Noxious gas, from somewhere as yet unknown ?

The recent inflight arson attempt on the EY flight from MEL-AUH?

A similar attempt here with a different outcome?

Assuming Malaysian have an FOQA program couldn't they pull the QAR from previous flights the crew took (what is the history of the QAR?) and analyse any anomalies?

I have been looking at as many relevant maps as I can find and one thing has me interested....MH370 went "missing" from primary radar 1hr34min into the flight...If we then assume that it continued to go north-west for lets say 30+ minutes, so as to avoid turning back South over Indonesia (whom denies they tracked it on primary radar), then that is 2hrs of flying time gone out of the 7.3 it was allegedly flying for. That leaves it in the air for 5hrs30mins. If you then calculated a speed of 800kmh, the flying distance would be around 4500km. Looking at one map, the distance from Sultan Iskandarmuda Airport (Banda Aceh, ID) to Perth is 4700km....So how could the plane have ended up 1500-2500km south of Perth....
I may be looking at this all wrong :hmm:

All the scenarios at this point are just conjecture. If we look at AF447 for example, it was brought down by something we hadn't accounted for prior to the accident, this may very well be the same. All of the "it must have had human intervention" speculation, is based on absolutely no evidence, or at the very least unsubstantiated evidence. For the most part the investigating authorities cannot even get their story straight.

I can understand countries not wanting to give away classified information, but if there was one shred of evidence that the aircraft followed the Northern route, I am fairly sure it would be provided to the investigators (if not the source).

I don't suspect Australia, New Zealand, China and the US are conducting such a massive search on just a hunch, or even just based on the Immarsat 'pings' for that matter. Whether the information has come from JORN, or US and Chinese satellites we will probably never know, nor do we need to.

I cannot believe the number of so called 'aviation experts' on television pushing their outlandish theories. Time to hand back your ATPL's guys! ;)

Decompressing fire fighters
 

For all the genius so called pilots out there referring to the SOP's of fighting on board fires by decompressing or climbing heavy triple 7's to FL450 to starve them of oxygen.....

They have obviously drifted too far from the classrooms of their youth where they learned that the atmosphere consists of 21% oxygen ALL THE WAY UP!

Decompressing or climbing to FL680 will provide the fire with 21% of oxygen.

You guys should be checking out a career with CNN or the BBC

wild goose, the percentage of oxygen remains the same, what changes is the density which, putting it simply means that the molecules of oxygen are too far apart to allow effective respiration. If this were not the case there would be no need for people to have oxygen supplementation.

Dear Wombat
 

You are in danger of being percieved as missing the point entirely

The issue is fire fighting by oxygen starvation

not,

people fighting by oxygen starvation

The search is taking place is the most probable area according to available information.

We must, however, maintain a perspective on what may be found.

The objects seen by satelites are too large at around 70 feet long to be wreckage still floating 2 weeks after an aircraft crash and are most likely the inverted hulls of abandoned yachts known to be in the approximate area. These objects can float at or just below the surface for years or even decades. They can be observed by eye but being made of fibreglass they are invisible to search and rescue radars.

Other clusters of debris will be too small to be photographed by satelites but will be found by visual search by aircraft. A ship will then need to be tasked to examine and recover this debris. The problem here is that the oceans are cluttered with junk so the probability of any debris observed being related to the aircraft are fairly low and there will be false leads.

I am confident that if the search is in the right area something will be found but it will take time. Beware of raising false hopes until something is positively identified.

ULBs
 

A bit premature, but in the hope that this incident gets to this phase, here's some data on recovery of flight recorders and underwater locator beacons (ULBs).

