What happened
During a flight test for an FAA Private Pilot Licence at Humberside International Airport, a Cessna 421C Golden Eagle, registered G-SAIR, experienced a catastrophic sequence of events during a touch-and-go landing. Following a firm touchdown on Runway 21, the aircraft accelerated for takeoff. Just before rotation, both propellers struck the runway surface, creating visible puffs of smoke.
As the aircraft became airborne, it began to yaw and roll sharply to the left. The bank angle increased to approximately 90 degrees before the left wing tip struck the ground. The aircraft then cartwheeled across the grass, resulting in a post-impact fire. While the two pilots in the cockpit managed to escape, the flight examiner, seated in the passenger cabin, was unable to exit the burning wreckage and died from injuries sustained in the fire. The aircraft was destroyed.
The investigation
The AAIB investigation focused on why the propellers struck the runway and why the aircraft lost control. Examination of the runway revealed parallel strike marks from both propellers, indicating the aircraft was nearly wings-level when the impact occurred. The investigation found that the landing gear selector was in the 'UP' position.
Engineers discovered that the left propeller had a disconnected pitch-change link, causing one blade to rotate into a near-feathered position, which created significant drag and contributed to the left-side roll. The investigation also looked into the crew's roles, noting a lack of a formal pre-flight briefing regarding command responsaries, and examined the presence of promethazine in the pilot's blood, which had been taken as a sleep aid the previous night.
Findings
- The primary cause of the propeller strikes was the inadvertent retraction of the landing gear while the aircraft was still on the ground.
- It is believed that as the aircraft accelerated, the weight-on-wheels safety switch allowed the gear to be retracted, causing the aircraft to settle onto the runway.
- The loss of control was exacerbated by the significant drag produced by the damaged left propeller and the reduced climb performance due to extended flaps.
- Confusion regarding the roles of the pilot and the safety pilot contributed to the difficulty in managing the emergency.
- The presence of promethative in the pilot's system, while likely at a non-impairing level, could not be entirely ruled out as a contributing factor to performance.