US investigators have indicated that a Saab 2000 touched down in a tailwind during a second attempt to land at an Alaskan airport, before it suffered a fatal excursion.
US investigators have indicated that a Saab 2000 touched down in a tailwind during a second attempt to land at an Alaskan airport, before it suffered a fatal excursion.
The PenAir turboprop, arriving at Unalaska on 17 October, approached runway 13 with the wind from 300° at 24kt – suggesting a tailwind component of more than 23kt.
While its airspeed was 129kt at touchdown the aircraft’s groundspeed was 142kt, according to the flight-data recorder.
According to the US National Transportation Safety Board, the crew told the inquiry that the aircraft landed about 1,000ft down the 4,500ft runway. Reverse thrust and braking commenced and the captain applied maximum braking around the ‘80kt’ call-out.
But the aircraft did not stop before the runway end and the crew attempted to steer to the right to avoid entering the water beyond.
As the aircraft overran – about 26s after touchdown – its left-hand propeller struck a road sign, and possibly a signal post, losing three of its six blades. At least two blades hit the fuselage, one sticking in the structure and the other entering the passenger cabin. The third missing blade was retrieved from the water.
The fuselage had been holed on its left side around the fifth passenger window, which is located slightly ahead of the rotation plane of the propeller. All the cabin seats, comprising 15 rows, were intact with the exception of window seat 4A, which was displaced and damaged.
All three of the other left-hand propeller blades were broken.
One passenger was fatally injured, says the inquiry, but its preliminary findings do not elaborate on the nature of the injuries. The aircraft, which had been operating from Anchorage, was transporting 42 occupants.
The turboprop had been cleared for an area navigation approach to runway 13 with winds gusting from the south-west.
These winds shifted towards a westerly direction, at 10kt, during the approach. The crew felt the approach was unstable and executed a go-around.
“Transmissions between the weather observer and another [aircraft] indicated that winds favoured [the opposite] runway 31 but could shift back to runway 13,” says the inquiry. The Saab crew re-established the aircraft on the runway 13 approach.
Investigators state that an examination of the runway found a dark rubber mark 15ft left of the runway centreline, some 1,840ft from the threshold and extending for 200ft. The aircraft’s left-hand outboard tyre was found to have completely worn through and deflated.
While the Saab’s captain had accumulated around 20,000h including 14,000h in Bombardier Dash 8s, only 101h had been logged on Saab 2000s. The first officer had 147h on the type, out of a total of 1,446h.
