Re: Malaysia Airlines Plane is Missing
Correction: It was a Tu-134. The Tu-144 is a very different aircraft.
Malaysia Airlines Flight 370 is Missing
- Thread starter no_name
- Start date
Quickie
Colonel
Re: Malaysia Airlines Plane is Missing
Much work was done by the experts to come to the conclusion.
Published: Tuesday March 25, 2014 MYT 6:35:00 PM
Updated: Tuesday March 25, 2014 MYT 6:54:33 PM
MH370 crash: Hisham on how it was concluded that flight ended in south Indian Ocean
PETALING JAYA: Malaysia concluded that Flight MH370 ended in the southern part of the Indian Ocean using data that was analysed by Inmarsat and UK's Air Accidents Investigation Branch (AAIB), said acting Transport Minister Datuk Seri Hishammuddin Hussein.
Here is an excerpt of the statement read out by Hishammuddin at the daily press briefing at PWTC on Tuesday:
"In recent days Inmarsat developed a second innovative technique which 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 that 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.
While on the ground at Kuala Lumpur airport, and during the early stage of the flight, MH370 transmitted several messages. 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 0011 UTC, at which the last complete handshake took place. I must emphasise that this is not the final position of the aircraft.
There is evidence of a partial handshake between the aircraft and ground station at 0019 UTC. At this time this transmission is not understood and is subject to further ongoing work.
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.
Technical background
The new analysis I have described above 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. Within a few hours, the families had been informed, and the prime minister announced the new development to the world."
Much work was done by the experts to come to the conclusion.
Published: Tuesday March 25, 2014 MYT 6:35:00 PM
Updated: Tuesday March 25, 2014 MYT 6:54:33 PM
MH370 crash: Hisham on how it was concluded that flight ended in south Indian Ocean
PETALING JAYA: Malaysia concluded that Flight MH370 ended in the southern part of the Indian Ocean using data that was analysed by Inmarsat and UK's Air Accidents Investigation Branch (AAIB), said acting Transport Minister Datuk Seri Hishammuddin Hussein.
Here is an excerpt of the statement read out by Hishammuddin at the daily press briefing at PWTC on Tuesday:
"In recent days Inmarsat developed a second innovative technique which 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 that 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.
While on the ground at Kuala Lumpur airport, and during the early stage of the flight, MH370 transmitted several messages. 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 0011 UTC, at which the last complete handshake took place. I must emphasise that this is not the final position of the aircraft.
There is evidence of a partial handshake between the aircraft and ground station at 0019 UTC. At this time this transmission is not understood and is subject to further ongoing work.
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.
Technical background
The new analysis I have described above 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. Within a few hours, the families had been informed, and the prime minister announced the new development to the world."
Last edited:
broadsword
Brigadier
Re: Malaysia Airlines Plane is Missing
Search Crews Will Need To Pinpoint A Small Crash Site To Find The Black Box Signal From MH370
Alex Heber, Business Insider Australia Mar. 25, 2014, 6:49 AM 168
REUTERS/Jason Reed
The window is closing to locate the black box of the missing Malaysian Airlines flight which disappeared 16 days ago but to pinpoint its location search crews need to narrow a search area to within tens of kilometres, an aviation expert says.
Now that authorities have concluded flight MH730 ended up in the Southern Indian Ocean, they are focusing on trying to find any debris and track currents to try and determine where the plane may have crashed into the water with its 239 passengers and crew.
But the search area is a vast region some 2,500km southwest of Perth, and the critical flight data recorder – one of two “black boxes” from the plane – has only two weeks of battery life left.
Once it runs out of battery it’s going to be almost impossible to retrieve it, according to Jason Middleton, Head of UNSW Aviation School – but in order to find it search crews are going to have to get very close to the object at first.
The boxes are fitted with acoustic pingers which send out an audio signal that sonar can detect.
“Sonar receivers can hear pings if they’re tens of kilometres away – not hundreds,” he said.
“This is why the US has dispatched ships with specialist equipment.
“There’s only a limited window to find the pinger. Once pingers lose battery, you’re done.”
The black box will contain critical flight data that will help establish what happened to the Malaysian Airlines jet after it took off from Kuala Lumpur on March 8.
“You can see whether settings have been turned off, if there was a fire or any malfunctions,” Middleton said.
The cockpit voice recorder might also “may tell something if the pilots are talking”.
He said locating debris from a wreckage was important but if the wreckage was found in the ocean, search crews would still need to review two weeks of current data to estimate a wreckage location.
“Then they have to look and listen to the pinger but they’ve only got two weeks,” he said.
“The trouble is it’s so remote.
“Pingers are very effective when you know where the accident is.”
If the back box is found it could be in very deep ocean so efforts to recover it would probably involve remote operated vehicles, Middleton said.
Search Crews Will Need To Pinpoint A Small Crash Site To Find The Black Box Signal From MH370
Alex Heber, Business Insider Australia Mar. 25, 2014, 6:49 AM 168
REUTERS/Jason Reed
The window is closing to locate the black box of the missing Malaysian Airlines flight which disappeared 16 days ago but to pinpoint its location search crews need to narrow a search area to within tens of kilometres, an aviation expert says.
Now that authorities have concluded flight MH730 ended up in the Southern Indian Ocean, they are focusing on trying to find any debris and track currents to try and determine where the plane may have crashed into the water with its 239 passengers and crew.
