Malaysian Airlines MH370 contact lost

[sandos]

Originally Posted by Blacksheep

there is absolutely no way that the scientists producing their range predictions, based on analysis of "handshake" responses that were never intended for range determination, could know the internal condition of the airborne components of the Satcom system

They don't really need to know the exact condition: they could use the "pings" on ground, when the satcom gear is in a known location, to calibrate from. Barring extreme drift during flight, this should be very accurate.

[AT1]

Blacksheep

A one microsecond variation within the airborne equipment's processing circuits could easily result in a 2,000 km error in the position calculation.

Light (and radio waves) moves quickly. I cannot keep up with it.

But. The speed of light is approx 3 x 10^8 metres per second. One microsecond is 1 x 10^-6 seconds.
So, in one microsecond light (and radio) will travel approx 3 x 10^2 metres.
At an "altitude" of 40 degrees - lets change that to 45 degrees to keep it simpe - a 300 metre variation in the hypotenuse would mean, roughly, a 200 metre variation in the horizontal position.

Is my maths wrong? If not, hardly 2,000Km.

And as has already been posted, while the equipment may not be bench calibrated , Inmarsat are very likely to have had similar "ping" data from when the plane's postion was known with considerable precision - as when on the ground - to calibrate their analysis.

There will, of course, be variances between different pieces of equipment. An individual piece of equipment will also have variations over time. But do not underestimate the sophistication of the equipment, particularly of the complete end to end comms system including the plane mounted equipment, the orbiter and the ground station. Or the capabilities, experience, and intelligence of the people that have carried out the analysis.

[hikoushi]

Has there been any discussion regarding the background checks of the flight attendants? Certainly they would be somewhat familiar with the cockpit layout from sitting in there while the pilots go on bathroom breaks. If one of them had ill intentions and a modicum of flight-simulator experience they could easily have murdered the remaining pilot (using the axe or any other heavy object) while the other was outside, and initiate a sequence of events leading to this aircraft's disappearance. An FA with a long-stewing intention of accomplishing something like this could gain all the information they would need to shut off various systems (communication, dump cabin pressure, etc) simply by asking questions while seated in the cockpit over various flights. Not to mention studying any number of websites and messing around with X-Plane or whatever.

Let's face it it's not rocket science here. Pull a couple of circuit breakers, put on an O2 mask, manipulate some cabin pressure controls to dump the cabin, turn the altitude knob and pull, type a few keystrokes into the FMS, and that's it. A little homework is all it would take.

If according to the latest (CNN so take it with a grain of salt) all passengers and the pilots have been cleared of suspicion yet they are STILL viewing the aircraft's maneuvers as a "criminal act", then that basically just leaves the cabin crew, correct?

[the incivil beast]

That might make sense until :

The Captain climbs to 45,000', DPs, and kills all others onboard

Then, that could fit with information publicly available :
Flies around Indonesian airspace
Turns the heading knob to 180 and drops O2 mask ...

[Passagiata]

DH call:

So will the Chinese government foot the bill in this search effort or are they just going to sit back and enjoy the moment as the victims families blame every non-chinese government or organization for the lack of results in this search?

No, they are not obliged to. The countries who have contributed to the search will foot their own bills initially I would think. So China will be paying for any of its aircraft that it is using. Whether any bills would end up being charged to the airliner's insurers, I don't know. Australia will pay for all of its S&R efforts, eg those inside its S&R zone.

[glad rag]

Take a look at the Malaysian PMs demeanour while in Australia
He knows it is not in the Southern Ocean

Don't suppose you have any kind of PROOF or INDICATION to support this?

BTW I am keeping a very open mind on this sad event, but really..........

[Mahatma Kote]

But. The speed of light is approx 3 x 10^8 metres per second. One microsecond is 1 x 10^-6 seconds.

To simplify it even further. Light travels roughly one foot per nanosecond.

One microsecond is 1000 nanoseconds.

One microsecond is ~ 1000 feet not 6,561,679 feet 9 31⁄64 inches (2000 km)

[500N]

So will the Chinese government foot the bill in this search effort or are they just going to sit back and enjoy the moment as the victims families blame every non-chinese government or organization for the lack of results in this search?

I haven't seen any or much criticism of Australia's efforts, or for that matter Vietnam, India who although the last two got tardy with Malaysia, who could blame them.

