SINGAPORE – The disappearance of an AirAsia jetliner while flying over the Java Sea on Sunday is probably due to stormy weather, but there were also some unusual factors, aviation experts speculated Monday.
Based on information known so far, the pilots of AirAsia Flight QZ8501, which was about an hour into the flight from Surabaya to Singapore, informed ground traffic controllers they wanted to take the plane up to 38,000 feet from 32,000 amid bad weather. Aviation analysts said pilots would usually try to fly around a thunderstorm or turbulence rather than through it.
It is also unusual there has been no sign of the plane or debris from the wreckage after more than 24 hours had passed as the Java Sea at the location has quite brisk sea traffic.
Keith Mackey, a U.S. aviation expert, who heads Mackey International, an aviation consultancy, said the incident was probably due to weather as there was a lot of bad weather and thunderstorms in the area.
He said thunderstorms can cause severe to extreme turbulence, but normally pilots would fly around thunderstorms rather than through them.
However, he found it quite unusual that the one of the pilots said he was going to bring the plane to 38,000 feet from 32,000.
“Pilots might change (altitude) due to turbulence, but would usually make smaller incremental changes. I find that unusual to make that large altitude change. The option is to avoid flying though the turbulence. Normally using a weather radar you can see a couple of hundred kilometers ahead,” he said.
Mackey added he believes searchers should be able to find the wreckage of the plane as the Java Sea is not such a large area, is shallower than the Indian Ocean and there is a lot more sea traffic plying the area.
“The search should be much smaller than MH370,” he said, referring to the Malaysia Airlines plane that has been missing since March.
MH370 is believed to have gone down in the Indian Ocean, but no sign of the plane has been found since it disappeared from radar nine months ago.
As to no distress signal sent from the AirAsia plane, Mackey said, if there was major trouble on board the pilot would be busy solving the problem rather than making calls.
Aviation expert Mark Martin of Martin Consulting also speculated “the aircraft may have encountered bad weather” and he too suggested pilots would usually try to fly around rather than over poor weather.
With 155 passengers on board, “clearly it appears that the aircraft was heavy and the fuel uplifted was not entirely burnt to ease a climb action,” he added, noting if a plane enters a storm cloud at levels between 31,000 to 38,000 feet, it is common to see heavy updrafts and downdrafts, icing on control surfaces that can freeze corrective pilot actions and the aircraft could plunge more than 5,000 feet a minute.
In that case, pilots would normally take the standard recovery step of regaining control of the aircraft first, and only convey a distress message later.
Shukor Yusof, aviation analyst at Endau Analytics in Malaysia, said he does not expect the incident to have a big impact on AirAsia’s business.
“I would say this is just a blip for them,” he said. “AirAsia share prices (were) badly hurt (Monday), that’s understandable. In the short term people will react, but in the longer term this is a very strong company with a very sound business model and solid management,” he said.
“It’s the first airline that started a budget airline in Asia, the biggest low-cost carrier in Asia and it has the first-mover advantage, it has very strong foundation, the banks and shareholders are very much behind the carrier, they have very good market share not only in Malaysia but also in other parts of the world, such as India and Japan,” he said, adding even Indonesia has been improving its aviation safety standards in the last five years.