Malaysian Airlines MH370 contact lost

[brika]

Turning from Where to Why

The Decompression theory appears to have a lot of support in this discussion:

Last night it emerged that the US aviation watchdog warned airlines six months ago of a problem with cracks in Boeing 777s that could lead to a mid-air break up and a catastrophic drop in cabin pressure.

The Federal Aviation Administration issued an alert in September last year giving airlines until April 9 to detect and correct cracking in the fuselage skin on Boeing 777s.

The FAA warned that failure to do so would leave the aircraft vulnerable to ‘a rapid decompression and loss of structural integrity’.

The organisation issued a final directive just two days before the Malaysia Airlines plane took off and said one airline had found a 16-in crack in the fuselage skin of a 14-year-old plane.

However, Boeing said that the FAA alert did not apply to the missing jet because it did not have the same antenna as the rest of the Boeing 777s.

And Malaysian Airlines insisted that the missing Boeing was airworthy before taking off, but declined to reveal whether it had been inspected for a known potential problem with the fuselage.

During a sudden drop in cabin pressure, the crew and passengers can become unconscious, leaving nobody in control of the aircraft.

mirror.co.uk - Mar 13, 2014 00:13

Perhaps 777 pilots can shed some light about how true this is.

The question is, if this is true, then, at around TOC is this the prime time for this disaster to happen?

[CogSim]

Because ETOPS 330 refers to the aircraft redundancy and resilience to cope with a significant failure and continue for fly for up to 330 minutes and land at a suitable airfield. It does not refer to your ability to find it.

In other words, you can shut down one engine and extend the range by upto 330 minutes?

[EcamSurprise]

put the transponder to standby, select 7700

My points on this statement:

1) My understanding is that this isn't required on the 777 (albeit maybe something from the past).

2) If I was in an emergency situation, my first action would not be to set the transponder. Aviate, Navigate & Communicate and all that good stuff. I would be on 02 and getting the aircraft going down. If I am by myself in the cockpit, then the 'flow' of bits like belts, pax 02, transposer and coms would be secondary to getting the aircraft established in a descent or under control.

3) Isn't the purpose of going to SBY to avoid accidentally setting one of the 'major' squawks. I.E 7700, 7500 or 7600.
If I was in an emergency situation, and I wanted to set 7700 anyway, why would I care about going to SBY first?

This just seems like an explanation which conveniently fits a scenario, but just doesn't come across as realistic.

IF all sorts is hitting the fan, to the extent that I FORGET to put my 02 Mask on as my very first action, then it is probably because I am attempting to control the the aircraft NOT faffing around with setting a squawk.

Lastly, with emergency descent perhaps being the exception, does everyone always set 7700 before talking to ATC? I'd find it more instinctive to be getting out some form of Mayday rather than playing with a squawk as my primary action or at the very least doing it at the same time. Even if it were a "Mayday Mayday Mayday, XXXX, Emergency Descent / Fire / Etc, STANDBY."

Just my thoughts.
I just don't buy it that someone would be playing with a transponder BEFORE descending the aircraft (if needed) as seen by the fact no change of course / altitude was detected and BEFORE going on 02. These are professional crews and I'd suggest 02 is a instinctive action.

[snakepit]

Well, if we do find this aircraft in the Indian ocean, that really only leaves one of two most likely scenarios:

1. Hi-jack

2. Foul play amongst one of the crew members. All it would take would be one crew member goes to the bathroom and the guy on the flight deck locks him out.

Hypoxia is still a possibility, but less so than 1 and 2 above. One needs a really big hole to get a decompression, and that would have been followed by a rapid descent, which didn't happen here. And we know the pressurization was functioning correctly since they cruised for awhile, so you can reasonably rule out a improperly set pressurization control

Mmm not true at all. One only needs a hole bigger than the outflow valves diameter and they are not usually that big. The alternative would be loss of pressurisation due to loss of incoming air from the ac packs 1&2 (can any 777 drivers confirm if they fail closed with power loss?) which could have conceivably happened when/if everything else failed rendering comms and txponder in-op.

[wiggy]

Whatever happened rendered the radios and transponder, as well as the crew O2 inop. Apparently it did not affect the A/P.

" Apparently it did not affect the A/P."

and there to my mind is the problem with the theory of the crew O2 bottle exploding and causing the accident - you've got to come up with a way of explaining how a fire/explosion can disable significant comms components in the MEC but seemingly leave the A/P and all it's associated systems intact enough to "fly" the aircraft, according to some theories for several hours. Credible? One for our engineering colleagues to answer I think.

