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-   -   Malaysian Airlines MH370 contact lost (https://www.pprune.org/rumours-news/535538-malaysian-airlines-mh370-contact-lost.html)

OPENDOOR 11th Mar 2014 22:43


Latest Twitter excitement via the Tomnod project.

Malaysia Airlines MH370 / TomNod crowd-search - CNN iReport

No idea about the scale.
Looks strangely like a ship, from the on-screen scale, about 175' long.

dfens42 11th Mar 2014 22:48

OPENDOOR:

175' is about right for a 777 also. Just saying

bubbers44 11th Mar 2014 22:52

Pilot oxygen mask failure post. I picked up a B737 one day in the afternoon and flew it several legs and the next morning we got the same aircraft. Doing our first flight of day checks hit the 100% flow button and guess what? After two seconds the flow stopped. Maintenance had replaced the bottle the day before and didn't turn the valve on. All we had was trapped line pressure the previous day.

PuraVidaTransport 11th Mar 2014 22:52

Interesting chart
 
Average Effective Performance Time for flying
personnel without supplemental oxygen:
15,000 to 18,000 feet ..........30 minutes or more
22,000 feet ...............................5 to 10 minutes
25,000 feet .................................3 to 5 minutes
28,000 feet............................2 1/2 to 3 minutes
30,000 feet .................................1 to 2 minutes
35,000 feet ............................30 to 60 seconds
40,000 feet ............................15 to 20 seconds
45,000 feet ..............................9 to 15 seconds



drdino 11th Mar 2014 22:53


Originally Posted by OPENDOOR (Post 8367748)
Looks strangely like a ship, from the on-screen scale, about 175' long.

Just saw it, definitely a ship with maybe a tender next to it.

john_curchod 11th Mar 2014 22:53

No information on the cargo on this forum whatsoever.

Very odd.

Other websites mentioning that the plane was loaded with too many lithium batteries.

Capt Scribble 11th Mar 2014 22:57

Simply turning a transponder off is not going to make a modern airliner disappear; there are too many systems sending information into the ether. On Airbus the loss of all electrics is regarded as impossible but some major power failures have happened. I'm not sure how the 777 is configured electrically, but a major electrical failure or fire in the E&E bay might cut all the aircraft communication systems and leave the crew poorly placed in the middle of the night.

overthewing 11th Mar 2014 22:59


Looks strangely like a ship, from the on-screen scale, about 175' long.
I managed not to notice the scale marker! Fine spotter I'd be.

Yes, I make it about 54m from point to blunt end. Bit to the left, which 'might' be a tail is about 20m. Close to the size of a 777-200ER?

If you squint...

File:B777FAMILYv1.0.png - Wikipedia, the free encyclopedia

andrasz 11th Mar 2014 22:59


If the altitude is reduced to a point where sufficient oxygen becomes available again, how soon would people start to regain conciousness
That depends on the amount of time spent in an oxygen deprived state, and the physiology of the actual person. Reinhold Meissner could climb Everest without supplementary oxygen, I would probably die in 15-20 minutes if spending any time above 8000m.

Losing consciousness is the body's protective mechanism, shutting down the massively oxygen-dependent brain and keeping up a slow circulation to maintain basic life functions - for a while. Beyond a certain time the process becomes an irreversible coma soon followed by cardiac arrest.

Assuming a 2000/3000 fpm descent, from 35k ft the aircraft would descend to an altitude that is capable of sustaining life in under 5 minutes, and in under 10 minutes to a level where full consciousness can be regained in a matter of minutes. However if there is any extended time spent above 8000m (that is more than max 5-10 minutes), then the answer is probably never.


Looks strangely like a ship...
Because it is a ship, nothing strange about it. There is a smaller vessel docked to its port side.

MrWooby 11th Mar 2014 23:04

Sounds to me like depressurisation, but you need to link depressurisation and transponder loss. This could be caused by structural failure taking out antennas, or electric supply loss on a common supply. Not sure about the 777 elec system but should have enough redundancy to ensure backups.

Following depressurisation, aircraft turned to return toward Malaysia and emergency descent. This is usually done on autopilot, so heading select and select alt of 10,000 or 14,000. Pilots would have donned oxy masks. However I wonder if there was a problem with the flight deck oxy supply. The company I worked for had a recent incident where the oxy supply to the flight deck was turned off. Not sure of the exact sequence but something like this. In doing the preflight oxy checks there was enough pressure in the oxy lines to enable oxy flow for the quick flick of the oxy test to ensure flow, at some stage during the flight the oxy pressure was found to be below minimum, it was then discovered that there was no oxy flow.

During emergency descent there would have been no flow if 100% oxy was selected, but if diluter demand air was selected they would have been breathing cabin air and would have passed out/died on descent. Aircraft would have descended to selected altitude. Level off and continued flying.
Looks like the track flown would have possibly taken them over Aceh, where terrain goes up to about 9000 feet in some areas, and then continued on in the Indian Ocean towards Diego Garcia until fuel exhaustion. Given endurance of say 7.5 Hours initially, aircraft would been flying about 5 hours at around 10,000 feet with speed brake out. Maybe at cruise speed around 300 kts.

