What happened
On 18 May 2019, a Diamond DA42 Twin Star, registration G-SERE, was conducting a multi-engine training exercise at Cork Airport. The flight crew, consisting of an instructor and two students, had completed a flight to Shannon before returning to Cork for the final phase of their training. The exercise involved a simulated engine failure during a left-hand circuit.
During the downwind leg, the instructor reduced power to the left engine to simulate a failure. As the aircraft transitioned to the final approach, the crew noted an approach speed of approximately 110 knots, which was higher than typical for this maneuver. As the aircraft entered the flare for landing and power was reduced to idle, an audible warning sounded in the cockpit. The crew mistakenly identified this landing gear warning as a stall warning.
Because the landing gear had not been deployed, the aircraft touched down with the right wing low. This caused the right propeller blades to strike the runway surface. The instructor immediately took control, stabilized the aircraft, and brought it to a stop. There were no injuries to the three occupants, though the aircraft sustained significant damage to the propeller assemblies, engine cowlings, and boarding steps.
The investigation
The AAIU examined the flight sequence and the cockpit environment during the approach. The investigation established that the instructor was focused on managing the high approach speed and assisting the student pilot with the complexities of asymmetric thrust. This focus led to a distraction that prevented the completion of the landing checklist.
Investigators also reviewed the cockpit warnings. They found that the landing gear audible warning, which triggers when power is reduced below 25% while the gear is up, was misperceived by both the instructor and the student pilot as the stall warning. Furthermore, the investigation noted that the second student, acting as an observer in the rear seat, did not identify the missed landing gear extension.
Findings
- The primary cause of the incident was the failure to extend the landing gear due to non-adherence to standard operating procedures and checklist use.
- The instructor was distracted by the need to manage an unusually high approach speed and assist the student with the simulated engine failure.
- The crew misidentified the landing gear warning chime as a stall warning.
- The landing gear check was omitted from the flight sequence by both the pilot flying and the instructor.