And while I'm at it if anyone has to be informed yet again that on the 777 you do not turn the transponder to standby to change the code, you just punch in the code.....and touching the transponder at all, even a teeny bit, is not part of the Boeing Rapid Descent procedure I'll..........cry

[dmba]

Check your info

Boeing says Malaysia jet not subject to FAA inspection order | Reuters

"Boeing said it worked closely with the FAA to monitor the fleet for potential safety issues and take appropriate actions. But it said the 777-200ER Malaysia Airlines aircraft did not have that antenna installed and was not subject to the FAA order.

An FAA spokesman on Wednesday also cautioned against linking the directive, one of hundreds issued annually by the agency, to the disappearance of Malaysia Airlines flight MH370."

[Ian W]

Originally Posted by FMC

I, as I'm sure many members on this forum have been totally astounded how a modern commercial airliner such as 777-2 could simply disappear without trace. We understand the limitations of radar coverage and that of SSR. Moreover the mystery of a final ACARS message at 1:07 and nothing from RR is worrying at best.

It is appreciated that all these systems fulfil separate and important functions pertaining to flight and health but there appears to be an apparent omission in terms of off radar tracking. It certainly appears that the 777 in question was certified for ETOPS 330 operation but that certification excluded the requirement for real time SATCOM tracking when out of radar coverage. (In reality such tracking would be continuous from TO to Land but legally required when out of radar coverage.

Such technology is readily available and deployed by law enforcement agency's and private firms. 3 separate SATCOM units fitted to the nose, mid-section and tail that feed continuous data on the A/C track, altitude, speed and fix in 30 second intervals. The SATCOM units retain battery backup so can transmit for up to 10 hours after power loss. In this situation even if the 777 had exploded in midair there would be likely data transmitted to alert SAR response.

The fact that this aircraft has been missing for nearly six days is an indictment and embarrassment to the regulations, manufacture, and the various agencies that control civil aviation. This is not dissimilar to the Titanic board of inquiry that focused on the actions of the crew rather than the fact that Titanic was certified to sail with only 50% lifeboat capacity. My point is how can you certify to 330 if you have no ability to find it in an emergency?

The cost to implement such tracking is too often traded off against the probability of such an incident. The hull loss in this case will prove to be insignificant against the civil actions . The wider issue is the perceive loss of confidence in the ETOPS system by pax who may vote with their feet on long oceanic routes such as ANZ1 NZAA - KLAX on 777-3ER where nearly the entire flight is out of coverage.

My point is that this incident has wide and powerful implications for the airline industry. NOTE: before you say it ( yes it also pertains to 4 holers)

I fully agree with your points. The cost these days of a simple SATCOM device to ping its GPS position is peanuts even including the cost of certification (some are probably already certified).

Considering the astronomical cost of the current rescue that will almost certainly be borne by the insurance underwriters, it is not unlikely that insurers may withdraw insurance from any aircraft flying out of LOS of land unless it has some kind of standalone self-powered tamper proof SATCOM tracking. It doesn't matter what the beancounters in the airlines say, if their insurers will not cover them unless they are equipped; they will be equipped.

[tdracer]

Like how come RR and Boeing apparently have no data supporting the theory?

I wouldn't read too much into the lack of response from Boeing or RR. During an accident investigation, the manufactures are effectively under a gag order. All official communications are to come from the investigating agency.
While I've never known an investigating agency to blatantly lie, I have stewed quietly a few times when they couldn't be bothered to officially dismiss speculation or theories that we'd already disproved. All that being said, I think the idea that a US intelligence agency has access to some data that no one else does is plausible, perhaps even likely.

BTW, most modern FDR are capable of recording the max capable flight length, so there is little risk of the relevant data being overwritten unless the plane landed somewhere, refueled, and took off again (at this point I'm not sure I'd rule out much of anything).
The voice recorder is a different story though.

[LASJayhawk]

A/P FCS can get power from any buss like the pilots windshield heat.

Lot of other wis bang stuff gets load shed if major busses go off line.

But one does wonder if it was jacked, if they though the plane was fully fueled and would have more range than it did.

[albatross]

ETOPS

Someone asked a question about ETOPS.
Here is a short Boeing Video explaining it on the 777

New ETOPS rule extends 777's performance - YouTube

Just FYI ETOPS planning takes into account both failure of an engine and / or decompression along with other criteria such as loss of electrical power.

[Old Boeing Driver]

Wiggy

I agree with your comments about the transponder. Not sure a radar sweeps are fast enough to catch code changes anyway.

I'm not familiar where all the components are located in that electronics bay either.

There is always the possibility that the transponder just happened to fail...I know not probable.

[hamster3null]

Originally Posted by 1stspotter

I am wondering:
-how many unidentified plots on a radar were seen at the time MH370 went missing. Not much I guess.
-how much effort does it take to analyze the recording to learn alt, speed, heading of the plot
-how much other radars other than the Malaysia military could have picked up this plot on radar? Phuket?

so why does it take so much time to either confirm or rule out this unidentified plot was MH370?

