What happened
On 9 September 2012, a Corben Junior Ace, registration G-BSDI, was performing a solo private flight departing from a small grass airstrip located approximately 4 nautical miles southwest of Bath. The airfield featured a runway oriented 06/24, measuring 520 metres in length and 30 metres in width. Weather conditions at the time of departure were generally good, with winds from 150° at 9 knots, though gusts up to 25 knots were anticipated later in the day.
During the initial climb, the aircraft performed normally until reaching an altitude of approximately 65 feet. At this point, the aircraft encountered a sudden gust of wind that caused a significant pitch-up and a left roll. Shortly after this upset, the left wing dropped, resulting in a bank angle of roughly 70° and a rapid loss of altitude. The aircraft subsequently struck a ploughed field in a nose-down attitude and cartwheeled. The pilot sustained minor injuries, which were attributed to the aircraft's steel frame construction and the use of a full safety harness.
The investigation
The investigation was based on the aircraft accident report submitted by the pilot. Analysis of the pilot's GPS navigation unit provided critical data, revealing a sharp decrease in groundspeed from 47 knots to 33 knots immediately preceding the impact. This data supported the conclusion that the aircraft had entered a stall following the atmospheric disturbance.
Findings
- The aircraft encountered a sudden wind gust during the climb phase.
- The gust induced a pitch-up and left roll, leading to a loss of airspeed and subsequent aerodynamic stall.
- The pilot lacked the necessary altitude and engine power to recover from the stall once it occurred.