increasing tailwind component at the moment of impact.