Malaysian Airlines MH370 contact lost

[Downwind Lander]

Today, it is precisely 13 years since a nutbag islamist on board United 93 switched off his transponder and caused problems for ATC tracking staff.

Earlier this year, the same appears to have happened to MH370.

I have heard various excuses varying between "far fetched" and "daft" for why this switch should not be capable of being disabled from the flight deck. Will the regulators ever wake up?

If they do, they could also consider why FDR and CVR batteries are so inadequate and why these should not operate in passive transponder mode.

[wiggy]

Smoke Removal and various versions of Cabin and/or flight deck Smoke and Fire drills often call at some point for electrical power to be removed from items (either by a switch or by disconnecting busbars) in order to try isolate the source of the problem.

Do you consider such drills " "far fetched" or "daft"?

[Downwind Lander]

wiggy says: "Smoke Removal and various versions of Cabin and/or flight deck Smoke and Fire drills often call at some point for electrical power to be removed from items (either by a switch or by disconnecting busbars) in order to try isolate the source of the problem.

Do you consider such drills 'far fetched' or 'daft'? "


So far, we have lost two aircraft and their passengers. That is a high price to pay. We may have lost them anyway. Certainly, this crucial circuit should not interfere with drills; with good design, it does not need to.

[formulaben]

Today, it is precisely 13 years since a nutbag islamist on board United 93 switched off his transponder and caused problems for ATC tracking staff.

Earlier this year, the same appears to have happened to MH370.

I have heard various excuses varying between "far fetched" and "daft" for why this switch should not be capable of being disabled from the flight deck. Will the regulators ever wake up?

If they do, they could also consider why FDR and CVR batteries are so inadequate and why these should not operate in passive transponder mode.

Precisely how would souls have been saved if either UA93 or MH370 would have continued to squawk during its doomed flight?

[Downwind Lander]

formulaban says:
"Precisely how would souls have been saved if either UA93 or MH370 would have continued to squawk during its doomed flight?"


ATC couldn't find UA93. The F-16s did not know where to go. As for MH370, the signals would have been of immense value, if only for investigative purposes.

[Ian W]

Originally Posted by formulaben

Precisely how would souls have been saved if either UA93 or MH370 would have continued to squawk during its doomed flight?

UA93 was in an area (sort box) that was only secondary radar so disappeared. Continual tracking would have enabled some kind of fighter response - whether that would have saved anyone nobody can know.

MH370 appears to have deliberately stopped squawk. Had it continued there would not have been a wasted effort searching the South China Sea for the aircraft and it would have been apparent that it had flown across the straits of Malacca and around the northern tip of Indonesia. Again, there is no way that anyone can know whether that would have led to people being saved, but it certainly would have reduced fruitless searches and some 'dark' satellites may well have tracked it to its final demise allowing recovery efforts to commence in the right place before the barely useful FDR/CVR locator batteries died. Again saving huge amounts of time and effort.

Finally, knowing that whatever is done in the cockpit the aircraft will be continually tracked _may_ act as a deterrent for certain planned hijacks in the future.

[formulaben]

So we have established it will help find wreckage or aid in an intercept (shootdown) of a hijack in progress. Time and money might be saved in S&R ops, but zero souls saved with a transponder that is unable to turn off. Perhaps that is why regulators have not "woken up"?

[susier]

It's not just S&R, it's a massive issue across the board. If you can't find the AC you don't have answers and it affects just about every aspect of the industry from SLF confidence to technical R&D. Thought that was obvious.

[mixture]

So far, we have lost two aircraft and their passengers. That is a high price to pay. We may have lost them anyway. Certainly, this crucial circuit should not interfere with drills; with good design, it does not need to.

Its quite frankly ludicrous that you say its perfectly acceptable to make it impossible to turn off a piece of electrical equipment during Smoke and Fire drills.

All you are doing is replacing one major problem (the tracking question), with another major problem (sending those on board to their early demise through smoke inhalation and/or fire).

Quite frankly, I don't give a damn how good you think your circuit design skills are.....there will always be instances where the brown stuff hits the fan and unforeseen (or impossible to avoid) scenarios lead to the need to turn a piece of equipment off.