The "unidentified target" was tracked by the radar at RMAF Butterworth. It crossed Malay Peninsula over Thai territory, well north of the border.

MH370 went silent roughly 215 NM from Butterworth. If it turned towards Phuket, its route would have passed over the middle of Gulf of Thailand, likely never getting closer than 150 NM to the radar. If whoever was piloting it knew about the military installation, they could have stayed at 200 NM all the way. It would stay at the edge of radar range and they'd only have an intermittent track that did not extend far enough back to connect to last known position of MH370.

As far as I can tell, Thailand does not have any active air force bases on the peninsula. At best the "target" could have been tracked by a couple of civilian ATCs there. Neither does Vietnam have any bases close enough to catch the moment MH370 turned off course.

[Chronus]

The aircraft has now been missing for six days. Assuming a mid air break up or break up on impact with water, there must have been some floating debris. It would be reasonable to expect that had this ocurred over the Malacca Narrows, bye now some floatsam would have reached the shores of these straights.
On the basis of a 5kt surface current, the floating debris would have travelled 720nm. It would be reasonable to expect that the SAR
co-ordination team would have taken this into consideration and concentrate their efforts taking into account the direction of surface water movements. However even if the point of break up is currently based on best guess, it is only a matter of time before some debris is washed up on someone`s shores. It is then that the real hard work of finding the location of the main wreckage will commence.

[ildarin]

First item in your immediate action checklist is put your oxygen mask on when there's an excessive cabin altitude warning.

Didn't work so well for Helios 522...

[glendalegoon]

ildarin

the helios crew did not recognize the BLARING HORN as cabin altitude warning, they thought it was the landing gear horn. same sound, different interval.

so they didn't put them on.

[hamster3null]

Originally Posted by shawk

Assuming that explosive decompression renders the heating system ineffective resulting in a cabin temperature of -20C, the crew and passengers will freeze to death in a few minutes. NIH lists survival time as 8.5 minutes at -20C.

I think you badly misread your source. 8.5 _minutes_ survival time does not even pass the smell test. At -20C in room-temperature clothing and without complicating factors (e.g. wind chill or rain), survival time is going to be on the order of 12 hours.

However, if you combine -20C temperature with hypoxia, things are going to turn badly much faster.

[WillowRun 6-3]

Correction by WSJ re data link

Correction: Satellite, Not Engine, Data Drove Investigators’ Suspicions on Malaysia Jet Flying Time
U.S. investigators suspect that Malaysia Airlines Flight 370 stayed in the air for up to four hours past the time it reached its last confirmed location, according to two people familiar with the details, raising the possibility that the plane could have flown on for hundreds of additional miles under conditions that remain murky.

The investigators believe the plane flew for a total of up to five hours, according to these people, based on analysis of signals sent by the Boeing 777's satellite-communication link designed to automatically transmit the status of some onboard systems to the ground.

Corrections & Amplifications: An earlier version of this article incorrectly said investigators based their suspicions on signals from monitoring systems embedded in the plane’s Rolls-Royce PLC engines and described that process.

[OPENDOOR]

the helios crew did not recognize the BLARING HORN as cabin altitude warning, they thought it was the landing gear horn. same sound, different interval.

They also ignored an engineers question;

"Can you confirm that the pressurization panel is set to AUTO?"

[SaturnV]

PPRuNe gets a favorable review in the NY Times.

http://www.nytimes.com/2014/03/13/wo...pgtype=article
________________________

The Wall Street Journal reporter who still stands by the core of his story, is one of the top, if not the top, aviation reporter at the Journal. Martha Raddatz, the defense reporter at ABC News, is very well connected with national security sources. IMO, the U.S. government is selectively leaking information.

Based on the Wall St. Journal reporter's accounts, the pinging lasted for four hours, at 30 minute intervals. So there was power and a functioning communication link during that interval. Depending on whether the U.S. can triangulate the location of each ping, that would give an approximate a location at the time of the last ping. That leaves up to a 30 minute flying distance from the point of the last ping.

According to the Journal reporter's radio interview, he mentioned several times that U.S. officials haven't ruled out the plane landing, or crash-landing on land.

[shawk]

I think you badly misread your source. 8.5 _minutes_ survival time does not even pass the smell test. At -20C in room-temperature clothing and without complicating factors (e.g. wind chill or rain), survival time is going to be on the order of 12 hours.

However, if you combine -20C temperature with hypoxia, things are going to turn badly much faster.

Yes, misread M for H in the abstract. The NIH number is 8.6 hours at -20C with two layers of loose clothing. Recovery time after several hours of -20C is fairly lengthly.