THE OFFICIAL UK report on 1994's fatal crash of a Vickers Viscount freighter, following multiple engine ice-ingestion, severely criticises the crew's actions and the airline's emergency checklist.
Two of the 36-year-old aircraft's four Rolls-Royce Dart turboprops flamed out after ingesting ice at 18,000ft (5,500m). The crew of the British World Airlines aircraft, re-started one engine but lost another and they eventually crashed near Uttoxeter, with both starboard propellers wind-milling un-feathered. The captain died and the first officer was severely injured.
The accident chain began, when the crew, with a serviceable weather radar switched off, flew into an area of forecast "very severe" icing conditions.
The report says that the aircraft was in icing conditions beyond the design capability of its anti-icing systems for at least 11min. Then, after two of the aircraft's engines failed, its reduced icing-protection made the situation worse.
The Air Accidents Investigation Branch's report says that the operator's emergency checklist was never consulted, and the crew's resulting incomplete actions reduced its chances of recovery. The crew had not undergone crew-resource management training.
Concerned about the airline's emergency checklist, the AAIB consulted an aviation psychologist who commented that it "...infringes most of the basic human factors considerations in the design and presentation of visual information".
The crew did not declare an emergency, even with double engine-loss and having requested an immediate descent, rejected east Midlands Airport in favour of more distant Birmingham as an emergency diversion.
The crew finally lost control of the aircraft in yaw when only the left engines remained operating and no ice protection was operating on the right wing. The flight had begun with the No 1 electrical generator unserviceable.
Source: Flight International
