A FAULTY AIR-SPEED indicator has emerged as a possible factor in the 6 February crash of a Boeing 757-200 in the Caribbean, which claimed 189 lives.
Dominican Republic accident investigators, aided by the US National Transportation Safety Board, say that data from the recently retrieved cockpit-voice recorder (CVR) and flight data recorder (FDR) revealed problems with the captain's air-speed indicator. The crew of the Birgenair aircraft, which was bound for Germany, on a charter flight "...were talking about discrepancies in air-speed readings," says Boeing.
The Dominican authorities reveal that the FDR showed 335kt (620km/h) indicated airspeed (IAS) when the stall-warning stick-shaker activated at 7,300ft (2,200m), but stalling speed is somewhere near 130kt IAS, depending on the aircraft's weight and configuration. The stick shaker operated for 83s before the aircraft crashed, indicating that the pilots failed to recover the aircraft from the stall.
Boeing says: "At this point, there is an indication of discrepancies in air speeds." A company source adds: "We are looking at those things, that could cause that scenario to occur." These include malfunction of the pilot tubes, of which the 757 has three. The CVR indicates that the co-pilot was calling the speeds during the take-off run, implying that he was the non-flying pilot on that flight.
A 28-year-old Boeing 737-200 (OB-1451) of Peruvian carrier Faucett Airlines crashed on a 29 February Lima-Arequipa domestic flight, killing all 117 passengers and six crew on board. The aircraft crashed at 8,200ft in mountains on the approach some 8km (4.3nm) from Arequipa, the airline says. The accident took place at 20:15 local time in rain and mist, with thunderstorms reported in the area, but the airport was accepting other flights at the time and operating normally. See Air Transport, P11.
Source: Flight International