Malaysian Airlines MH370 contact lost

[Whiskey Mike Romeo]

In a BBC Radio 4 interview a couple of days ago, the commanding officer of HMS Echo said the search area had been localised to 10 miles by 5 miles. Assuming nautical miles, that is about 172km2.

In other words about the same size as the island of Jersey.

Quite a big area to lose a ULB on its own but small enough not to lose an entire aircraft, or most of its wreckage.

[cura]

My thoughts are that OS & Echo have pretty much localised the search area.
The 21 fish could not originally access the area due to depth constraints [ie <4500m].
They have over come this not through 'certification' but by trialing the fish deeper.

The best way of describing marine salvage is as -

"A science of vague assumptions based on debatable figures taken from inconclusive experiments and performed with instruments of problematic accuracy by persons of doubtful reliability and questionable mentality".

Let the experts do what they know best.

[Propduffer]

From the Sydney Morning Herald: "A survey by Malaysia's leading independent polling firm released earlier this week found that only 26 per cent of Malaysians believed the government was being transparent about MH370"

It would be reasonable to assume that those 26% don't actually believe that the Malaysian government is, or has been, forthcoming about events concerning MH370, but represent the hard core supporters of the government who also support the obfucation of MH370 information.

I hope the agreement between Australia and Malaysia regarding responsability for any recovered items would leave Austrailia as the recipiant of the FDR. Otherwise this whole SAR effort would be seen as pointless by 74% of Malaysians and many others (including the Chinese family members and myself.)

[roulishollandais]

@willowRun 6-3
Annex 12 applies in case of emergency and immédiate threat against a person.

[Two to Tango]

"A science of vague assumptions based on debatable figures taken from inconclusive experiments and performed with instruments of problematic accuracy by persons of doubtful reliability and questionable mentality".

Love the Quote! glad clinical trials are not run on those assumptions!

[JohnPerth]

It would be reasonable to assume that those 26% don't actually believe that the Malaysian government is, or has been, forthcoming about events concerning MH370, but represent the hard core supporters of the government who also support the obfucation of MH370 information.

Not being forthcoming with everything that curious people want to know is not the same thing as "obfuscation".

A classic example occurred in the past few days. A report emerged that the co-pilot's phone had connected to a tower in Malaysia. The journalist concerned characterised this as an attempt by the co-pilot to make a call, which is a different thing again. The Malaysia Transport Minister was asked if the report were true, and replied to the effect that he didn't know, but that in any case it would be a matter for the police, and that they would release such information if and when they saw fit. People on this forum then characterised that as a "denial" of the original report by the Malaysia Transport Minister, which it manifestly wasn't.

So, was there witholding of information here? Yes, by the Malaysia Police it seems, and there seems no reasonable grounds for criticising them for it. Was there obfuscation here? No. Was there confusion, speculation, general silliness? Yes, by a journalist and members of this forum...

[Glacier pilot]

Need to Know

CNN reports Malaysia states now aircraft climbed to 39000 over Malaysia after initial turn. That means the aircraft had to then descend to altitude close enough that tower could read an 'on' phone and then to 5000' (lost radar contact point) as previously stated by Malaysia. An unusual turn, an unusual climb, and an unusual descent is not exactly trying to stay off the radar (if someone had been looking).

[YYZjim]

ADIRU failure once again?

In 2005, a Malaysian Airlines B777-200 (9M-MRG) was on a flight from Perth to Kuala Lumpur when it experienced a failure of its navigation system. The airplane suddenly climbed to FL410, then dropped 4000 feet, then climbed 2000 feet. The pilots flew the airplane manually back to Perth. Australian authorities investigated the incident. They determined that the failure was in the "operating software of the air data inertial reference unit (ADIRU), a device that supplies acceleration figures to the aircraft's flight computer." The device was manufactured by Honeywell and contained the fourth version of the operating system. A review of the software showed that the error did exist on the first three versions of the software, but had been suppressed by other features of the software. These other features were removed during the transition from the third version to the fourth version.

The problem was serious enough for the FAA to issue an emergency airworthiness directive in August 2005 to all B777 operators to revert to version three of the operating system.

Note that the airplane lost on March 8, 2014, was 9M-MRO, apparently a sister ship.

[theAP]

YYZjim wrote,

Note that the airplane lost on March 8, 2014, was 9M-MRO, apparently a sister ship.

One of the most relevant post I've seen after a long time and most probably you have hit the nail imho.

[ampclamp]

YYZjim, re the sister ship ADIRU mishap. Investigation: 200503722 - In-flight upset; Boeing 777-200, 9M-MRG, 240 km NW Perth, WA

[kayej1188]

First off, terrific post. I'm struggling to fathom how this is the first time this incident has been mentioned. Maybe it isn't. It seems a number of parallels can be already drawn between the 2 flights. Could someone with more knowledge than me provide an answer as to whether or not a faulty ADIRU could correspond to ACARS + transponder being disabled?

[albatross]

Well considering it took place in 2005:
One would hope, being as there was an AD, that the present day software version would preclude a repeat, especially as the has not been another event in 9 years.

[harrryw]

@ampclamp
wxcept posibly as another comment on how useless the CVR is as it only had 5 minutes of relevent information because it had not been switched off on the ground.

[Lookleft]

The problem was serious enough for the FAA to issue an emergency airworthiness directive in August 2005 to all B777 operators to revert to version three of the operating system.

