What happened
On Tuesday, January 5, 1999, at 14:50, an amateur-built RH 001 (registration F-PDPZ) was involved in a ground excursion at Lannion aerodrome. The aircraft, operated for private purposes, was performing a local flight. Following a one-hour flight, the pilot attempted a landing on runway 11. This was the pilot's third landing attempt of the session.
As the aircraft exited the runway to the left at a very low speed, a sudden wind gust lifted the aircraft, causing it to depart the paved surface and enter the adjacent grassy area. The weather conditions at the time were characterized by CAVOK visibility, but with significant wind activity, recorded at 200 degrees at 12 knots with gusts reaching between 24 and 30 knots.
The investigation
The investigation focused on the aircraft's movement during the taxi phase following the landing. Investigators examined the meteorological conditions and the aircraft's handling during the turn. The pilot, who held a flight permit since 1965 and had accumulated 3,019 total flight hours (including 9 hours in the preceding three months), was experienced in operating aircraft with conventional landing gear.
Findings
- The primary cause of the excursion was the insufficient consideration of the effects of a tailwind during a low-speed ground turn.
- A sudden wind gust acted upon the aircraft while it was maneuvering at a very low velocity, causing the airframe to be lifted and veer off the taxiway.
- The aircraft sustained slight damage during the event.