What happened
On 22 August 2002, a BAe.1ob-800B, registration G-RCEJ, was conducting a public transport flight from Farnborough to RAF Northolt. The crew, consisting of a commander and a first officer, intended to perform a Precision Approach Radar (PAR) procedure to assist with controller training. During the approach, radar transmissions indicated that the aircraft drifted above the glidepath approximately one and a half miles from the runway.
As the aircraft transitioned into the flare, the crew reported the activation of the stick shaker at roughly 7 feet above the ground. This was immediately followed by a rapid drop of the left wing. The aircraft subsequently made a heavy touchdown on the left main landing gear, causing a visible bounce observed by air traffic control personnel. The landing resulted in no injuries to the crew, but the aircraft sustained damage to the left wing tip fairing and the left flap.
The investigation
Investigators examined the structural damage and found that the left wing tip and aileron had suffered a light scrape, while the left flap showed signs of abrasion and local buckling. Analysis of the damage indicated that the aircraft had been in a roll attitude of at least 7.6 degrees to the left at the moment of impact. The left main landing gear showed evidence of a severe compression, nearly reaching its maximum travel limit, which supported the conclusion of a hard landing.
Technical inspections of the airspeed indicators and stall warning systems confirmed they were functioning within acceptable tolerances. However, investigators noted that the first officer's airspeed instrument tended to over-read by 1 to 2 knots compared to the commander's instrument. The investigation also focused on the aircraft's speed during the approach, noting that the calculated threshold speed used by the crew was 117 kt, whereas the actual airspeed recorded by the Flight Data Recorder (FDR) was 101 kt.
Findings
- The aircraft stalled just before touchdown due to a combination of factors including the increased normal acceleration during the flare and pressure error corrections.
- The crew had used a calculated threshold speed of 117 kt, which was not cross-checked by the non-handling pilot.
- The aircraft's airspeed at touchdown was approximately 101 kt, which, when adjusted for pressure errors and the 1.15g load factor during the flare, placed the aircraft at its aerodynamic limit.
- The left wing tip and flap made contact with the runway surface due to the significant roll angle during the heavy landing.