Apart from the number of Chinese being involved, the other MAJOR reason for China's huge response is because they got whipped badly a few years back for the tardy Chinese response to helping out a neighbour when every other country in the world put all hands to the grind stone !

They (the Chinese) didn't like it and were determined to make sure that type of criticism didn't happen again.

Re costs, remember the military costs are incurred whether they are searching for the aircraft or doing normal flying duties or sitting on the flight line.

[Ian W]

Originally Posted by portmanteau

ian w . your theory of little or no interest in an aircraft wandering around the skies might have some validity if the disinterested parties were unaware that an aircraft was missing. 370 was known to be missing at the time it should have contacted vietnam and it is inconceivable that the word did not reach all parts of se asia in a very short time. all surrounding atccs would be on alert for the aircraft on radio and radar. interest would be of a very high order I would say.

It would take sometime for the news to be shared with other civil units, sharing with the military would take longer if at all. Remember, the immediate thoughts were that the aircraft had dissappeared somewhere en-route to Vietnam at the extreme edge of Malaysian radar cover. Why contact internal military units to look for an aircraft that was assumed to be either en-route more than 200 miles away with some complex comms failure? After half an hour or so it was assumed that the aircraft was in the South China Sea again, why contact military? It was only when the news got out after seveal hours that the military said we think that one flew back overland out into the Malacca Straights. This was reported but then Iwould think the question was "are you absolutely sure?" - so while it was being checked the 'civilian loss of radar' contact was given as the time of last radar. Only when the military had time to pull the tapes and recheck did the time go back to 2:40 loss of primary radar over the Malacca Straights.

I see nothing suspicious in this although the management of information to the baying media could have been better handled.

[londonman]

@9151 martynemh

Let's get it right -

Radios etc were not 'switched off', they stopped working.

Can I ask for clarification? If you are saying that no-one knows if the radios were switched off then I agree. However, your post could be read that the radios were not switched off because they broke down...then I disagree as how can anyone on the ground know that?

[martynemh]

@9190 Londonman.

We cannot know that assorted radios etc were swtched off. All that we know is that, for example, the Transponder/s stopped giving out info, and none of the VHF radios transmitted any more, nor did the ACARS perform later on. We have no info that says 'Radios were switched off'.

And we still don't get to see the cargo manifest (which of course might not be accurate, in that some 'goods' might not have been manifested), nor have we got any access to the military radar records of several, probably useful, surrounding nations - as well as that of Malaysia itself.

[James7]

Re create flight.

Best suggestion I have seen on CNN, FAA chap talking about recreating the flight, according to the Pings, to try and narrow down possible crash site.

Will have to use the exact same equipment.

Should have been done weeks ago.

[L337]

You can't lock the other pilot out and depressurise because the cockpit door will open even if holding lock.

That is incorrect, and has been covered earlier in the thread... the blow out panels will open, but the door will remain locked

[Lonewolf_50]

We only know that none of the radios transmitted anymore on the frequency in use or 121.5.

FWIW, "we" also know that the 01:37 ACARS data was not transmitted. As I understand how MAL was applying ACARS, they used the VHF option, not the satellite option.

That info and a buck fifty might get us a cup of coffee.

[portmanteau]

Ian w. my reply to lonewolf 50 was modded out but I have to advise both of you of what goes on in atc from personal hands on experience. worldwide procedures as laid down by ICAO would have been followed by on-watch atcos in the KL and Ho Chi Minh FIRs immediately following the aircraft's disappearance which was when it failed to contact HCM. Search and Rescue action, mandated by ICAO, is usually devolved to military units since the states involved will not usually want to maintain specialised civil aircraft for this task. hence the military air forces in KL and vietnam would be in the loop immediately followed by those of other surrounding atccs.
It is likely that Lumpur Radar on 132.6 who was controlling 370 at the handover point, would have been looking at a feed from Khota Bharu radar whose cover stretches almost to the vietnamese coast. meanwhile HCM's radar cover reached at least to the handover point if their report of observing a turnback is correct, so I think 370 was not out of radar cover at any time. this would have considerably shortened any uncertainty time. look up incerfa/alerfa/detresfa... all will be revealed in the accident report and not before, at least to us onlookers and the media.