If Boeing thought that this incident was similar in nature and they had no answers then the 777 fleet would be grounded ( a situation which very nearly occurred after the 2005 incident). The fact that Boeing have not issued any AD's to operators (to my knowledge) suggests that they are not concerned that the aircraft has an inherent fault that could cause another 777 to disappear. The crew in the 2005 incident were able to override the automatics and recover the aircraft. For something similar to have occurred there would have to be another undetected software failure followed by a double incapacitation. Something which IMHO would be an order of magnitude beyond 10-9.

[Rightbase]

Mistakeology

It would be a very long bow to draw to link the 2 incidents in any way whatsoever.

Logic errors can remain undetected in programmed systems for a long time.

The protocol of flying on with 'redundant' units defective is such a 'program' that by definition does not create an accident but equally obviously does erode safety margins.

When it is the integrity of the 'intelligence' between pilot and aircraft that is jeopardised by such a program it then puts at risk the strategy of having a human in ultimate control.

Programmer humility deficiency might be a common root cause.

[mmurray]

A week to finish current search?

A report here that the current search will take 5-7 days to complete if the weather and the bluefin 21 holds up.

Malaysia Airlines MH370: Underwater search at 'very critical juncture', could be completed this week - ABC News (Australian Broadcasting Corporation)

[Ian W]

Originally Posted by Rightbase

Logic errors can remain undetected in programmed systems for a long time.

The protocol of flying on with 'redundant' units defective is such a 'program' that by definition does not create an accident but equally obviously does erode safety margins.

When it is the integrity of the 'intelligence' between pilot and aircraft that is jeopardised by such a program it then puts at risk the strategy of having a human in ultimate control.

Programmer humility deficiency might be a common root cause.

I know that there is a wish to find an answer but this is not it.

Logic errors can remain undetected - but this one was detected the quotes are from an investigation into an event that was caused and an AD was very publicly issued to return to the previous version of the software.

So now are you really suggesting that Honeywell, having been told of the fault in their software in unequivocal terms, forgot about it? Then over the 9 years since the incident that they have not updated the ADIRU software to fix the fault? To use a quote from tennis - You cannot be serious.

And of course this ADIRU software fault would need to also disconnect ACARS and switch off all three redundant VHF radios incapacitate the crew and then recover itself and fly the aircraft in uneventful cruise to the southern Indian Ocean.

Perhaps you would like to revisit your logic?

[Rightbase]

Mistakeology

Logic errors can remain undetected - but this one was detected

Your post kindly emphasised 'was' making the point that the logic error has been detected,

My point is the logic error of flying on with a tolerated defect in a system with the danger that a second defect could mislead the pilot is a critical vulnerability.

The vulnerability does not go away now that this one has been detected.

[mseyfang]

If Boeing thought that this incident was similar in nature and they had no answers then the 777 fleet would be grounded ( a situation which very nearly occurred after the 2005 incident). The fact that Boeing have not issued any AD's to operators (to my knowledge) suggests that they are not concerned that the aircraft has an inherent fault that could cause another 777 to disappear. The crew in the 2005 incident were able to override the automatics and recover the aircraft. For something similar to have occurred there would have to be another undetected software failure followed by a double incapacitation. Something which IMHO would be an order of magnitude beyond 10-9.

I tend to agree with this, but I have to admit that my first thought upon learning of this incident was ADIRU failure and/or an EE bay fire. The latter still explains everything known about the incident except for one important issue -- how the plane wound up headed in the general direction of Perth and the supposed track around Indonesia (still not entirely convinced of that as established fact given the source).

As for Boeing, in the absence of evidence that there is a fault in the aircraft (and theories aren't evidence), there are ample economic and liability/legal reasons to do nothing unless/until concrete evidence of a fault is discovered. Grounding the 777 fleet would be an enormous hardship for a number of carriers for which this aircraft type is the backbone of their long-haul intercontinental fleets, a group that includes the three legacy US carriers.

You don't ground a fleet of aircraft in the absence of specific evidence of a design problem. Prior groundings such as the Comet I (c. 1952), Lockheed Electra (c. 1959), the DC-10 (1979) and 787 were based on physical evidence of a potentially catastrophic problem with the aircraft. In this case, such physical evidence is, to date, completely lacking.

[Ian W]

Originally Posted by Rightbase

Your post kindly emphasised 'was' making the point that the logic error has been detected,

My point is the logic error of flying on with a tolerated defect in a system with the danger that a second defect could mislead the pilot is a critical vulnerability.

The vulnerability does not go away now that this one has been detected.

You have obviously not worked developing safety critical software.

The software in the ADIRU is not developed as if it were a video game or a university project: it is developed in line with RTCA DO-178 and ARINC 653. These are very strict standards with a lot of testing. However, despite all the testing some faults may/will be found and in most cases the system is designed that a fault in one module will be contained as part of a Failure Mode Effects Analysis. It would appear that a fault was successfully contained and then unmasked when another module was updated.

Now at that stage with safety critical software the FAA and Honeywell reverted back to the previous version - which had worked without a problem using an AD. Honeywell would then have had a 'MUST FIX' top emergency software fix to carry out. In many organizations that means NO new software version can be delivered unless that fault is fixed.

Your attitude that they would have left it on the old version as that was 'good enough' is just not the way the industry works.

I would expect that the fault was fixed within days and then after recertification testing with the FAA and Boeing, Honeywell would have delivered a new ADIRU software build with all known bugs including this one fixed. The longest part of that effort will have been testing, and the particular issue that caused the ADIRU to fail would be included in the new acceptance test suite. Almost certainly there would also have been some effort to defend against ADIRU faults in the FMC software as part of the FMEA work.

High availability safety critical software development demands getting things right, designing systems to be resilient to subsystem faults, and rapid resolution of any faults found.