By Charles Bremner | Times Online
The crew of an Ethiopian airliner that crashed off Lebanon on Monday apparently flew into violent storms after failing to follow controllers’ instructions to avoid them, it emerged today.
“A traffic control recording shows that the tower told the pilot to turn to avoid the storm, but the plane went in the opposite direction,” Elias Murr, the Lebanese Defence Minister, said. “We do not know what happened or whether it was beyond the pilot’s control.”
All 90 on board the Ethiopian Airlines Boeing 737 died when the aircraft hit the Mediterranean shortly after taking off from Beirut airport at 2am. Initial reports talked of a possible mid-air explosion and a possible engine fire before the aircraft took off, but the nearby thunderstorms were seen as a more likely explanation.
Violent cumulonimbus, or thunder, clouds can lead to the destruction of even the biggest aircraft. Airliners fly around them, guided by their own weather radar and sometimes by ground controllers as well.
When flight ET409 took off, controllers gave it vectors — compass headings — to steer around a line of powerful storms that crossed its path over the Mediterranean. Such instructions from departure control are common in the first minutes of flight when bad weather is near by.
Flight ET409 disappeared from radar after five minutes of flight after apparently flying straight into the line of storms.
Ghazi Aridi, the Lebanese Transport Minister, said that the pilot at the controls flew in the opposite direction to that advised by the controllers. They “asked him to correct his path but he did a very fast and strange turn before disappearing completely from the radar,” he said.
There was no indication over what caused the crew to follow the wrong heading.
Severe weather has been blamed for many airliners disasters, most recently the crash of a Kenyan Airways Boeing 737 in Cameroon in 2007.
A line of violent thunderstorms is also believed to have been a major factor in the crash of Air France flight 447 that came down off Brazil last June 1. The causes have not yet been determined, but the sequence that led to the crash began when the Airbus A330 flew into violent storm cells, then, in heavy turbulence and rain, its speed-reading probes were blocked by water or ice.
The explosive vertical columns of wind in the heart of mature cumulonimbus clouds can quickly send aircraft out of control and even rip off their wings and tails. There is speculation among airline pilots today that the pilots of the Ethiopian Boeing may have lost control in such violent weather.
Without correct recovery by the pilots, this could have led to a stall or spin and a crash, or even a mid-air break-up. The aircraft was only at about 8,000ft altitude as it climbed away from Beirut. This would have given the crew very little time to regain control.