The Wikipedia page on ULBs

https://en.wikipedia.org/wiki/Underwater_locator_beacon

links to this 1968 FAA report:

http://www.fire.tc.faa.gov/pdf/na68-7.pdf

"Background

Certain types of commercial transport aircraft are required by regulation to carry airborne flight data recorders for accident investigation purposes. A number of airborne recorders and their records were never located following a crash, especially after an aircraft crashed into water. The CAB requested the FAA to conduct a study for possible solutions to aid in locating the recorders and/or the recorded records from submerged aircraft. Following a crash in 1965 in which a flight recorderr and its record were lost in water and never recovered, the CAB formally requested the FAA to require commercial carriers to install acoustic-type locating beacons on all flight data recorders that are carried for crash investigation purposes."

The report talks about acoustic propagation through aluminum honeycomb fuselage structure, which may imply that was a consideration that drove the ULB acoustic frequency selection.

A set of slides describing at-sea recovery:

http://www.irs.uji.es/2nd-i-auv/pres...ert-Thomas.pdf

Slide 13 lists time to recover flight data recorders for a number of at-sea accidents.

Table 4 of the Metron report on AF447 has a more comprehensive summary of at-sea accident recoveries.

http://www.bea.aero/fr/enquetes/vol....h.analysis.pdf

Description of Table 4 in the Metron report:

"Table 4 below highlights data on 27 aircraft crashes at sea that were assembled by the BEA. Of the aircraft involved in these crashes, 25 were fitted with 2 ULBs while two had only one. The crashes involved 52 ULBs of which only 5 failed to function. This indicates a more than 90% survival rate which is higher than the 80% assumed for the underwater search analysis in section 4.3.1. The failures in the table include those of the ULBs onboard the South African Airways Flight SAA 295 which were likely to have been caused by an in-flight fire. With this in mind, the estimate of 90% survival rate for the ULBs may itself be low for a crash at sea that does not involve a fire."

While there appears to be some trend between depth and days to recover, there are exceptions, such as Air India 182, 23 June 1985, where the recorders were found 17 and 18 days later at a depth of 3250 meters.

For those cases with depths greater than a kilometer, half (4 of 8) had recorders recovered in less than 30 days. Of 27 cases in the table where at least one recorder was found, only 6 were found after more than 30 days, and only 3 after more than 90 days. The last 3 were all deeper than 1 km.

The design parameters of existing ULBs are close to the specs in the 1968 FAA report. One could argue that the 90% ULB reliability figure cited by Metron does not imply a need for any drastic changes to the ULB design (e.g., frequency).

The FAA appears to have been responsive to the BEA recommendation from AF447 to extend the battery life of ULBs. A 2012 notice of Revision B to TSO-C121:

Federal Register, Volume 77 Issue 43 (Monday, March 5, 2012)

This includes a number of interesting comments from industry.

Also being adopted in Europe:

http://www.easa.eu.int/rulemaking/do...0Issue%203.pdf

Plausible..

Pilots get the fire alarm, they turned back. Fire resulted in damage to electronics.

Fire also resulted in slow depressurization - starving the fire and incapacitating everyone on board

Which fire can depressurize ? LION batteries - fire than explosion causing depressurization.

Where were LION in cargo - forward or rear?

Supposedly the zigzag pattern after return is based on Malaysian primary radar - which cant be trusted - given Malaysia's past in sharing conflicting information..

But even if the crew is overcome by smoke, hypoxia, etc - then there's the question of how the plane stays in the air for seven hours with a fire burning in the hold.

Thanks jugofpropwash for your response. It’s a valid point and something I thought about while composing the post. I certainly don’t have any answers. There was only a small quantity and maybe, if they caught fire, the fire burned out. You would imagine other parts of the aircraft would have also caught, or other pieces of cargo, so it’s a long bow to draw. As we know strange things have happened in aviation, but that’s hardly an adequate answer either.
The last paragraph was purely my conjecture and I don’t think your point alters the thrust of scenario C – a major event. Time will tell and that will only be known when the orange boxes are found, but I think this scenario is far more plausible than the previous ones.
The other point is the heading. The turn back was in a general south west direction but the last known radar trace was roughly west. It’s the same as above, who knows what was in the FMC? Maybe another waypoint or discontinuity - but purely conjecture again.
I made a spelling mistake and edited this out. It’s been a long time since I’ve visited Pprune and in an excellent example of finger trouble think I deleted my post in the process. With apologies to those who read it in the mean time I’ve copied it here:

I guess I’m no different to a lot of us. Throughout this whole tragic episode my anger has been steadily rising. It’s not just the disinformation but the so called experts who’ve conjured up theories based on what is obviously minimal aviation experience, if any. I can’t begin to imagine how this cuts into those poor people who’ve suffered so much already.