[slats11]

In some ways risk is like an air filled balloon. Early on, it's pretty easy to reduce risk (use your hands to squeeze the ballon to reduce its size). Over time it gets harder to reduce the total risk further. Squeezing the balloon in one dimension results in it bulging out in a different direction.

Sometimes this increased risk elsewhere is anticipated. Sometimes it is not - until it happens. It becomes a trade off, and you can never get it down to zero.

Mh370 may have come about partly through our efforts to mitigate 9/11.

So this question is a balance of risks. On balance, I wonder if the risk of being able to turn a transponder off is greater than the risk of not being able to do so.

I accept that a functioning transponder may not have saved lives, either here or 9/11. We will never know for sure.

But we would know what had happened in real time. With 9/11 it might have permitted the shooting down of UA93 had passengers not taken things into their own hands. A hell of a decision, but what would you have authorities do if it was headed towards a major population centre. We would likely have the recorders for MH370. And the sure knowledge you couldn't disappear may act as a deterrent.

As the world moves into a period of higher risk, the (acknowledged) risk of not being able to turn off an electrical item may actually now be the smaller risk.

[mixture]

I accept that a functioning transponder may not have saved lives, either here or 9/11. We will never know for sure.

It would not have saved lives, that's obvious based on the fact that its an aircraft you are talking about.

Once the aircraft has been commandeered by miscreants, there is always going to be bugger all you can do about it until the aircraft reaches the ground in one form or another (i.e. whether they crash it or a government blows it out of the sky.... the result in terms of the lives of those on board is the same).

I suspect rather than creating stupid fire hazards by hiding away equipment, you will find the more obvious solution to MH370 is staring you in the face .... improved profiling and psychological monitoring of flightcrew.

[slats11]

It would not have saved lives, that's obvious based on the fact that its an aircraft you are talking about.

Well it could have saved lives if it had been a sufficient deterrent to prevent the "hijacking" in the first place. And being able to track a plane could perhaps help to save lives on the ground. Can we agree that we would prefer to track a hijacked plane than not track it?

improved profiling and psychological monitoring of flightcrew.

It would be hard to think of a less effective measure than this. Psychologically profiling is unable to identify someone about to commit such an atrocity. No psychologist believes this is possible.

Due to the number of incidents, the best data probably comes from looking at mass murderers. Yes in retrospect people will often come out and say the offender was odd or unusual in some way, or had recently suffered a relationship breakdown. But that is very different to prospectively identifying someone in time to prevent an atrocity.

There are certainly some "risk factors" e.g. male gender, feeling isolated, being a bit aloof or awkward among others, recent marriage breakdown, financial problems etc. However these risk factors are so common they define a significant proportion of the population. Does anyone know a male pilot with marriage difficulties?

The risk factors have high sensitivity (i.e. some of these factors will be present in most offenders), but appalling specificity (in that the overwhelming majority of people with these risk factors will not offend). So we can use these risk factors to predict that the next offender will likely be a male with some interpersonal difficulties, but we can't predict the identity of the next offender. They are useful at a population level, but completely useless at an individual level.

This article is a few years old, but is still true today
Dark Matter: The Psychology Of Mass Murder

"Terrorism" used to be about getting a gun onto a plane and issuing demands to release prisoners etc. 9/11 changed that - it was about getting a pilot onto a plane, forcing entry to the deck and taking control. It has probably changed again with MH370.

I would certainly take my chances with being unable to isolate an electrical system than with psychological screening.

[Downwind Lander]

Slats11 says:

"I would certainly take my chances with being unable to isolate an electrical system ...".

I suspect, but don't know, that the transponder circuitry itself is remote. All that is local is the line and the switch. And, in my view, even they don't need to exist.

But nobody is talking about the CVR and FDR batteries. Surely none of my detractors think that these batteries are sufficient? I wonder if a power source can be devised using seawater as an electrolyte and dissimilar metals as electrodes.

[Ian W]

Originally Posted by Downwind Lander

Slats11 says:
But nobody is talking about the CVR and FDR batteries. Surely none of my detractors think that these batteries are sufficient? I wonder if a power source can be devised using seawater as an electrolyte and dissimilar metals as electrodes.

There was a significant discussion on CVR/DFDR batteries several eons ago on this thread. Not only that but on the choice of frequency, the lack of modulation of the ping with an aircraft ID or last GPS position, and power increases by reduction of the number of pings or by using transponder techniques.

