Thu, Jan 22, 2015 - Page 6 News List

AirAsia jet climbed, then stalled

UNUSUAL ASCENT:An analyst said the rate of climb of the jet was ‘just phenomenal,’ and that it would be very unusual for the weather alone to cause such a rapid ascent


Revelations that AirAsia Flight QZ8501 climbed too fast before stalling and plunging into the sea point to “striking” similarities between the Java Sea accident and the 2009 crash of an Air France jet, analysts said yesterday.

Indonesian Transport Minister Ignasius Jonan said the Airbus A320-200 was ascending at a rate of 1,800m a minute before stalling, as it flew in stormy weather last month from Indonesia’s Surabaya to Singapore.

“In the final minutes, the plane climbed at a speed which was beyond normal,” Jonan told reporters on Tuesday.

That ascent is about two to three times the normal climb rate for a commercial jet, according to experts.

Indonesian divers recovered the plane’s black boxes a week ago, after an arduous search for the jet that crashed on Dec. 28 last year with 162 people on board. The cockpit voice recorder and the flight data recorder are now being analyzed, with a preliminary report due next week.

While they stressed the difficulty of drawing conclusions without seeing the full black box data, analysts said the accident had strong echoes of the crash of Air France Flight AF447 into the Atlantic in 2009, with the loss of 228 lives.

“The similarities are pretty striking,” said Daniel Tsang, founder of Hong Kong-based consultancy Aspire Aviation.

In that case, the Airbus A330 en route from Rio de Janeiro to Paris vanished at night during a storm.

The aircraft’s speed sensors were found to have malfunctioned and the plane climbed too steeply, causing it to stall. As with the AirAsia disaster, the accident happened in what is known as the “intertropical convergence zone,” an area around the equator where the north and south trade winds meet, and thunderstorms are common.

The investigation into AF447 found that both technical and human error were to blame. After the speed sensors froze and failed, the pilots failed to react properly, according to the French aviation authority, who said they lacked proper training.

Jonan on Tuesday likened the doomed plane’s ascent to a fighter jet, although experts noted that warplanes can climb considerably faster.

However, Tom Ballantyne, Sydney-based chief correspondent for Orient Aviation magazine, said the rate of climb of the AirAsia jet was “just phenomenal,” adding: “I’m not sure I’ve heard of anything that dramatic before.”

He said it would be unusual for weather alone to cause such a rapid ascent, but added it was possible if the jet hit “some bizarre unprecedented storm cell.”

“It is possible that the aircraft could have got caught in some sort of updraft that lifted it thousands of feet,” he said.

However, while saying the rapid ascent showed that there was “something very wrong,” Gerry Soejatman, a Jakarta-based independent aviation analyst, added it was too early to have a firm read on the cause of the crash.

“Although there are similarities with Air France, and the weather seems to be a factor, we can’t make any conclusions that this is caused by the weather or icing — it’s too early,” Soejatman said.

Nevertheless, Tsang said the probe was unfolding as analysts had predicted, with no explosions or loud bangs registered on the cockpit voice recorder, and therefore no indication terrorism played a role.

The Indonesian National Transportation Safety Committee, which is probing the crash, this week said they are now focusing on human or aircraft error as probable causes, after analyzing the data from the cockpit recorder.

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