MH370 took off and climbed to cruising level. The ACARS sent out its routine 30 minute report. Shortly after voice communication was lost along with the transponder. The aircraft made a turn and the next 30 minute ACARS report didn’t send. Up until this point the flight operated normally with communication routine. From this three theories have been put forward.

A: Someone from the Popular Front for the Liberation of Somewhere seized the aircraft. This someone had an in depth understanding of the Aircraft Communications Addressing and Reporting System, was a wiz with the Flight Director Autopilot System and had a deft hand when it came to the Flight Management Computer System.
Manipulating the controls, or forcing the pilots to, the hijacker is flush with a sense of satisfaction - this act of piracy will at last focus the world’s attention on the plight of the PFFTLOS.
There’s only one problem here, which should have been evident after a few days – and certainly after almost two weeks.
To add weight to this theory some expert from the Centre for Who Really Cares suggested the standard FIR handoff was a perfect position to turn the transponder off. As this was a sort of ‘No man’s land’ such a devious act would go unnoticed. We could talk about ATC coordination but suffice to say commercial RPT aircraft don’t fly in no man’s land.

B: A decent family man who’s been a loyal employee and worked his way up to check airman in MAS suddenly decides to make a radical political statement. Sure it was a Murdoch publication (so what would you expect?) but is someone in Australia who leans to Bill Shorten’s philosophy a radical extremist?
The FO is a young guy recently promoted from the 737 to the Tripler. His whole career ahead he will shortly marry.
They didn’t ask to be assigned together and if not acting in concert one would have to disable the other. The cockpit door is the most feasible theory but the question remains.
Here the scenario branches to; I’ve had enough - I can’t take it anymore – goodbye cruel world … in seven hours while in the mean time I sip on a brew or two from the Cameron Highlands.

I can’t believe some of these journalists, but then again pathetic journalism is nothing new. With the transponder out the aircraft disappeared off the radar. Radar’s been around since World War II. The transponder, as we know, identifies the radar blip. How do we know the aircraft flew back across Malaysia? It was tracked on radar. MH370 lost its ident but was the same physical object the radar beams bounced off seconds before.

Our simulator sessions are built on operational experience. Every time we do a sim check what happens? We take off and sometime after we have a problem. The problem is always serious enough so as not to continue the flight. We either return to our departure airport or an alternate. It’s a command decision but if serious enough the QRH is explicit – LAND AT THE NEAREST SUITABLE AIRPORT.
The radios are out, the transponder is out and contrary to first reports the ACARS ceased to function sometime between its standard 30 minute reports. It’s probably not a leap in faith to assume this happened when the other communication devices were lost. Who would continue on to Beijing? Through several FIRs, change altitude into metres, three different STARS assigned during the approach and numerous runway changes to add interest.
If you’ve flown a 737 around Malaysia and the region then you get very familiar with the airways and waypoints. Kuala Lumpur would be OK and Penang would be good. There are others as other pilots have pointed out. It would be a quick entry, if not the airway then a quick WMKK or WMKP. Entered into the FMCS and executed Lateral Nav will point the aircraft in the right direction and if not then Heading Select.
There were earlier reports of a climb to 1900’ above the service ceiling and then a dive to 23,000’. I haven’t heard any more of these and assume it went the same way as the erroneous ACARS report. If an event major enough to knock out the communications system then chances are there’ll be other damage. And so to what I believe is the most plausible theory.

