AirAsia flight QZ8501: Flight's communication with Singapore part of standard protocol

Air traffic controllers work inside the iconic Changi Airport control tower. Singapore air traffic control was informed by Jakarta when the pilot of AirAsia Indonesia Flight QZ8501 requested for approval to take the plane up to 38,000 feet. -- S
Air traffic controllers work inside the iconic Changi Airport control tower. Singapore air traffic control was informed by Jakarta when the pilot of AirAsia Indonesia Flight QZ8501 requested for approval to take the plane up to 38,000 feet. -- ST PHOTO: DESMOND LIM

SINGAPORE - Singapore air traffic control was informed by Jakarta when the pilot of AirAsia Indonesia Flight QZ8501 requested for approval to take the plane up to 38,000 feet.

Responding to queries from The Straits Times, a spokesman for the Civil Aviation Authority of Singapore (CAAS) said that the communication was part of standard protocol.

"As the Singapore Flight Information Region (FIR) was QZ8501's onward destination, Jakarta air traffic control informed Singapore air traffic control of the change in altitude as part of normal procedure."

Singapore air traffic control "immediately acknowledged the receipt of information" she added.

The exchange comprising Jakarta's communication to Singapore and Singapore's response, took seven seconds, from 7:17:06 to 07:17:13 Singapore time on Sunday morning, she added.

The Jakarta Post had earlier reported that the communication lasted two to three minutes.

The director of air navigation operator, AirNav Indonesia, Wisnu Darjono, was quoted saying that the aircraft had requested permission from Soekarno-Hatta Airport's air traffic control to turn left at 6.12am local time - an hour behind Singapore time - to avoid a storm.

The pilot of the Airbus 320 aircraft which was flying from Surabaya to Singapore with 162 passengers and crew members then requested to take the plane higher to 38,000 feet from its position at 32,000 feet.

"Request to higher level," said the pilot, according to Wisnu, to which the air traffic controller replied, "intended to what level?".

The pilot stated that he intended to rise to 38,000 feet but did not explain why he wished to fly higher.

Jakarta's air traffic control then contacted Singapore air traffic control.

Mr Wisnu was quoted as saying: "It took us around two to three minutes to communicate with Singapore. We agreed to allow the plane to increase its height but only to 34,000 feet, because at that time (another) AirAsia flight... was flying at 38,000 feet.

"But when we informed the pilot of the approval at 6:14am, we received no reply."

At that point, the aircraft was about 35 minutes away from Singapore air space, The Straits Times understands.

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