What happened
On 4 May 2018, a microlight aircraft, registration EI-EOH, departed Lough Conn airfield in Co. Mayo for a local flight. After performing a touch-and-go landing, the aircraft climbed and navigated toward the Slieve Gamph/Ox Mountain range. While flying at approximately 1,000 feet, the aircraft suddenly rolled to the left and entered a steep, descending turn. The aircraft impacted the ground in a near-vertical, nose-down attitude. The 1 fatal occupant, the pilot, was killed upon impact, and the aircraft was destroyed.
The investigation
The AAIU investigation utilized GPS data, witness accounts, and critical video footage from a cockpit-mounted camera to reconstruct the flight. Investigators examined the aircraft's maintenance records, which showed the Rotax 912ULS engine and the airframe were well-maintained and in good working order. Meteorological conditions at the time were favorable, with clear visibility and light winds.
Analysis of the wreckage and impact site confirmed the aircraft struck the ground with its left wing first, consistent with a descending left-hand turn. The investigation also ruled out carbon monoxide poisoning, as cockpit detectors showed no signs of chemical change and post-mortem tests were negative. While the pilot was taking medication for blood pressure and cholesterol, medical records indicated he was asymptomatic and had passed all necessary medical examinations.
Findings
- The aircraft and engine were mechanically sound and functioning normally until the moment of impact.
- There was no evidence of flight control failure or mechanical malfunction.
- The pilot was properly licensed and medically certified for the flight.
- The pilot became unconscious during flight, as captured by cockpit video, causing the aircraft to depart from level flight and enter a fatal descent.
- The specific medical cause for the loss of consciousness could not be determined through the post-mortem examination.