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

500N 19th Apr 2014 22:23


I think part of the reason it is "boring" is the JACC / Angus Houston and others are not prone or see any need to having unwarranted news conferences and have succeeded in damping down media speculation.

And apart from the basic info on the search each day, not much else.

That will of course all change when they find something !

PAXboy 20th Apr 2014 03:35

holdatcharlie asks the CVR question.

My question is this - How complete is that over-writing?
Question asked and answered much earlier in the thread. The answer (as I recall) was that analogye CVRs might have some trace left - although two hours of continues erase means probably not. However, the CVR unit on this aircraft was digital so the answer is Zero. (I sit to be corrected).

mm43 20th Apr 2014 05:41

Ocean Shield - SSS search
AMSA have recently defined the search area as within a circle of 10km radius centered on the 2nd ping detection. That area is defined by the White circle on the graphic below. The rectangular area on a major axis of 030/210 represents what previous AIS position reports indicate the area the Bluefin 21 AUV is working in. Each days positions are a different color, and the first position for today (20/04:03z) is shown in a Cerise color.

The Red stars represent when pings were acquired, and the sequence is numbered anticlockwise starting at the top. The White star is the position that the pings associated with the first ping were lost (LOS).


NOTE: Use Ctrl+ as many times as needed to enlarge the image, and Ctrl 0 will return the page size to normal.

joy ride 20th Apr 2014 07:36

The speculation about possible ADIRU software and windscreen problems being an issue in this case begs the question:

<< IF >> one or both of these had been a contributory factor, and assuming substantial recovery of wreckage, would the investigators have any chance of finding evidence of it? Particularly as a windscreen cracked by altitude/pressure changes might resemble one cracked on contact with water.

susier 20th Apr 2014 08:34

Just on the issue of windshield failure, there is an interesting digression on the manufacture of the above, in the TSB report pertaining to

17 OCTOBER 2002

where an arc resulting from overheating in the J5 terminal caused a small fire and the windshield to crack.

I won't link as I can't get it through moderation,

but anyway comms were not affected (obviously)

so if this were a contributing factor in the present case we would need to find a reason for lack of comms.

ETA (from the report)

'Boeing has undertaken a program to redesign the window terminal block to eliminate the screw connection. The new window blocks were scheduled to be incorporated into Boeing 777 aircraft, Line Number 471 (delivery date February 2004). The new design incorporates a locking pin/socket, which will address issues concerning loose or cross-threaded screws and inset ferrules. All Boeing 747, 757, 767 and 777 windows delivered thereafter, either on new aeroplanes or as spares, will have the new terminals installed. Boeing intends to deliver spares in kit form with the new wire end terminals included. The operator will have to remove the existing wire end terminal and splice in the new one when replacing windows on existing aircraft. The intent is to eliminate concerns with arcing at the window power terminals.

Boeing released a Fleet Team Digest article to B757 operators in May 2003, discussing terminal arcing and overheating. The article detailed actions to incorporate re-designed terminals into the affected cockpit windows.'

I'm not sure how relevant this might be, but it looks like there was no retro-fitting of the new system so as far as I can figure out, 9M-MRO will have had the original sort.

PPL Hobbyist 20th Apr 2014 09:05

CVR Question

As other people above have stated, when data on a PC or MAC has been deleted, the sectors on which the data resides is only flagged as deleted in the file allocation table. On the old 30 minute analogue tape CVR, it may still have been possible to recover over written audio, because the erasure head isn't always perfectly aligned with the recording head. or may not reset every magnetic fibre on the tape But on modern solid state digital CVR it is impossible because the memory modules only has 30 minutes or 2 hours of storage space depending on which model is on the plane, so the oldest data is constantly being over written by new data. The older data is completely erased.

I hope this helps.

barcino 20th Apr 2014 09:10

Finding more cabin recordings
The hope is on finding more cabin recordings based on passengers' personal devices being used during those dramatic final hours (i.e. smartphones, videocameras, etc.). Their memories might still be readable if sea water has not degraded its components seriously.

mixture 20th Apr 2014 09:44

Unfortunately the best testing can only test for what you are looking for.
Test scripts will only be based on what are considered possible scenarios.
Furthermore, the IT industry is now full of people who have been taught to program, not learnt to program.
One would like to think an operating system like windows would be fully tested, yet a host of bug-fixes are released every month, for years.
Yawn ! :ugh:

You've already been told above not to compare the generic IT industry to the niche part of the IT industry that deals with safety-critical systems.

Windows and such like are not subjected to the same formal design process that safety critical systems are. Thus of course you will get a greater number of bugs, some of which may cause substantial issues to the stability of the system. Bleeding edge generic IT projects these days can use agile development.....no such thing in safety critical systems.... in safety critical systems there is a traceability requirement for you to be able to show that a given line of source code fulfils given requirement specifications, the level of detail is truly excruciatingly tedious... but it all serves a very important purpose !

