What happened
On 9 August 2012, a Falcon 20E, registration G-FRAI, was performing a commercial passenger flight at Durham Tees Valley Airport. During the takeoff roll on Runway 23, the commander observed a large bird near the runway centerline approximately 250 meters ahead. Fearing a potential birdstrike that could damage the engines or control surfaces, the commander decided to abort the takeoff.
The crew initiated the rejected takeoff by retarding the thrust levers and applying maximum braking and airbrake deployment. However, the aircraft was traveling at approximately nine knots above the calculated V1 speed when the decision to stop was made. As the aircraft approached the end of the runway, the crew realized the deceleration rate was insufficient to stop within the remaining distance. The aircraft exited the runway, crossed the stopway, and entered the grass Runway End Safety Area (RESA). The soft ground of the RESA eventually brought the aircraft to a halt, though the landing gear sank into the earth and the engines ingested mud and stones.
The investigation
The AAIB investigation was significantly constrained by the absence of a Cockpit Voice Recorder (CVR) and Flight Data Recorder (FDR), as the aircraft operated under a UK CAA exemption. Investigators relied on data from the aircraft's electronic warfare training system (SADS), though the sampling rate was noted as being insufficient for high-fidelity analysis of the exact sequence of events.
Technical examinations of the braking system showed that the anti-skid and hydraulic systems were fully operational. A seized right inboard brake was traced to small amounts of friction lining material melting and fusing the components during the high-energy braking event. Analysis of the runway surfaces revealed that while the main runway friction was adequate, the friction characteristics of the stopway were substantially lower, likely due to loose gravel and different surface material, which contributed to the reduced deceleration.
Findings
- The takeoff was rejected at a speed approximately 9 knots above the calculated V1.
- The reduced friction of the runway stopway significantly hindered the aircraft's ability to decelerate during the final stages of the rejected takeoff.
- The decision to abort was prompted by the sighting of a bird, which the commander believed posed an imminent threat.
- The aircraft experienced engine damage due to the ingestion of mud and stones during the overrun.
- The lack of onboard flight recorders prevented a definitive determination of the exact timing of the crew's actions.