Malaysian Airlines MH370 contact lost
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@lakedude: agreed, in networking the ping is 'is anyone there?' so in order for a correct response the reply has to return to the originating address, therefore the ping must contain a unique ID.
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Re the fuel question -
"The plane had enough fuel to fly for a total of about seven-and-a-half to eight hours, Malaysia Airlines' Chief Executive Ahmad Jauhari Yahya said on Sunday."
"The plane had enough fuel to fly for a total of about seven-and-a-half to eight hours, Malaysia Airlines' Chief Executive Ahmad Jauhari Yahya said on Sunday."
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Its a good point Lakedude but just to throw a question back at you,
Malaysian Airlines apparently economically was not doing to good and airlines in that kind of climate tend to swap parts backwards and forwards between aircraft to keep them operational.
Is the part responsible for this ping swapped into another aircraft.
Also has any info on the other ping distances been released? Or are they all on the same arc.
Its been mentioned that they are only position fixes along that arc and not proof the plane was flying the arc.
What if all the pings are on the same arc....then it is quite conceivable that the pings are coming from exactly one stationery point! .....on the ground....at Kuala Lumpur
It cannot be discounted.
Malaysian Airlines apparently economically was not doing to good and airlines in that kind of climate tend to swap parts backwards and forwards between aircraft to keep them operational.
Is the part responsible for this ping swapped into another aircraft.
Also has any info on the other ping distances been released? Or are they all on the same arc.
Its been mentioned that they are only position fixes along that arc and not proof the plane was flying the arc.
What if all the pings are on the same arc....then it is quite conceivable that the pings are coming from exactly one stationery point! .....on the ground....at Kuala Lumpur
It cannot be discounted.
Last edited by xgjunkie; 17th Mar 2014 at 09:54. Reason: Dramatic effect
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"An Inmarsat official, while declining to discuss specifics of Flight 370, tells CNN the satellite system is highly reliable, that each signal to an aircraft is met by a return signal and that those signals always contains a code verifying the identity of the aircraft. It is "virtually impossible" to change an aircraft's identifying code or to confuse one aircraft with another, the Inmarsat official said."
Source: CNN
Source: CNN
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KL is not on the 40 degree circle. The signals would not be coming from there.
As far as I know the other ping details have not been released. They would be very useful for deducing a track.
As far as I know the other ping details have not been released. They would be very useful for deducing a track.
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Pinging
It's been discussed many posts back
Aircraft Pings Satellite " hello you there ? "
Satellite pings aircraft back " yes I'm here "
Then comes the handshake " ok let's do business"
Data transfer follows.
Aircraft Pings Satellite " hello you there ? "
Satellite pings aircraft back " yes I'm here "
Then comes the handshake " ok let's do business"
Data transfer follows.
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ana.KL is not on the 40 degree circle. The signals would not be coming from there.
As far as I know the other ping details have not been released. They would be very useful for deducing a track.
As far as I know the other ping details have not been released. They would be very useful for deducing a track.
Its pretty close, while I accept that it is not right on that line, its within the degree of error. Considering distance is calculated from the return ping then there will be a large fudge factor
Also the original distance was calculated with an aircraft at 35,000ft. Well recalculate that for sea level.
Last edited by xgjunkie; 17th Mar 2014 at 10:06. Reason: Additional
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@xgjunkie: if you were correct in your hypothesis that previous pings (the details of which have not been published) might also be on the same arc thereby indicating the possibility of a stationary aircraft, then surely the SAR efforts would be focussed on airfields positioned along those lines?
Not saying you are wrong, but just pushing back to test the logic of your thoughts.
Not saying you are wrong, but just pushing back to test the logic of your thoughts.
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The ping timings are very accurate. Expect accuracy of the order of 10 km or below (although details have not been released).
The satellite is roughly 40,000 km away so whether the aircraft is at altitude 0 or 12km does not make much difference.
The satellite is roughly 40,000 km away so whether the aircraft is at altitude 0 or 12km does not make much difference.
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Thanks OneTrack, I had not seen this previously but would be logical. I have been retired for a few years but unless SOPs re fuel had changed dramatically, 3 hour excess did not make sense - simply not economical.
If these reports are to be believed we have had the jet flying at varying altitudes up to FL450.
This would dramatically increase fuel consumption, so the 8 hour flight time seems exaggerated ........unless the last ping was received after fuel was exhausted, wherever that may be.
If these reports are to be believed we have had the jet flying at varying altitudes up to FL450.
This would dramatically increase fuel consumption, so the 8 hour flight time seems exaggerated ........unless the last ping was received after fuel was exhausted, wherever that may be.
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Strategically Australia will not want to divulge it's radar capabilities in full, so if they don't go looking or appear to only be putting in a token search effort, I suspect it will mean that the aircraft never came near Australia.
@SQGRANGE
I'll correct you. A commercial flight typically departs with trip fuel (6 hours as you have supposed) + alternate (some have assumed about 1 hour) + 10% contingency (about 40 mins based on the presumed figures) + final reserve (30 mins) + whatever the captain deems appropriate, having good knowledge of most aspects he is likely to encounter on the flight.
If the flight continued until flame-out or into final reserve, the figures above come to over 8 hours, unuseable fuel and other factors aside.