But the search area is a vast region some 2,500km southwest of Perth, and the critical flight data recorder – one of two “black boxes” from the plane – has only two weeks of battery life left.
Once it runs out of battery it’s going to be almost impossible to retrieve it, according to Jason Middleton, Head of UNSW Aviation School – but in order to find it search crews are going to have to get very close to the object at first.
The boxes are fitted with acoustic pingers which send out an audio signal that sonar can detect.
“Sonar receivers can hear pings if they’re tens of kilometres away – not hundreds,” he said.
“This is why the US has dispatched ships with specialist equipment.
“There’s only a limited window to find the pinger. Once pingers lose battery, you’re done.”
The black box will contain critical flight data that will help establish what happened to the Malaysian Airlines jet after it took off from Kuala Lumpur on March 8.
“You can see whether settings have been turned off, if there was a fire or any malfunctions,” Middleton said.
The cockpit voice recorder might also “may tell something if the pilots are talking”.
He said locating debris from a wreckage was important but if the wreckage was found in the ocean, search crews would still need to review two weeks of current data to estimate a wreckage location.
“Then they have to look and listen to the pinger but they’ve only got two weeks,” he said.
“The trouble is it’s so remote.
“Pingers are very effective when you know where the accident is.”
If the back box is found it could be in very deep ocean so efforts to recover it would probably involve remote operated vehicles, Middleton said.
solarz
Brigadier
Re: Malaysia Airlines Plane is Missing
If we were to apply Occam's Razor, I think the simplest and most likely explanation is that there was a malfunction on the plane that incapacitated the crew and passengers. The malfunction was detected by the pilots before they were incapacitated, who decided to turn the plane back, and thus reprogrammed the autopilot. However, because they were under duress, or were incapacitated shortly after, the autopilot was programmed incorrectly and the plane flew into the Indian Ocean.
If we were to apply Occam's Razor, I think the simplest and most likely explanation is that there was a malfunction on the plane that incapacitated the crew and passengers. The malfunction was detected by the pilots before they were incapacitated, who decided to turn the plane back, and thus reprogrammed the autopilot. However, because they were under duress, or were incapacitated shortly after, the autopilot was programmed incorrectly and the plane flew into the Indian Ocean.
Re: Malaysia Airlines Plane is Missing
Some remarks:
Civilian aircraft maintain a cabin pressure equivalent to the atmospheric pressure at 8000 ft altitude. If an aircraft goes over its rated altitude it may not be able to maintain that cabin pressure but their is no reason why it will loose all cabin over pressure unless the hull was breached. This means that no people or only a few would be knocked out by the loss of air pressure.
Looking for floating debris far out at sea might more easily been done using a medium size airship, say about 50 tons or even less, with an endurance of a week or more. When considering producing airships this is one use to think of.
Looking for debris on the bottom of the ocean might take years, as it did in the case of the Air France plane. China might do well to produce a number of autonomous unmanned submersibles to map that area of Indian Ocean bottom using side scan sonar.
Some remarks:
Civilian aircraft maintain a cabin pressure equivalent to the atmospheric pressure at 8000 ft altitude. If an aircraft goes over its rated altitude it may not be able to maintain that cabin pressure but their is no reason why it will loose all cabin over pressure unless the hull was breached. This means that no people or only a few would be knocked out by the loss of air pressure.
Looking for floating debris far out at sea might more easily been done using a medium size airship, say about 50 tons or even less, with an endurance of a week or more. When considering producing airships this is one use to think of.
Looking for debris on the bottom of the ocean might take years, as it did in the case of the Air France plane. China might do well to produce a number of autonomous unmanned submersibles to map that area of Indian Ocean bottom using side scan sonar.
Re: Malaysia Airlines Plane is Missing
Are you also suggesting that China build a Sonus network on the SCS and Indian Ocean as well? to find where to Kilos are?
Are you also suggesting that China build a Sonus network on the SCS and Indian Ocean as well? to find where to Kilos are?
airsuperiority
Captain
Re: Malaysia Airlines Plane is Missing
Since there's only 2 weeks left to look for the crash site, will there be enough time at all to find the plane on time? Can the USN or the Australian Navy or even the PLAN deploy more assets to the area to search for the plane?
Since there's only 2 weeks left to look for the crash site, will there be enough time at all to find the plane on time? Can the USN or the Australian Navy or even the PLAN deploy more assets to the area to search for the plane?
Re: Malaysia Airlines Plane is Missing
One would think that in handling this kind of situation that Malaysia would be sharing the information leading to a conclusion with everyone involved when they declare that conclusion. Otherwise it might as well be you or I declaring a conclusion.
One would think that in handling this kind of situation that Malaysia would be sharing the information leading to a conclusion with everyone involved when they declare that conclusion. Otherwise it might as well be you or I declaring a conclusion.
Re: Malaysia Airlines Plane is Missing
I didn't say anything about mid-air interception so you can save your personal attacks for someone else. Was there any attempt to even communicate with the unidentified aircraft when this was happening? That seems pretty basic to me, I hope that doesn't require going all the way up the chain of command.
I didn't say anything about mid-air interception so you can save your personal attacks for someone else. Was there any attempt to even communicate with the unidentified aircraft when this was happening? That seems pretty basic to me, I hope that doesn't require going all the way up the chain of command.