What happened
On 26 May 2008, an Extra 300/L, registration G-IIEX, was performing a transit flight from Southend Airport to Shoreham. The pilot, an experienced aerobatic instructor, decided to alter his route across the Kent coast to fly over low-lying ground near Ashford, driven by a desire to avoid worsening weather and a personal pressure to reach the home base.
As the flight progressed, visibility and cloudbase deteriorated. While attempting to execute a 180-degree turn to return to better conditions, the pilot instead turned through 270 degrees, inadvertently entering a valley with low cloud tops. Finding himself trapped by the terrain, the pilot decided to perform a precautionary landing in a field near Hastingsleigh. During the curving, downwind approach, the aircraft stalled at a low altitude, striking the ground with a right-wing first contact. The impact caused the aircraft to sustain extensive damage, leaving the pilot with a fractured wrist and the passenger with serious injuries, including spinal and skull fractures.
The investigation
The AAIB examined the wreckage and recovered data from a Garmin GPS unit. The investigation found that the aircraft's stall warning system and turn and slip indicator circuit breakers had been deactivated, likely to prevent nuisance warnings during aerobatic maneuvers. The investigation also analyzed the meteorological reports, noting that while early forecasts suggested improvement, later reports indicated much harsher conditions.
Medical specialists from the RAF Centre for Aviation Medicine reviewed the injuries. They noted that while the pilot's helmet prevented a major head injury, the passenger's lack of a helmet and the lack of energy-absorbing padding in the cockpit contributed to the severity of her injuries. The investigation also considered the aerodynamic impact of wet wings due to recent rain/drizzle.
Findings
- The pilot's decision to fly through deteriorating weather was influenced by a desire to avoid rain in the cockpit and pressure to complete the flight.
- The aircraft stalled during a downwind, curving approach at insufficient height for recovery.
- The deactivation of the stall warning circuit breaker meant the pilot received no warning of the impending stall.
- The aircraft's wings were wet, which may have increased the stall speed.
- The lack of energy-absorbing padding in the cockpit and the rigid seat mounting contributed to the passenger's spinal and head injuries.