What happened
On 6 September 1999, an aircraft with registration LN-PBB was performing a scheduled mail delivery service from Aberdeen to the Shetland Islands. After an initial flight from Denmark to Aberdeen the previous day, the crew prepared the aircraft for its morning duty. The flight crew and ground personnel loaded 1,196 kg of mail, which had been weighed and verified by the operator. Although the weather at the destination, Sumburgh Airport, was initially reported as poor, the crew proceeded with the flight. After an intermediate diversion to Kirkwall due to weather conditions at Sumburgh, the crew departed Kirkwall at 0950 hrs to attempt the landing.
During the approach to Runway 27 at Sumburgh, the aircraft was utilizing the ILS. The crew encountered low cloud ceilings and a wet runway. As the aircraft descended, the pilot flying experienced difficulty maintaining the localizer and glide slope. The aircraft approached the threshold with excessive speed, which the co-pilot noted. Upon crossing the threshold, the aircraft bounced and made a second touchdown approximately halfway down the runway. Despite the application of full braking, the aircraft failed to decelerate sufficiently. To avoid hitting concrete sea defenses at the end of the runway, the commander applied full power, causing the aircraft to yaw left. The Twin Otter exited the runway, crossed a public road and a grass area, and eventually came to a stop against the concrete blocks. There were 0 fatalities and 0 injuries reported in this incident.
Findings
- The aircraft approached the runway with excessive airspeed.
- The crew failed to effectively manage the aircraft's deceleration following a bounced touchdown.
- The pilot applied full power during the landing roll in an attempt to avoid runway end obstructions.