JAKARTA (AFP) - 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 Wednesday.
Indonesian Transport Minister Ignasius Jonan said the Airbus A320-200 was ascending at a rate of 6,000 feet (1,800 metres) 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," he told reporters Tuesday.
That ascent is about two to three times the normal climb rate for a commercial jetliner, according to experts.
Indonesian divers recovered the plane's black boxes a week ago, after an arduous search for the jet that crashed on December 28 with 162 people on board. The cockpit voice recorder and the flight data recorder are now being analysed, 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 447 into the Atlantic in 2009, with the loss of 228 lives.
"The similarities are pretty striking," Daniel Tsang, founder of Hong Kong-based consultancy Aspire Aviation, told AFP.
In that case, the Airbus A330 en route from Rio 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.
- 'Phenomenal' climb -
The investigation into AF447 found that both technical and human error were to blame. After the speed sensors froze up 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 - 10,000 feet per minute when at altitude.
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," he 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 thus no indication terrorism played a role.
Indonesia's National Transportation Safety Committee, which is probing the crash, said this week they are now focusing on human or aircraft error as probable causes, after analysing the data from the cockpit recorder.
A huge international hunt for the crashed plane, involving ships from several countries including the US and China, finally located the wreckage at relatively shallow depth in the Java Sea.
Indonesian search and rescue teams have so far recovered just 53 bodies, but hopes that more victims will be found were raised last week when a Singapore navy ship located the jet's main body, with the airline's motto "Now Everyone Can Fly" painted on the side.
However, divers have not succeeded in reaching the fuselage despite several attempts due to bad weather, high waves and strong underwater currents.
All but seven of those on board the flight were Indonesian. The foreign nationals were from South Korea, Singapore, Malaysia, Britain and France.