AirAsia pilot’s request to fly higher risky, unusual –PHL aviation expert

Though it was not clear what happened to the Singapore-bound AirAsia plane that went missing Sunday morning, the request of the plane's pilot to fly at higher altitude was quite unusual and very risky, an aviation expert said Monday.

In a phone patch interview with GMA News TV's “News To Go,” Capt. John Andrews said it was quite unusual that the pilot of the missing Indonesia AirAsia Flight QZ8501 asked permission to fly from 32,000 feet to 38,000 feet reportedly to avoid “storm cloud” or thunderstorm when he could have avoided it by flying sideways.

“Base sa mga report na natanggap natin, nakakapagtaka na nanghingi daw ng unusual deviation. Normally kung meron kang nakitang thunderstorm or malaking ulap na merong kasamang lightning, iiwas ka either kaliwa o kanan,” said Andrews, a former deputy director general of the Civil Aviation Authority of the Philippines (CAAP).

“Kasi itong mga eroplanong ito, A300, meron namang sophisticated radar ito, makikita mo lahat ng mga turbulent area at pwede mong iwasan,” he added.

According to a Reuters report, the plane lost contact with air traffic control in Surabaya in Indonesia at 6:17 a.m. on Sunday, five minutes after its pilot asked permission to fly at higher elevation. The permission has not been given to the pilot when the communication was abruptly lost.

The plane, an Airbus A320, was carrying 162 people, including the pilot and crew, the report said.

Very risky move

Andrews explained that though it was not clear if the pilot indeed flew over the thunderstorm or to 38,000 feet or higher, such move was very risky for any commercial planes.

“Alam niyo po sa katagalan ko na lumilipad, ako po ay never nag-attempt na tumaas pa sa thunderstorm buildup. Delikadong-delikado po iyan kasi ang eroplano, may tinatawag yan na service ceiling. Ang service ceiling ng A300 maximum is about 38,900 feet. Itong mga thunderstorm na ito, umaabot ito ng lagpas 40,000 feet. Hindi mo talaga pwede liparan ito sa taas,” he said.

Andrews pointed out that if a plane has reached or exceeded it service ceiling, it has a tendency to stall in the air and fall “like a rock” with just a slight disturbance.

“Kapag mataas na mataas na yung eroplano, kapag nasa service ceiling na siya, malapit na po yun sa stalling stage... Kasi habang tumataas tayo, yung hangin ay numinipis, so mawawalan ng lift yun. Maski lang po magkaroon ng konting turbulence, kapag mataas na mataas ka ay mag-iistall po yung eroplano... kung nag-stall yun babagsak po yun na halos parang bato. Wala na po kayong control dun,” he said.

He added that this might have caused the abrupt loss of the plane's communication system, though clarified that it was just his personal theory.

“Kung nag-breakdown ang eroplano, lahat ng kanilang tinatawag na transponder, mawawala na lahat kaya wala nang makikita sa radar.... kung nagkaroon sila ng disastrous explosion or disintegration of the aircraft because of the turbulence, lahat ng system nila mamamatay na po,” Andrews said.

Storm clouds

Andrews pointed out that it was quite impossible that the pilot was not able to see the storm cloud from several miles away given the “sophisticated” weather radar that A320 planes usually have.

“Yung radar nakakakuha yan ng range mga 200 miles away, 20 mins away makikita mo na na merong buildup dun, pwede mo na ilagan yun malayo pa. Yung mga thunderstorm ang laki niyan mga 10 to 20 miles ang width kaya ang dali-dali iwasan niyan,” Andrews said.

He added that pilots flying in Southeast Asia are used to thunderstorms and the common practice is to avoid them by flying sideway.

“Walang kaso yung thunderstorm, dito lang sa Pilipinas, daan-daan ang mga thunderstorm natin, pero iniiwasan po yan ng mga piloto either pakanan o pakaliwa...Wala pa ako narinig na nag-iwas diyan pataas kundi ngayon lang po. Kaya tinatanong ko po kung gano ka-experienced ang piloto nila at sinubukan po ang ganun,” Andrews said.

Human error?

He, however, said that it is hard to categorically say that the incident can be attributed to human error, as the pilot and his crew might have experienced technical problem.

“Pwede din po na nagkaroon ng problema sa weather radar nila at hindi nila magamit, kaya inisip nila, pataas na lang,” he said.

“Hindi pa natin malaman kung nagkamali siya [pilot] o nagkaroon siya ng equipment failure na hindi na niya nakikita kung ano ang nasa harapan niya. Kapag na-retrieve na ang blackbox, mga flight data recorder, diyan makikita kung ano talaga ang nangyari,” he added.

Two Indonesian C-130 planes and two navy vessels are now conducting search operations over Java Sea between Surabaya and Singapore, while more vessels from Singapore are on the way to help in the operations.

The United States, Britain, South Korea and India also offered help, according to Reuters report. —Elizabeth Marcelo/KBK, GMA News