On the contrary to your creative accountant supposition, I think someone is displaying confusion based on ignorance. You claim to be an ex 777 jockey - are you sure about that?
Correct me if I am wrong, but the jet supposedly has flown for 8 hours, with a certain amount of time at low altitude yet only had enough fuel to get to Beijing (slightly under 6 hours) and say 45 -60 minutes reserve?
I think someone is a creative accountant.
I think someone is a creative accountant.
If the flight continued until flame-out or into final reserve, the figures above come to over 8 hours, unuseable fuel and other factors aside.
On the contrary to your creative accountant supposition, I think someone is displaying confusion based on ignorance. You claim to be an ex 777 jockey - are you sure about that?
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I am a satellite communications engineer and just want to give a bit of insight on the ping data that was used to draw the two corridors.
First of all I want to comment that the ping data can provide a pretty accurate (within a few km) picture of the range of the target to the satellite. In that respect the target can be within a circle that has as a centre the sub satellite point. Someone also mentioned about multiple satellites just to remind that the inmarsat system uses geostationary satellites and there is just one that covers that part of the globe otherwise known as IOR (Indian Ocean Region)
The result corridors are not an outcome of just ping ranging but I would assume that they are correlated with other data. What I would have done is start from the last point of radar contact and draw a circle that would define all the possible locations of the aircraft at the time of the next ping. That circle would intersect to at least at one point the ranging circle see here that are defined by the next ping roundtrip delay. Then repeat the same for every ping I got and should end up with some locations across the final arc. Each one of them can have an associated probability by correlating the probabilities of altitude and ground speed of the plane.
I therefore see no problem at the depicted arcs, although I am sure certain locations or sub arcs have higher probabilities than the others. Good luck to them this is a very tough case.
First of all I want to comment that the ping data can provide a pretty accurate (within a few km) picture of the range of the target to the satellite. In that respect the target can be within a circle that has as a centre the sub satellite point. Someone also mentioned about multiple satellites just to remind that the inmarsat system uses geostationary satellites and there is just one that covers that part of the globe otherwise known as IOR (Indian Ocean Region)
The result corridors are not an outcome of just ping ranging but I would assume that they are correlated with other data. What I would have done is start from the last point of radar contact and draw a circle that would define all the possible locations of the aircraft at the time of the next ping. That circle would intersect to at least at one point the ranging circle see here that are defined by the next ping roundtrip delay. Then repeat the same for every ping I got and should end up with some locations across the final arc. Each one of them can have an associated probability by correlating the probabilities of altitude and ground speed of the plane.
I therefore see no problem at the depicted arcs, although I am sure certain locations or sub arcs have higher probabilities than the others. Good luck to them this is a very tough case.
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Originally Posted by VH-XXX
Strategically Australia will not want to divulge it's radar capabilities in full, so if they don't go looking or appear to only be putting in a token search effort, I suspect it will mean that the aircraft never came near Australia.
There's also a lot of things we as the public won't know that they (the investigators) do as well.
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Sensors
There has been discussion of what the Royal Malaysian Air Force (abbreviated to TDUM in the native language) did or did not do on the night when this frustrating, perplexing tragedy began.
A quick look suggests that the RMAF had its radars at Kuantan and Butterworth modernised in 2005 and that two Vera ESM units were introduced in 2007.
There has been mention of RMAF F-16s, only it appears their small but diverse fleet of combat aircraft includes Sukhoi Su-30s, F/A-18Ds and some Mig-29s. As recently as last year a sum of US$100 million was allocated to improving the Su-30s combat readiness from 65-70percent to 80percent or more.
Such data suggests the RMAF takes its role as providing aerial defence and airspace dominance of Malaysian airspace and territory seriously.
One of the characteristics (to which I am of course adding) of posts on this topic is that they come from civilian people based far away from Malaysia so views on what may or may not have occurred within RMAF bases that night are unlikely to be highly accurate.
It would appear, though, that the country does possess the sensors and the aircraft to have responded to a radar track not exhibiting normal identification and not conforming to a scheduled or filed flight plan, although the time to do so would perhaps have provided little opportunity to do so.
Only the country always was and remains relatively narrow, so the timings are always going to be squeezed and presumably the air defence system is rigged accordingly, if only in theory.
A quick look suggests that the RMAF had its radars at Kuantan and Butterworth modernised in 2005 and that two Vera ESM units were introduced in 2007.
There has been mention of RMAF F-16s, only it appears their small but diverse fleet of combat aircraft includes Sukhoi Su-30s, F/A-18Ds and some Mig-29s. As recently as last year a sum of US$100 million was allocated to improving the Su-30s combat readiness from 65-70percent to 80percent or more.
Such data suggests the RMAF takes its role as providing aerial defence and airspace dominance of Malaysian airspace and territory seriously.
One of the characteristics (to which I am of course adding) of posts on this topic is that they come from civilian people based far away from Malaysia so views on what may or may not have occurred within RMAF bases that night are unlikely to be highly accurate.
It would appear, though, that the country does possess the sensors and the aircraft to have responded to a radar track not exhibiting normal identification and not conforming to a scheduled or filed flight plan, although the time to do so would perhaps have provided little opportunity to do so.
Only the country always was and remains relatively narrow, so the timings are always going to be squeezed and presumably the air defence system is rigged accordingly, if only in theory.
