Investigators probing ATR 72 loss warn airlines to review instructions given to crews

A safety recommendation from Taiwan's Aviation Safety Council (ASC) following the 21 December TransAsia Airways ATR 72 freighter crash urges all airlines operating turboprop aircraft to "review their training programmes" to ensure that they include comprehensive instructions on flying in icing conditions.

The Taiwan-based ATR 72 freighter was cruising at FL180 (18,000ft/5,500m) en route from Taipei to Macau when the pilots called for descent to FL160. Shortly after they were cleared to descend, the aircraft went out of control and plunged into the sea. Ground temperature at the departure airport was 20°C (68°F), and at cruising level it was –9°C with some cloud, according to the ASC. The ASC's recommendation says: "All operators with turboprop aircraft [should] review their training programmes to ensure the programme contains the necessary training for pilots to recognise and effectively respond to all levels of icing conditions." It also advised that the training should improve pilots' "situational awareness of icing conditions".

K F Chou, the ASC's senior investigator for the accident, says: "This bulletin is for all turboprop aircraft, not only ATRs." He confirms the organisation's main concern is the time between the crew acknowledging icing and finally acting to clear it when it became severe.

France's Bureau Enquete Accidents (BEA) says in a parallel recommendation: "It appears that the crew identified an icing situation and that, around 20min later, they lost control of the aircraft." Cockpit voice recorder (CVR) information suggests the pilots had first mentioned icing nearly 20min before activating the de-icing system, which they did just before the aircraft went out of control (Flight International, 28 January-3 February). The ASC says: "The CVR stopped recording 73s after the severe icing conditions were recognised by the crew."

Source: Flight International