What happened
On 24 February 2001, a Rockwell Commander 114, registration G-LIMA, was conducting a private cross-country flight from Shoreham to Biggin Hill. The flight, carrying the pilot and three passengers, proceeded normally until the aircraft approached the southern edge of the Gatwick Control Zone. During this period, the aircraft entered an area of falling snow and encountered a large cumulus cloud.
Radar tracking and eyewitness accounts indicate that the aircraft performed a very tight right turn near Sharpthorne. Witnesses observed the aircraft in a shallow descent, noting that the engine noise increased significantly. Shortly thereafter, the aircraft was seen to undergo a sudden structural failure; the left wing appeared to separate, and the aircraft entered a spin before impacting the ground. All four fatalities occurred during the impact, which destroyed the aircraft.
The investigation
AAIB investigators examined the wreckage and found extensive damage to the wing structure. Metallurgical analysis of the spar caps revealed that the fractures were caused by overload conditions rather than fatigue. The investigation focused on whether the aircraft's design or weight contributed to the failure. Calculations regarding the aircraft's weight and balance suggested it was likely near its maximum takeoff weight and center of gravity limits.
Investigators also analyzed the flight profile. While some witnesses reported seeing the wings flutter or vibrate unnaturally, subsequent reviews by the AAIB and the manufacturer concluded that the aircraft was not susceptible to aeroelastic flutter at its operating speeds. Instead, the evidence pointed toward a structural failure caused by excessive load factors during a high-speed manoeuvre.
Findings
- The aircraft entered a significant dive, possibly due to spatial disorientation while flying through falling snow or an attempt to avoid icing.
- To avoid ground impact, the pilot initiated an aggressive recovery manoeuvre.
- The descent provided sufficient altitude loss to allow the aircraft to accelerate beyond its design diving speed.
- The high-speed recovery manoeuvre generated enough load factor to cause the wing spar to fail.
- The aircraft was operating near its maximum allowable weight and center of gravity limits.