What happened
On 5 February 2008, a Cessna 550 Citation Bravo, registration G-IKOS, was conducting a private night approach to Biggin Hill Airport. While flying a fully coupled approach to Runway 21, the aircraft encountered severe windshear at approximately two miles from the runway threshold. The encounter caused the airspeed to drop significantly, prompting the autopilot to pitch the aircraft up to maintain the glideslope, which resulted in a right-wing drop and a near-stall condition.
The commander responded by lowering the nose and increasing power to recover. Although the crew noted the windshear, the approach was continued at a speed near the minimum limit. The initial touchdown was flat, leading to a series of porpoising bounces. During the second bounce, the first officer requested a go-around, but the commander elected to continue the landing. The aircraft eventually came to a stop within the runway limits without further incident.
The investigation
The investigation involved an analysis of the aircraft's Flight Data Recorder (FDR) and Cockpit Voice Recorder (CVR). The FDR confirmed that the aircraft experienced a significant loss of airspeed during the windshear event and recorded high vertical accelerations during the subsequent bounces. The CVR captured the crew's discussion regarding the windshear and the decision to continue the approach despite the unstable airspeed.
Findings
- The aircraft encountered a rapid change in wind velocity of approximately 40 knots during the final 1,500 feet of the approach.
- The pilot flying maintained a speed close to the minimum approach limit, which reduced the safety margin during the windshear encounter.
- The decision to continue the approach despite the unstable airspeed and the windshear event contributed to the bounced landing.
Safety action
Following the incident, the operator implemented new stabilized approach criteria. These rules mandate a go-around if the aircraft is not stable by 500 feet above ground level or if the approach becomes destabilized below that altitude.