Weather conditions rarely sole factor in air disasters
A combination of technical, meteorological and human factors usually causes an airplane to crash, says expert.Geneva – Weather conditions might contribute to air crashes but are rarely the only cause of disasters like that of the Air France jet which disappeared over the Atlantic, a UN meteorological expert said Tuesday.
"Weather is probably a factor that contributed to the accident but it is very, very rarely the only cause," said Herbert Puempel, aeronautical meteorology chief at the World Meteorological Organisation.
"Generally, there is a combination of technical, meteorological and human factors," he added.
Some 228 people are missing and feared dead after Air France flight 447 from Rio de Janeiro to Paris went missing over the Atlantic Ocean on Monday, while it was crossing an equatorial zone renowned for turbulent weather conditions.
But officials said what brought down the plane remains a mystery.
Weather conditions are implicated in some way in about two-thirds of air accidents, but "the human factor is also important," explained Puempel, underlining that pilots were under greater stress when they crossed difficult areas.
"For the moment, nothing is ruled out, but we know that in the zone thunderstorms had been observed," said Puempel.
Cloud cover and wind patterns are very complex in the intertropical convergence zone where the Airbus A330 was thought to be flying, which is afflicted with "deep convection thunderstorms," according to the WMO expert.
In some instances, a severe ascending air current with a speed of 100 metres per second (360 kilometres per hour, 223 miles per hour) could be found right next to a descending current of the same speed, subjecting aircraft to severe buffeting, he added.
"On top of that there's the possibility of icing and lightning," said Puempel.
"Normally pilots try to avoid entering such a stormy area... but sometimes it's very wide and it's a real challenge for pilots to find the right course," he added.
Brazilian search aircraft found debris on Tuesday that they said were from the Air France flight 1,100 kilometres (680 miles) off Brazil's northeast coast.
AFP / Expatica