It seems that the CVR/DFDR spec for locator beacons was for finding the recorders in a river or lake. The expansion of transoceanic flight passed by the people setting the requirements until AF447. Now they are belatedly increasing the battery capacity but other 'bright ideas' have not been taken up.

[Vinnie Boombatz]

ATSB Updates

Some new material posted by ATSB.

MH370

3D map of sea floor (2.2 MB) in search area:

http://www.atsb.gov.au/media/5092636...or_terrain.jpg

Depth in primary search area roughly 2 to 3 km, some deeper, some shallower.

[Eyrie]

One good reason for having a transponder that can be turned off from the cockpit is it if develops a fault and starts giving bad data to ATC.
AFAIK large airliners have two transponders in case one fails.

[Vinnie Boombatz]

Sep 9 update by Duncan Steel, Michael Exner, Tim Farrar et al:

MH370 Search Area Recommendation | Duncan Steel

https://dl.dropboxusercontent.com/u/...09-09_Rev1.pdf

Their best estimate of position at the 00:11 ping is 37.5 S, 89.2 E, very far removed from the ATSB search areas. Their recommendation would further imply a need for another several months of bathymetric survey.

On the other hand, John Zweck, Australian Ph.D. in mathematics does an independent calculation that aligns very well with the ATSB search area. His August update:

http://www.utdallas.edu/~zweck/MH370AugustReport.pdf

(Note: to convert km/hr to knots, divide by 1.852)

Zweck's best estimate of position at 00:11 ping using great circle model is 989 E, 27:64 S and using small circle model is 99:16 E, 27:28 S.

These don't account for glide after fuel exhaustion, so are very close to the center of the ATSB Priority search area.

Sep 10 link to Zweck's latest spreadsheet:

Aqqa on MH370

[Dont Hang Up]

I would certainly take my chances with being unable to isolate an electrical system

Which rather implies that you consider the risk of hijack on any given flight is more severe than the risk of electrical fire on board. I am not sure that would stand up to statistical scrutiny, probably by a factor of several thousand - even if the "no-off" transponder was a sure fire deterrent of hijack, which clearly it is not.

The mystery of MH370 is frustrating, but perhaps it is better to just swallow that frustration than fit an additional fire hazard in every commercial aircraft just in case it happens again.

As for psychological profiling, I am similarly sceptical about its effectiveness. But at least it is directly addressing prevention. The transponder issue is just helping us find the wreckage afterwards.

[PrivtPilotRadarTech]

Quote:
"Which rather implies that you consider the risk of hijack on any given flight is more severe than the risk of electrical fire on board. I am not sure that would stand up to statistical scrutiny, probably by a factor of several thousand - even if the "no-off" transponder was a sure fire deterrent of hijack, which clearly it is not."

Electronics is my area of expertise. First, low-power devices pose little fire risk. Second, there are hundreds of such devices on any given commercial jet- phones, laptops, etc- which the pilot cannot turn off. Adding one more won't make any difference.
Third, the technology is readily available and cheap. Something like a $150 SPOT beacon could report periodically, somewhat like a transponder. Smart people can work out the details and address legitimate concerns, but it's nuts not to track every airliner in the post- 9/11 era.

[Dont Hang Up]

Electronics is my area of expertise.

OK

First, low-power devices pose little fire risk.

The two Mode S transponders on a typical commercial airliner have a 500W plus transmit power!

Something like a $150 SPOT beacon could report periodically, somewhat like a transponder.

...so yet another piece of equipment on board. Can we just have a reality check here. There are already means of satellite tracking aircraft. It is just that on this one occasion that means was disabled - possibly deliberately, but we do not know for sure, and if it was disabled by electrical fire then this whole argument gets a bit ironic..

When CVR and FDR became mandatory this fulfilled a clear purpose: Post accident analysis to find means to prevent recurrence. However, adding ever more kit to report on ever more rare events just does not make sense to me.

We have to assess risks and mitigation properly before we add our quick fixes.

but it's nuts not to track every airliner in the post- 9/11 era.

Maybe I am nuts, but to me that seems to have been an excuse for adding extra layers of surveillance on just about everything and everyone. Even since that fateful day the risk from terrorism remains one of the tiniest risks an individual (even an airline pilot) will face in their daily life.