What happened
On 20 February 2007, a BAe 146-200, registration EI-CZO, operated by CityJet, was performing a scheduled flight from Paris Charles De Gaulle to London City Airport. During the landing roll on Runway 10, the aircraft overran the available landing distance. During the excursion, all four main landing gear tyres burst, and the aircraft eventually came to a stop in a snow drift approximately 3 feet deep at the end of the runway.
While the aircraft remained on the paved surface, the flight crew reported a perceived total failure of the braking system. The aircraft had approached the runway with a landing weight of approximately 33.1 tonnes, and the runway surface was reported as damp.
The investigation
The AAIB investigation examined the flight data, aircraft systems, and crew actions. Investigators found that the approach reference speed (VREF) had been incorrectly calculated as 119 kt, which was higher than the required 114 kt for the aircraft's weight.
Technical analysis of the aircraft revealed that the lift spoilers did not deploy upon touchdown, despite the system being fully serviceable. It was determined that because the lever was not held with positive force, it likely moved away from the activation point before the deployment logic could be satisfied. Furthermore, evidence suggested the control columns may have been positioned forward after touchdown, reducing the weight applied to the main wheels.
When the crew perceived the brakes were ineffective, they transitioned to the emergency braking system. This action removed the anti-skid protection, causing the main wheels to lock immediately, which contributed to the tyre bursts.
Findings
- The approach speed was higher than necessary due to an incorrect calculation of the VREF.
- The non-deployment of the lift spoilers prevented the timely transfer of aircraft weight to the main wheels, reducing braking effectiveness.
- The use of the emergency braking system led to the loss of anti-skid protection and subsequent wheel locking.
- The landing distance available was exceeded due to a combination of higher speed, late touchdown, and reduced braking efficiency.