F27 Overran in Crosswind
PUBLISHED: 12:44 23 June 2011 | UPDATED: 14:06 10 October 2012
A Fokker F27 touched down deep and ran off the runway at Guernsey, after the effects of a strong crosswind had compromised braking.
A Fokker F27 touched down deep and ran off the runway at Guernsey, after the effects of a strong crosswind had compromised braking. The aircraft struck an earth bank and ended up outside the airport's perimeter.
The first officer suffered a minor back injury on impact and one of the passengers received a head injury during the evacuation. The aircraft was damaged beyond economic repair. The accident was not however, the result of simple misjudgement or mishandling on the crew's part.
The first officer had been the handling pilot for the take off from Southampton. He reported that the aircraft 'was difficult to keep straight' on the runway. The captain and first officer were both aware that the wind at their destination was likely to be close to the aircraft's crosswind limit (29 knots, according to the company operations manual).
Prior to landing the first officer had obtained the latest weather for Guernsey from the recorded ATIS. This gave the surface wind as 170 degrees/19 knots, with gusts to 32 knots. In his approach briefing, the captain told the first officer he would make an ILS approach to Runway 27 using 26.5 rather than forty degrees of flap, and aim for an extra ten knots on the threshold speed.
The first approach was missed because the captain judged the aircraft to be too high. On the second, more stable, approach a drift angle of between thirty and forty degrees was noted. ATC cleared the aircraft to land and reported the surface wind to be 180 degrees/18 knots. Approximately twenty seconds before touchdown the crew were told the wind was 190 degrees/twenty knots.
As prescribed in AIC 4/1997, published earlier in the year the accident took place, the wind figures reported were two minute averages, taken from an anemometer close to the designated touchdown point. At the time of the accident, the surface wind was actually gusting to 34 knots. Although the F.27's crew did not ask for the 'instantaneous wind', the controllers had discretion to offer this information as stated in the CAA's Manual of Air Traffic Services; they did not use it.
The aircraft touched down at least 1,800 feet into the 4,797 foot runway. Once it was on the ground, braking effort was compromised by the need to keep the aircraft running straight; the captain had to hold on full right rudder and brake, and was 'standing up in his seat' with the effort, according to the first officer. The aircraft reached the end of the runway at a speed of thirty knots, turning left and skidding to the right.
It was fortunate that were only the two injuries: at the time the airport had no functional disaster plan and passengers were kept waiting outside in the cold for fifteen to twenty minutes. Several suffered from the effects of the cold.