What happened
On 27 May 1999, a Cessna 172M, registration G-TRIO, was conducting a private training flight at Biggin Hill, Kent. During the approach for runway 11, the pilot intended to select the 20-degree flap setting but instead activated the 40-degree position. While the pilot noted being too high on the approach, they chose to continue the landing rather than performing a go-around.
Upon touchdown, the aircraft bounced multiple times, prompting the pilot to initiate a go-around by applying full power. During the subsequent climb, the aircraft exhibited sluggish performance. The pilot then identified that the flaps were set to 40 degrees instead of the intended 20 degrees. At an altitude of approximately 30 feet, the pilot retracted the flaps to the 20-degree position and lowered the nose to mitigate a brief stall warning. The aircraft subsequently completed a normal circuit to land safely.
The investigation
The investigation examined the aircraft's electrical flap operating system, which uses a switch to move the flaps to a desired position before being returned to a neutral power-off state. The investigation also reviewed the pilot's flight experience and the environmental conditions at the time, which included a 11-knot wind and clear visibility.
Findings
- The pilot inadvertently selected the 40-degree flap setting during the base leg of the approach.
- The pilot failed to execute an immediate go-around when they realized the aircraft was too high on the approach.
- The aircraft experienced a brief stall warning during the climb-out due to the high drag from the incorrect flap setting.
- There were no injuries to the pilot or the two passengers, though the aircraft sustained substantial structural damage.