Storm ice suspected in Etihad A340 cruise incident
From Flightglobal, 10:47 2 Apr 2013:
Storm ice suspected in Etihad A340 cruise incident
Pilots of an
Etihad Airways Airbus A340-600 diverted to Singapore after a sudden encounter with turbulent weather during cruise generated unreliable airspeed data and left the jet unable to maintain altitude separation requirements.
While en route to
Melbourne at 35,000ft, and approaching the PIPOV waypoint over the Indian Ocean, the returns from the aircraft's weather radar - which had no auto-tilt function - suddenly intensified to indicate surrounding convective weather.
Airspeed on the captain's primary flight display rapidly dropped from 283kt to 77kt before fluctuating, and the standby instrument recorded a fall from 280kt to 142kt. The first officer's reading stayed stable.