Sure there's always scope for issues, but the whole point of the almost obsessive-compulsive development methodology for safety critical systems is that failure or bugs won't kill anyone !

JamesGV 20th Apr 2014 13:28

On another note....

"Malaysian authorities are considering issuing death certificates for the missing passengers of MH370.
It's part of the plan to provide financial assistance to the families of passengers.
Deputy Foreign Minister Hamzah Zainudin, head of the next of kin committee, said no decision had been made on how much each family might receive".

Er ? The Montreal Convention.
Or is the carrier going to prove that they are totally "without fault".

Mike-Bracknell 20th Apr 2014 17:30

Originally Posted by Innaflap (Post 8442541)
Thanks PPL-Hobbyist

I used to do IC design when the Nimrod project was ongoing many years ago in So and GaAs and I haven't thought much about FETs in a long time! The media is almost certainly NAND memory.

What I was explaining is that depending on the technology used - FAT32 for example - that recording loads of the same noise will not take as much room (maybe 10%) as a chatty cockpit and that therefore voice files that have been tagged in the file table as deleted may not have been overwritten. If so, they may be recovered.

It's quite a mute point to be fair, because given the advances in technology if you're going to revisit the black box (and I think AF447 and MH370 prove there's at least a need for an updated spec, even if the cost-benefit analysis doesn't include retrofitting) then you'd include enough non-volatile storage per box to take many many hours of recording (along with other things such as an extendable, floating additional antenna).

lpatrick 20th Apr 2014 17:54

Oil slick
I think I have read every forum page but have heard no news of the analysis of the two oil slicks, did I miss it ?

Two to Tango 20th Apr 2014 17:59

Review the JACC media release recently. Confirmed oil not from a plane.

kwh 20th Apr 2014 18:24

It strikes me that these days (a duplicate copy of) the recorded flight data from both black boxes could in fact be stored in something physically tiny that was entirely self contained and external to the plane. There have been demands for a transponder to be carried that cannot be disabled by the crew, under duress or otherwise, so how about a little unit, externally mounted, on the tail cone perhaps, top of the fuselage or tip of the fin. No physical connection to aircraft power or systems, powered by an on board battery, which in turn is charged by a miniature RAM air turbine when the aircraft is moving. Include a transponder that will respond on demand to an internationally standardised IFF style interrogation challenge, or maybe regularly just pings co-ordinates to a satellite. If the same device also contains a non-volatile memory module which is written to from inside the plane via a bluetooth interface from the _real_ black boxes, with a facimile copy of both CVR & FDR data, all in a package designed to survive a water landing and end up on the surface amongst the debris field, if there is one, perhaps with the on-board satellite pinger previously mentioned still operating, then this situation literally can't happen again...

Kooljack 20th Apr 2014 18:43

joy ride:-

<< IF >> one or both of these had been a contributory factor, and assuming substantial recovery of wreckage, would the investigators have any chance of finding evidence of it? Particularly as a windscreen cracked by altitude/pressure changes might resemble one cracked on contact with water.
Without going into the microscopic details, I would reckon a fracture attributed to internal forces (failure with cabin pressurised) and one due to external forces (impact with water) will be pretty evident on close examination.

lucille 20th Apr 2014 19:27

I really hope I'm wrong but it's not looking good for finding the aircraft in that 10km radius zone. It seems more than 2/3rd has been searched to no avail.

The Malaysians have long labelled the investigation as being a criminal one. One can only assume, it wasn't a knee jerk reaction and that they have solid reason to do so.

Aviationexpert 20th Apr 2014 19:33

"Bluefin-21 has searched approximately 50 per cent of the focused underwater search area to date."
Search and recovery continues for Malaysian flight MH370

Howard Hughes 20th Apr 2014 23:12

Confirmed oil not from a plane.
The JACC were a little more non committal than that:

"Preliminary analysis of the sample collected by ADV Ocean Shield has confirmed that it is not aircraft engine oil or hydraulic fluid". (source: JACC website)

broadreach 20th Apr 2014 23:27

Howard Hughes,
Are you suggesting that the oil is not totally discounted as being from the aircraft and that it could be from cargo? E.g. an electrical transformer ruptured in the crash?

500N 20th Apr 2014 23:30

I notice in the JACC Press release that 11 aircraft are still being used
and this seems to be the case on a daily basis.

Not all the aircraft can drop buoys but are they still searching for debris, pings ????

Any comments ?

polarbreeze 21st Apr 2014 01:43

by Terminus: I would say no chance, as a boating person I have had 3 un scheduled swims with smartphones and their behaviour has been identical in salt water, they go off instantly and don't respond to anything,then get hot as they short circuit, the flash comes on then the device finally dies within 30 minutes.
Nevertheless, there is a good chance the non-volatile memory would retain its data which could potentially be recovered. If you'd broken your phone by going for a swim you wouldn't bother because the phone is not economically recoverable - but if it's a question of recovering data for a crash investigation that's another matter.

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