What happened
On 22 June 2018, an Aerotechnik EV-97 Eurostar, registration G-LYNI, was conducting a general aviation flight from Spanish Point Airfield to Inishmore. During the approach to Inisheer Airport, the pilot decided to divert to the local airfield due to high temperatures within the cockpit.
While descending toward runway 31, the pilot maintained an idle throttle setting. As the aircraft neared the runway threshold, the pilot noticed the aircraft was low on the approach path and attempted to increase engine power. The engine failed to respond immediately to the throttle input. The aircraft touched down at the start of the paved surface and subsequently bounced. At the moment of the bounce, engine power increased suddenly. This surge in power, combined with a slight right crosswind and aerodynamic effects, caused the aircraft to veer left. The aircraft departed the runway, striking a raised area of sand dunes and a decommissioned PAPI light assembly, resulting in substantial damage to the nose gear, propeller, and engine cowling. The two occupants escaped the aircraft without injury.
The investigation
The AAIU examined the flight sequence, the mechanical state of the aircraft, and the environmental conditions. The investigation looked into the engine's lack of responsiveness during the final approach and the subsequent sudden increase in power. Investigators also reviewed the pilot's decision to land at Inisheer without prior permission, as the original landing permit was for Inishmore.
Findings
- The engine's failure to respond to throttle inputs during the approach may have been caused by vapour lock, potentially triggered by the long descent at idle power and the use of Mogas fuel.
- The sudden increase in power during the bounce, paired with a high angle of attack and low forward speed, created a leftward yawing tendency due to P-Factor, propeller torque, and prop-wash.
- A slight crosswind from the right likely contributed to the aircraft drifting leftward off the runway.
- The pilot landed at Inisheer without the required Prior Permission Required (PPR) status, as the permission had been obtained for Inishmore.