Still many questions though. Pax oxy would have deployed, so pax should have been ok, but if only 15 mins oxy it would depend on the descent rate used in the descent. If pax alive over land then mobile phones would have probably been used. Cabin crew would have eventually entered the flight deck. If they found the crew deceased, maybe they tried to fly the aircraft and lost control.

Very Perplexing.

Speed of Sound 11th Mar 2014 23:12


Assuming a 2000/3000 fpm descent, from 35k ft the aircraft would descend to an altitude that is capable of sustaining life in under 5 minutes, and in under 10 minutes to a level where full consciousness can be regained in a matter of minutes. However if there is any extended time spent above 8000m (that is more than max 5-10 minutes), then the answer is probably never.
Thanks for that, although why my original post positing a hypoxia theory has vanished, I don't know.

Unlike the Helios tragedy where the aircraft kept flying in the 'death zone', flight MH370 started descending so at some point pasengers and crew would have begun to regain consciousness. Would the aircraft then have been too far from the mainland to make cell contact?

VH-XXX 11th Mar 2014 23:13

We need confirmation that the military radar tracked the aircraft in a perfectly straight line which would quite obviously indicate autopilot and could discount hijacking as hijackers would unlikely be flying in a straight line.

Sporky 11th Mar 2014 23:16

Ok, so IF (and a big if at the moment) it was a depressurization and for whatever reason the pilots were unable to keep/regain consciousness. When would ATC realise something was wrong and get some fast jets scrambled to check it out? Surely that would be a common sense approach.

wiggy 11th Mar 2014 23:17


Very Perplexing.
It is.


Sounds to me like depressurisation,
Possibly an option if we accept the idea that the aircraft was indeed the object detected on radar crossing the Malay peninsula.


but you need to link depressurisation and transponder loss. This could be caused by structural failure taking out antennas, or electric supply loss on a common supply

I wonder if there was a problem with the flight deck oxy supply
Perhaps it's worth asking a suitably qualified engineer for his/her opinion on the proximity (or not) of the crew oxygen bottle to significant electronic/electrical components :hmm::confused: . Could a problem with one cause a problem with the other?

Not speculatin', just askin'.....

tartare 11th Mar 2014 23:18

What's the MSA over the part of the Malaysian peninsula that they might have flown to get to the Malacca Straits?
I've looked on Google Earth but can't seem to find the elevation.
I wonder what altitude they were at tracking west?
Edited:
I see the RMAF are saying contact lost at 2:40am at FL29 near Pulau Perak.
I wonder if this is a de-pressurisation event over the Igari waypoint, an attempted turn onto a reciprocal track, some failure of flight deck 02 and hypoxia setting in before turnback complete... and a ghost flight heading out to sea westbound.
Why was mode C lost though - perhaps a partially hypoxic pilot selecting the wrong setting?
Still doesn't explain how some sort of jet-upset would happen to put the aircraft in the sea though.
Very strange indeed.

mickjoebill 11th Mar 2014 23:26


Earlier, someone pointed out that the waters surrounding the last known position are shallow, but the bottom sediments are often thick, loosely-consolidated pyroclastic deposits. Could these sediments 'absorb' a B777, travelling at speed?
Yes, raised in Post 1470.http://www.pprune.org/rumours-news/5...st8364903.html
The theory has not yet been debunked.
As a result of a near vertical dive imagine the small craters we have seen on land (flight 93 9/11) occurring in the muddy 20-40 meter sediment in shallow 30 meter waters of Malacca Straights.

Also references crashes in water where there was very little evidence of a fuel slick.(flight 990)

griffin one 11th Mar 2014 23:35

http://www.dca.gov.my/Division/Airwo...es/AN%2091.pdf

A possibility of inflight decompression

Calldepartures 11th Mar 2014 23:35

No digital communication from the aircraft following decompression? Also, o2 masks would explain the 'mumbled' radio transmission?

andrasz 11th Mar 2014 23:37


What's the MSA over the part of the Malaysian peninsula that they might have flown to get to the Malacca Straits?
Generally ~3000 feet, but there is a mountain range parallel to the coast east of George Town with ridges rising to 4000ft and the highest peak over 6000. Just to the north though there is a wide flat corridor inland where the entire peninsula may safely be crossed at 3000ft.

TURIN 11th Mar 2014 23:40

If I may...
 

Perhaps it's worth asking a suitably qualified engineer for his/her opinion on the proximity (or not) of the crew oxygen bottle to significant electronic/electrical components . Could a problem with one cause a problem with the other?
Crew 02 bottles are on the left side of the forward EE Bay tunnel. Just forward of the EE bay/Cabin access hatch.

There are significant electrical and electronic systems adjacent to the bottles but I'm pretty sure the ATC transponder boxes are far enough away not to be compromised immediatley should a bottle fail are a fire begin in that area.


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