What happened
On March 10, 2018, at approximately 06:30 UTC, a Boeing 757-208, registration TF-FIV, was taxiing at Keflavík Airport following a passenger flight from Seattle. Due to heavy snowfall, several aircraft were in a holding pattern awaiting runway clearance. As the aircraft approached the intersection of runway 19 and taxiway S2, the crew was instructed to vacate the runway via a right turn onto S2.
At the time of the incident, visibility was significantly reduced by snow, and the taxiway lighting was inadequate due to ongoing airport construction. The crew found it difficult to identify the exact location of taxiway S2, eventually following the path of a preceding aircraft. Upon entering the taxiway, the pilot noted the aircraft began to slide toward the left edge of the pavement. In an attempt to correct the drift, the pilot applied power to the left engine but then mistakenly applied full reverse thrust to the right engine. This maneuver caused the aircraft to pivot sharply, resulting in the nose gear leaving the paved surface of taxiway S2. There were no injuries and no damage to the aircraft.
The investigation
The RNSA investigation examined the weather conditions, airport maintenance procedures, and the sequence of taxiing instructions. The investigation established that heavy snowfall had accumulated on the taxiways, with snow depths on S2 measured at approximately 34 cm. While runway 19 had been prioritized for clearing, taxiway S2 had not yet been treated.
Investigators also reviewed the airport's lighting infrastructure, finding that several taxiway lights were not yet operational due to construction, and the S2 directional signage was obscured by snow. Furthermore, the investigation looked into the timing of the aircraft's arrival, noting that the aircraft landed only about 40 seconds after the preceding aircraft had reported clearing the runway, creating pressure to vacate the runway quickly.
Findings
- The primary cause of the excursion was the pilot's application of full reverse thrust on the right engine, which induced a sharp turn.
- Poor visibility caused by ongoing snowfall and inadequate taxiway lighting made it difficult for the crew to identify the taxiway intersection.
- The taxiway surface was contaminated with significant snow accumulation.
- The lack of updated NOTAMs regarding the degraded lighting conditions contributed to the crew's difficulty in navigating.
- High-density arrival sequences created operational pressure to vacate the runway quickly before the next arrival.