Transcript indicates ice build-up was factor in TransAsia accident
The cockpit voice recorder (CVR) transcript from the TransAsia Airways ATR 72-200 that crashed on 21 December reveals the pilots discussed ice build-up on the aircraft 20min before it went out of control and dived into the sea.
The freighter, bound for Macau from Taipei, crashed into the Taiwan Strait 47min after take-off, 30km (16nm) south-west of Penghu Island.
Taiwan Aviation Safety Council investigator Tracy Jen says CVR and flight data recorder readings show the aircraft was cruising at FL180 (18,000ft/5,500m) at 01:32:34 when the co-pilot told the captain about ice build-up. About 1min later the captain also referred to icing.
At 01:34:40, the crew manually selected the aircraft's wing de-icing system, says Jen. The autopilot was engaged at the time and the outside air temperature (OAT) was –2°C. The de-icing system shut off automatically at 01:37:31 after the OAT increased to 0°C. The crew activated the system again at 01:41:32 when the temperature fell to –1°C. At 01:51:50 the crew requested descent to FL160 and clearance was granted. Jen says that 20s later, when the aircraft was passing 17,853ft, stall warning and stick shaker sounds were recorded. After 2s, the autopilot disengaged and the aircraft banked sharply left and right. Over the next 35s the aircraft plunged towards the sea.
Source: Flight International
