Analysis done by Inmarsat and AAIB was convincing to conclude on MH370's last position, says Hishammuddin Hussein.
PETALING JAYA: Acting Transport Minister Hishammuddin Hussein provided more information today on the new analysis based on satellite data that concluded that Malaysia Airlines Flight MH370 did indeed end in the southern Indian Ocean.
Last night, Prime Minister Najib Tun Razak said the new analysis of satellite data from Inmarsat and UK Air Accidents Investigation Branch (AAIB) concluded that MH370 ended in the southern Indian Ocean.
The new analysis considers the velocity of the aircraft relative to the satellite.
Depending on this relative movement, the frequency received and transmitted will differ from its normal value, in much the same way that the sound of a passing car changes as it approaches and passes by. This is called the Doppler effect.
The Inmarsat technique analyses the difference between the frequency that the ground station expects to receive and one that is actually measured.
This difference is the result of the Doppler effect and is known as the Burst Frequency Offset.
The Burst Frequency Offset changes depending on the location of the aircraft on an arc of possible positions, its direction of travel, and its speed.
In order to establish confidence in its theory, Inmarsat checked its predictions using information obtained from six other B777 aircraft flying on the same day in various directions. There was good agreement.
Flight MH370 transmitted several messages during the early stage to the Kuala Lumpur Internationl Airport.
At this stage, the location of the aircraft and the satellite were known, so it was possible to calculate system characteristics for the aircraft, satellite, and ground station.
During the flight, the ground station logged the transmitted and received pulse frequencies at each handshake. Knowing the system characteristics and position of the satellite it was possible, considering aircraft performance, to determine where on each arc the calculated burst frequency offset fit best.
The analysis showed poor correlation with the Northern corridor, but good correlation with the southern corridor, and depending on the ground speed of the aircraft it was then possible to estimate positions at which the last complete handshake took place.
MH370′s final position
Hishammudin, however, emphasised that this was not the final position of the aircraft.
“There is evidence of a partial handshake between the aircraft and ground station. At this time this transmission is not understood and is subject to further ongoing work,” he said.
No response was received from the aircraft at 0115 UTC, when the ground earth station sent the next log on/log off message. This indicates that the aircraft was no longer logged on to the network.
Therefore, sometime between 0011 UTC and 0115 UTC the aircraft was no longer able to communicate with the ground station. This is consistent with the maximum endurance of the aircraft.
This analysis by Inmarsat forms the basis for further study to attempt to determine the final position of the aircraft.
Accordingly, the Malaysian investigation has set up an international working group, comprising agencies with expertise in satellite communications and aircraft performance, to take this work forward.
Hishammuddin said the analysis was convincing enough for the AAIB to brief the Prime Minister that MH370 flew along the southern corridor, and that its last position was in the middle of the Indian Ocean, west of Perth.
“As the Prime Minister stated, this type of analysis has never been done in an investigation of this sort.
“There remains more work to be done, and we are grateful to Inmarsat, AAIB and the international investigations team, who are continuing to work with the Malaysian authorities.
“This is a developing situation, and as soon as we know more, we will share it,” said Hishammuddin.
Hishammuddin’s explanation today comes at a time when family members of the missing passengers are demanding for concrete and tangible proof that their loved ones had perished in a crash, if at all there has been a crash.
Search efforts in the new target area in southern Indian Ocean were called off today due to bad weather and is set to continue tomorrow with searchers trying to gain possession of two objects found floating two days ago.
MH370 disappeared from the radar on March 8 while on its journey from KLIA to Beijing, carrying 239 passengers and crew members.
Investigators found that the plane’s communications and transponder were deliberately disabled, and the plane flying away from its original journey towards the Indian Ocean.
Last night, Prime Minister Najib Tun Razak said the new analysis of satellite data from Inmarsat and UK Air Accidents Investigation Branch (AAIB) concluded that MH370 ended in the southern Indian Ocean.
The new analysis considers the velocity of the aircraft relative to the satellite.
Depending on this relative movement, the frequency received and transmitted will differ from its normal value, in much the same way that the sound of a passing car changes as it approaches and passes by. This is called the Doppler effect.
The Inmarsat technique analyses the difference between the frequency that the ground station expects to receive and one that is actually measured.
This difference is the result of the Doppler effect and is known as the Burst Frequency Offset.
The Burst Frequency Offset changes depending on the location of the aircraft on an arc of possible positions, its direction of travel, and its speed.
In order to establish confidence in its theory, Inmarsat checked its predictions using information obtained from six other B777 aircraft flying on the same day in various directions. There was good agreement.
Flight MH370 transmitted several messages during the early stage to the Kuala Lumpur Internationl Airport.
At this stage, the location of the aircraft and the satellite were known, so it was possible to calculate system characteristics for the aircraft, satellite, and ground station.
During the flight, the ground station logged the transmitted and received pulse frequencies at each handshake. Knowing the system characteristics and position of the satellite it was possible, considering aircraft performance, to determine where on each arc the calculated burst frequency offset fit best.
The analysis showed poor correlation with the Northern corridor, but good correlation with the southern corridor, and depending on the ground speed of the aircraft it was then possible to estimate positions at which the last complete handshake took place.
MH370′s final position
Hishammudin, however, emphasised that this was not the final position of the aircraft.
“There is evidence of a partial handshake between the aircraft and ground station. At this time this transmission is not understood and is subject to further ongoing work,” he said.
No response was received from the aircraft at 0115 UTC, when the ground earth station sent the next log on/log off message. This indicates that the aircraft was no longer logged on to the network.
Therefore, sometime between 0011 UTC and 0115 UTC the aircraft was no longer able to communicate with the ground station. This is consistent with the maximum endurance of the aircraft.
This analysis by Inmarsat forms the basis for further study to attempt to determine the final position of the aircraft.
Accordingly, the Malaysian investigation has set up an international working group, comprising agencies with expertise in satellite communications and aircraft performance, to take this work forward.
Hishammuddin said the analysis was convincing enough for the AAIB to brief the Prime Minister that MH370 flew along the southern corridor, and that its last position was in the middle of the Indian Ocean, west of Perth.
“As the Prime Minister stated, this type of analysis has never been done in an investigation of this sort.
“There remains more work to be done, and we are grateful to Inmarsat, AAIB and the international investigations team, who are continuing to work with the Malaysian authorities.
“This is a developing situation, and as soon as we know more, we will share it,” said Hishammuddin.
Hishammuddin’s explanation today comes at a time when family members of the missing passengers are demanding for concrete and tangible proof that their loved ones had perished in a crash, if at all there has been a crash.
Search efforts in the new target area in southern Indian Ocean were called off today due to bad weather and is set to continue tomorrow with searchers trying to gain possession of two objects found floating two days ago.
MH370 disappeared from the radar on March 8 while on its journey from KLIA to Beijing, carrying 239 passengers and crew members.
Investigators found that the plane’s communications and transponder were deliberately disabled, and the plane flying away from its original journey towards the Indian Ocean.
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