What happened
On 3 January 1999, a Socata TB 9, registration EI-FLY, was conducting a routine private flight for the purpose of building pilot experience. The flight departed from Weston Aerodrome with two pilots and one passenger on board. After performing general handling maneuvers and several touch-and-go landings, the pilot in the right-hand seat attempted a third circuit on Runway 25.
During the final approach, the pilot selected a high flap setting and reduced power to land. Upon touchdown, the aircraft struck the runway with enough force to bounce back into the air. In an attempt to maintain the runway heading, the pilot applied full power; however, the aircraft immediately slewed more than 90 degrees to the left. The aircraft veered toward the airfield perimeter, clipping trees before striking the ground at the nearby Lucan Golf Club. The impact caused the aircraft to cartwheel, tearing the engine and port wing from their mounts, eventually leaving the fuselage inverted on a fairway.
All 3 occupants of the aircraft sustained serious injuries. The two pilots were trapped in the overturned cabin for over an hour, during which they were exposed to dripping aviation fuel, resulting in chemical burns. An ambulance crewman who entered the cockpit to check the pilots also sustained chemical burns to his leg.
The investigation
Investigators examined the aircraft's mechanical systems to determine if a malfunction contributed to the loss of control. The inspection of the flap system indicated that the flaps were likely at a high deflection setting prior to impact. The investigation also focused on the rudder and nose-wheel steering mechanism.
Evidence showed significant damage to the forward bulkhead and the nose-wheel steering connecting rods. Specifically, the connecting lever arm was found broken, and the rudder was found deflected hard to the right. Testing on a similar aircraft type confirmed that applying full power at various flap settings caused the nose to yaw upward and to the left, which would exacerbate a leftward turn.
Findings
- The primary cause of the accident was the severity of the initial impact on the runway, which resulted in the loss of directional control.
- The damage to the rudder and steering linkage prevented the pilot from correcting the sharp leftward veer following the bounce.
- The aircraft's tendency to yaw left when full power is applied at high flap settings contributed to the uncontrollable turn.
- The practice of pilots not qualified as instructors flying from the right-hand seat was identified as an unsafe practice.
- The injury to the rescue personnel highlighted the need for fire services to use full protective equipment when approaching aircraft involving fuel leaks.