Incident Overview
On 28 October 2019 at 06:04 local time, a BAE 125 series 800A aircraft, registration N812AM, operating a medical evacuation flight with eight persons on board, suffered a runway excursion at Keflavik Airport (BIKF). The aircraft touched down on runway 01 at 06:03 and was instructed by air traffic control to clear the runway at the end using taxiway N. After slowing to taxi speed, the pilot flying reported encountering black ice at the junction of runway 01 and taxiway N, and was unable to slow sufficiently to make the turn. The aircraft skidded off the far end of the runway, entering the paved safety area before stopping. No injuries occurred among the occupants, and the aircraft sustained no damage.
Weather and Runway Conditions
During the night preceding the incident, the airport operator, Isavia, faced difficulties maintaining good braking action. Rain fell between 03:30 and 04:30, freezing on contact with the frozen ground. Runway deicing fluid was applied three times before braking action became acceptable. The last braking measurement before the landing, taken at 05:55 on runway 19-01, showed an average coefficient of 0.46, but the measurement at the runway 19 threshold (the far end of runway 01) was 0.22, classified as poor braking action per ICAO Annex 14. Taxiways and aprons required repeated sanding throughout the night due to drizzle.
Incident Sequence
The aircraft landed normally and began taxiing toward taxiway N. According to a witness, the aircraft did not appear to reduce speed as it approached the end of the runway. Once the aircraft entered the threshold markings for runway 19, braking was applied, but the aircraft skidded off the runway into the safety area. After exiting the aircraft, a crew member slipped on the icy paved safety zone but was not injured.
Investigation Findings
The Icelandic Transportation Safety Board (ITSB) investigated the serious incident. The investigation determined that the runway excursion was caused by poor runway condition at the far end of the runway, specifically the area near the threshold of runway 19, where the braking action coefficient was measured at 0.22. The on-site evidence was disturbed before the ITSB could examine it, as Isavia moved the aircraft without prior notification to the board.
Safety Recommendations
The ITSB issued one safety recommendation to Isavia: during braking action measurement, if abnormally worse braking actions are measured at the runway ends that do not concur with the average one-third runway value being measured, pilots should be notified.
Probable Cause
The ITSB stated that the cause of the runway excursion was poor runway condition at the far end of the runway.