[DocRohan]

one thing that still puzzles me.....AAIB say that 6 complete handshake were analyzed to plot the possible route after ACARS was disabled....So we "assume" that the 18:25 and 18:28 pings may have not been complete pings (????) Would that then make it difficult to accurately determine the doppler offset frequency if they were not complete pings??...One of these is the "possible turn" ping, so it could be even more important!
I still dont understand why anyone would release a statement saying 6 pings, then release a chart that shows 8?!!!

[takata]

Noise...

Hi,
I do remember the very high level of speculations following AF447 tragedy, and also that most of it (if not all of it) was simply based on false assumptions due to erroneous media releases, usually sourced from unknown people being 'familiar with the investigation'. Even those preliminary reports were not convincing people that no Airbus/BEA 'cover up' was taking place...

As I'm trying to cross-check some of the facts concerning MH370 published so far, it appears that the same context is producing exactly the same effects:

i.e.: those radar data showing:
- sharp turn... or shallow turn(s)?
- altitude changes ranging from 12,000 (or 23,000) to 45,000 ft... or no change from cruising altitude?


Check the previously posted link here: MH370 wreckage, probable cause may never be found, says ex-NTSB investigator | Leeham News and Comment
interview with Greg Feith, a former investigator for the National Transportation Safety Board
Source: Aviation Week.

As for the related theory that the auto pilot took over after the crew was disabled by hypoxia, the series of left and right hand turns belies this, he said. If the crew were overcome, the airplane would have continued on its original course to Beijing. Instead, it made a “shallow” left turn after its last radio communication with Malaysian Air Traffic Control to a new course almost behind its original course. Then, over the Strait of Malacca, it made a right turn, a left turn and another left turn going south over the Indian Ocean.

Citing his sources familiar with the investigation, Feith said these were shallow banks of perhaps 20 degrees, normal turns that would not have alerted passengers that anything was out of the ordinary.

“The auto pilot isn’t smart enough [on its own] to make the maneuvers the airplane did,” Feith said.

All the altitude changes that have been reported in the media are incorrect, he said, citing his sources. The airplane never left its cruising altitude of 35,000 ft.

Well, I would wait for the first report to be released in order to check out what they really come up with...

[RUTUS]

Originally Posted by AT1

...
And as has already been posted, while the equipment may not be bench calibrated , Inmarsat are very likely to have had similar "ping" data from when the plane's postion was known with considerable precision - as when on the ground - to calibrate their analysis.
...

"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."

Tuesday, March 25, 06:50 PM MYT +0800 Malaysia Airlines MH370 Flight Incident

MH370 Flight Incident | Malaysia Airlines (as of today on dynamic page 3)

[Lonewolf_50]

Originally Posted by portmanteau

Ian w. my reply to lonewolf 50 was modded out but I have to advise both of you of what goes on in atc from personal hands on experience. worldwide procedures as laid down by ICAO would have been followed by on-watch atcos in the KL and Ho Chi Minh FIRs immediately following the aircraft's disappearance which was when it failed to contact HCM.

Would have been. How long does "immediately" take in your experience? I appreciate your familiarity with ICAO standards and with air traffic control. That doesn't answer the question originally posed.

Search and Rescue action, mandated by ICAO, is usually devolved to military units since the states involved will not usually want to maintain specialised civil aircraft for this task. hence the military air forces in KL and vietnam would be in the loop immediately followed by those of other surrounding atccs.

Again, how long does "immediately" take in your experience?

It is likely that Lumpur Radar on 132.6 who was controlling 370 at the handover point, would have been looking at a feed from Khota Bharu radar whose cover stretches almost to the vietnamese coast.

Aye.

meanwhile HCM's radar cover reached at least to the handover point if their report of observing a turnback is correct, so I think 370 was not out of radar cover at any time.

OK. This explains HCM contacting Maylaysian POC when they didn't get a check in.

this would have considerably shortened any uncertainty time. look up incerfa/alerfa/detresfa... all will be revealed in the accident report and not before, at least to us onlookers and the media.

Am familiar with those terms, thanks.

[Datayq1]

VHF vs. Satcom

@lonewolf:

As I understand how MAL was applying ACARS, they used the VHF option, not the satellite option.

That is what I surmised as well, however the Inmarsat provides a datum at 17:07 for satcom. Is that coincidential with the ACARS-VHF transmission, or is it possible that the ACARS tx was echoed by satcom?