PETALING JAYA: At 12.41am, the Malaysia Airlines (MAS) red-eye service to Beijing takes off from the KL International Airport with over 200 sleepy passengers.
Once airborne, the autopilot that will fly the Boeing 777-200 aircraft according to the speed, direction and climb rate set by the pilot, is engaged. For the pilots, one of the priorities after take-off is to climb to the cruising altitude of about 10,668m (35,000ft) and ensure the aircraft maintains contact with ground control.
Forty minutes after take-off – which is when MH370 was reported to have lost radar contact yesterday at 1.30am – it would have been right at the Malaysia-Vietnam airspace boundary. Most of the internal lights would have been dimmed and the passengers would either be watching a movie or getting some sleep.
Pilots will set the aircraft’s radio frequency to the KLIA control tower at below 914.4m (3,000ft) and change it to the Kuala Lumpur ground station’s frequency once above that altitude.
When the aircraft hits 3,048m (10,000ft), the seatbelt sign comes off and passengers are free to move about.
Retired pilot Capt Lim Khoy Hing, in his walk-through of the first hour of the flight, said a “transfer process” would take place once it reached the boundary marking Malaysia and Vietnam airspace.
Lim, who flew the B777-200 model for MAS from 1997 to 2006 and has clocked 25,500 flying hours in a 44-year career, said Kuala Lumpur ground control will contact Ho Chi Minh to say that the aircraft is entering Vietnam’s airspace and that the pilot will be contacting them.
“If this is not done within several minutes, alarm bells will ring, meaning an aircraft cannot go ‘missing’ for more than 10 minutes,” the veteran pilot said.
It is not possible for the aircraft to run out of fuel so early in its flight.
Lim said he was not sure whether a mishap occurred during the transfer period as there was insufficient information.
“The only time I had a problem with the B777-200 model was when a faulty indicator forced me to turn back because we thought one of the doors was not properly sealed,” he said.
Pilots are trained to make the Mayday call as soon as they encountered an emergency and it takes about five minutes to bring the aircraft from cruising altitude to a safe height of 3,048m where passengers would not need an oxygen mask.
If pilots had the time to bring the aircraft down to a safe level, then they would also have the time to make the distress call.
“Pilots are trained to make the Mayday call and everyone in the same airspace on the same frequency will hear it and the first priority will be given to the plane so it can land safely,” said the veteran pilot.
Another pilot, Capt Alan Chan, said it took about 20 minutes for a B777-200 to climb to its cruising altitude, adding that the cruising mode was considered the safest period of the flight while the take-off and landing were the riskiest.
There are several methods for pilots to send a distress call, including through VHF and HF radio communication as well as the Controller-pilot data link communication (CPDLC).
“For VHF and HF, it would have been immediate as the pilots are talking to the controller. Using the CPDLC will take the same amount of time as typing an SMS.
“Whatever happened must have been so fast that they did not have time to sound the alert,” he said.
Chan said the aircraft should not have lost radar contact if it had been just a communications failure, as the transponder would have continued transmitting signals to let the controller know its location.