C: The aircraft suffered a major problem. The pilots started working through the checklists and decided on an air return. Whatever the problem it was serious and some with greater aircraft engineering knowledge than me have suggested this led to a depressurisation. Whatever happened incapacitated the pilots. The aircraft flew on in LNAV or HDG SEL and at the MCP/VNAV altitude. If in LNAV and passing over the last waypoint the mode changed to HDG HOLD, as per its design. Returning in this direction was roughly South West and further south into the prevailing westerly winds. For a trip to Beijing there was approximately 8 hours endurance. Some used for climb and then traversing West Malaysia would mean, again approximately, 7 hours.

I didn’t make scenario C up. I added a bit from my local knowledge but it’s been out there. So why today do I open the paper and read the same old crap slandering two people, unable to defend themselves, who more than likely were busting their guts trying to save the aircraft and all on it? Some moron talked about ghosting, as if you could fly a 777 just below another aircraft through all the busy airways, some two-way, funnelling in and fanning out, level changes and the rest.

Now I will go out on a limb. It’s pure conjecture and I don’t pretend to have any expertise but it’s something I’m conscious of as I fly both passenger and freighter aircraft. Nearly every time I fly they’re there. In the cargo machines they can be half the load. In the pax aircraft they’re in the hold. I know they’re allowed and shipped in accordance with all the rules and regulations. But that was the case with the other types, before they brought down the UPS and Asiana 744Fs.
It was the one question I had and it wasn’t until today, buried deep in a secondary article, that this question was answered. A small quantity, all packed, shipped and loaded in accordance with the guidelines. But they were there.

@The Ancient Geek

You have it back to front, the size is 22M (72ft) wide and 13M (42ft) long.

http://resources3.news.com.au/images...8715-mh370.jpg

GPS through INMARSAT - still no tracking ability
 

I can understand the concern, but INMARSAT still uses normal SBAS transponders, like on other satellites. They transmit a pseudo-GPS signal on 1575.42Mhz via a "bent-pipe" transponder. The only thing the satellites receive is the SBAS signal from ground stations, which is then retransmitted via the transponder. Thus you cannot be tracked via this means.

Using a normal SBAS transponder makes sense - because this way you don't need a special receiver just for INMARSAT SBAS.

I will quit banging my head, but darn, I love that icon. :O

Re the graphic Flash8 posted with the red arcs and various possible flight paths shown -

While the area of highest probability to the south is logical, I feel the one in the north should be further back along the upper arc to the southeast. If the aircraft went north, it most likely did it via a convoluted route that avoided radar and may have been at low altitude. That would take additional time and spend additional fuel - meaning they wouldn't have gotten as far, correct?

wild goose - The percentage doesn't matter, the air is still far less dense so there will be less oxygen to feed the fire. If you are in a near vacuum and have 100 "air" molecules and 21 are oxygen, you probably don't have enough to feed combustion, though your ratio is still the same.

If I suspend my skepticism that MH370 was accurately tracked by primary through the advertised waypoints to a point North of Aceh, one could theorise the person(s) responsible for an intentional diversion dumped the cabin and waited for depletion of the pax O2 while they/he used the crew O2 supply, which while it runs longer, does eventually run out.

The cockpit masks do have to be put on properly, especially above 25,000'. An improperly fitted mask at 35,000' may not maintain useful consciousness.

Even at 12,500 without supplemental O2 you lose a bunch of IQ points -- and can get confused about which altimeter hand is 1000's and which is 100's :\

If I recall correctly, it was a couple days ago that officials said that the Captain had made a phone call just before departure, and that they were checking on it. Anyone heard any more on that? I would think that would be something that could be checked and presumably cleared pretty quickly.

I spy


The message was phoned through while the press conf was in progress and the dimension was misheard and now corrected.

Read ANY media report and it says this in all the ones I have read.

It is a minor point anyway in the scheme of things as he was only being informed,
The Chinese had already passed it to the Australians for action / acting upon.

Assets committed to searching the southern corridor:

http://i.imgur.com/nczeJj2.png