The Flight-Following System which supposedly tracks a flying aircraft’s position is based on a “projection” data and not the actual aircraft position.

This was clarified by Malaysia Airlines (MAS) in a media statement late Friday.

The clarification came after questions arose about the exchange of signals between ground and the aircraft soon after Ho Chi Minh Air Traffic Control advised that radio contact had not been established with MH370, as carried in the recently released MH370 Preliminary Report.

In the statement, MAS explained that what was referred to as signals was actually the aircraft displayed on the ‘Flight-Following System’ screen, which was based on the aircraft projection at that point of time and not the actual aircraft position.

“When KL-ATCC (Kuala Lumpur Air Traffic Control Centre) Watch Supervisor queried Malaysia Airlines OPS (Operations) on the status of MH370, Malaysia Airlines OPS informed KL-ATCC Supervisor that MH370 was still sighted over Cambodian airspace in the Flight-Following System, which is based on a flight-projection.

“The word ‘Cambodia’ was displayed by the Flight-Following System on the screen when zoomed-in, leading Malaysia Airlines to deduce that the aircraft was flying in Cambodian airspace. The Flight-Following System did not display the name ‘Vietnam’, even though the aircraft was over Vietnam airspace,” said the statement.

It was previously reported that confusion arose when the Flight-Following System showed the location of flight MH370 being within Cambodian airspace, when the area is not part of the flight path from Kuala Lumpur to Beijing.

MAS said the responsibility of aircraft tracking monitoring resides with Air Traffic Control Centres. “For airlines, it is normal to engage flight-following systems to assist its pilots to manage in weather conditions or route diversions.”

If there was any abnormality with or within the aircraft, the Flight-Following System would not show it; updates on such situations need to be pilot initiated, MAS said. “Unless otherwise, airlines’ operations control centres would continue to see the aircraft as flying on its normal route, based on projected or predicted positions and locations.”

MAS said to make the flight-following systems work successfully and effectively, it was important to have visual depiction of the aircraft’s position coupled with confirmation by air-to-ground communications, such as through ACARS or Satcomm or VHF or HF.

In the case of tracking MH370, MAS’ Flight-Following System indicated that the aircraft was flying, however, there was no communication from or with the pilot. “Malaysia Airlines OPS attempted to communicate with MH370 after we were flag by KL-ATCC, but was never able to make contact.”