Aviation Accident Report
Preliminary report
Date of Incident: 28th July 2002
Location: Rarotonga International Airport, Cook Islands, South Pacific
Aircraft: Boeing 767-300 Extended Range, EI-5CA
Details:
The aircraft was in the cruise at FL350 under FMS control on a charter flight from New Caledonia to Tahiti. About 900nm from the destination airport the aircraft suddenly pitched up in excess of 25 degrees and in this configuration its speed rapidly reduced. The autopilot endeavoured to maintain the altitude but a steady descent commenced and the airspeed dropped alarmingly to just above stall speed. The crew disconnected the Autopilot and FMS and endeavoured to regain control of the aircraft. In order to restore the airspeed they had to maintain forward pressure on the control yoke. By this time the altitude was 29000ft with the engine rpm's at maximum. Efforts were made to climb the aircraft back to FL350 and this was finally achieved manually. However, on reactivating the autopilot the whole sequence began again.
At this point the crew decided to declare an emergency and divert to Rarotonga International Airport in the Cook Islands which was a distance of some 280nm. Although having to continually "fight" the elevator trim the descent and approach to the field was successful, the weather being calm with few clouds. Runway 8 at Raratonga is only 7600ft and, in view of all the circumstances, it was considered necessary to land as close to the threshhold as possible to ensure the maximum possible stopping distance was available.
The aircraft touched down close to the centreline but, as the nose lowered and just after reverse thrust was engaged it tilted violently to the right and began to veer off the runway at which point the nosewheel collapsed. Smoke appeared at the mid-section of the fuselage just aft of the wings and, as the aircraft came to a full stop on the grass, its nose buried in the ground, a fire broke out. The emergency services were quickly on the scene but the centre section of the aircraft was destroyed.
Investigation Report:
The incident at cruise level is the subject of ongoing investigation so this report will concentrate on the landing and subsequent crash.
It is evident that the approach and landing was normal but that shortly after touchdown, the right main gear collapsed causing the No. 2 engine to impact the runway surface and veer the aircraft to the right. As it exited the runway the nosewheel also collapsed.
The main focus of the enquiry was on the aircraft design. In FS2002 there is a bug which, at certain locations, causes "invisible holes" to appear in runways and/or taxiways. In the case of most aircraft the only effect is that a bumpy ride is experienced when these holes are encountered. However, with a small number of aircraft, including this particular design, the effect is more dramatic - the landing gear collapses.
Subsequent tests at airports where the holes exist, including Rarotonga, showed that this B767 model is incapable of negotiating these areas and on all occasions the gear just collapsed. Inquiries on various Forums have confirmed this.
Consequently, the ultimate cause of this accident was the failure of the landing gear after a normal touchdown due to a combination of the FS2002 bug and an aircraft design which failed to address this bug.
Due to the somewhat unhelpful and frosty attitude of the designers to the problem it is recommended that the airline look elsewhere for a replacement of the type.