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Old 23rd Mar 2014, 17:28   #7561 (permalink)
 
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NAV mode to South Pole

Quote:
From waypoint IGREX to waypoint SPOLE (South Pole) how close would that put the aircraft to the final ping mentioned.
I was just about to post a reply which would answer that question with a map. The answer is that at 468kts after 5.5 hours it should be at about

-32.050, 97.68333

which is comfortably inside the last ping zone. If someone would care to provide better estimate for the endurance at IGREX and the forecast G/S I'll come back with an even more accurate position.

If, and it's a big if of course, there was some human control over the direction it took from the LKP, using NAV mode to a far-away waypoint would guarantee a straight line GC and therefore the greatest distance. What better than a pilot waypoint at 90S?
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Old 23rd Mar 2014, 17:31   #7562 (permalink)
 
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Quote:
As we have said before, the 777 won't stall. the FBW won't let it. And even if both engines fail, the RAT will provide power to autopilot and hydraulics. It will decend at a shallow angle, basically.
You mean, like an A330 ? I think Airbus was more or less, positive on that as well : the FBW will prevent a stall . We know that it's not entirely true .

I do not know the 777, but I think I remember someone stated that there is an alternate law mode, which does not guarantee AoA prot .
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Old 23rd Mar 2014, 17:45   #7563 (permalink)
 
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A fire doesn't necessarily means it will bring the aircraft down .... depends what's burning or smoldering? It could be producing enough toxic fumes or floating debris that it incapacitates everyone onboard. Remember the Helderberg when most (all?) the passengers died from smoke inhalation and toxic fumes from smoldering plastics. OK the tail came off eventually but possibly in MH730's case the fire just smouldered away or even burnt itself out? Transponder could be coincidental or tripped from a fire in FWD belly and close to the E&E compartment. Selecting HDG back toward base and FLCHG to e.g. FL100 would seem a normal action while actioning the fire / smoke checklist. If everyone was incapacitated in the meantime the aircraft would just continue at the selected altitude, heading and airspeed until it ran out of fuel at which point it would descend at the selected airspeed until it impacted the ocean and came apart.
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Old 23rd Mar 2014, 17:45   #7564 (permalink)
 
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Quote:
"According to the World Health Organization, the rate of suicide in Malaysia is close to the lowest on the planet; a tenth or so of rates in European countries."

But, is this due to Malaysia's measurement criteria? In a society where suicide is taboo (and not saying this applies), facts on the ground may be interpreted to uphold the norms. Durkheim spoke to this in his classic Suicide.
A fair point. WHO data is self-reported by country. But suicide is taboo to some extent in most countries, including the 150 or so reporting higher suicide rates than Malaysia. I doubt that a 10-1 or 20-1 ratio would be explained entirely by reporting bias.

Quote:
"The rate of suicide-by-loaded-aircraft amongst pilots is vanishingly low as well; statistically it's zero plus noise. Pilot suicide is a highly unlikely explanation for this incident. Unfortunately, so are all the other possible explanations. "
The commercial aircraft accident rate is also vanishingly small, too, isn't it? What % of this rate is due to pilot suicide?
I found 4 or 5 incidents of pilots deliberately flying aircraft with passengers into the ground over 30 years. I haven't tried to figure out how many fatal accidents there've been amongst airlines during the same period, but I know it's way, way more that that. Pilot suicide causes a tiny proportion of what is already a tiny number.

No one is arguing that pilot suicide is not a possible explanation for this event. But, when all the possible explanations are historically so improbable, I think it's a mistake to believe that one is less improbable than another. There's simply not enough data to come to any statistically meaningful conclusion. And it's really not fair to the two pilots in question, even though it is the conclusion that many people will draw if, as I believe is likely, the wreck site is never found.

There was a Northwest DC-6 that crashed into Lake Michigan in 1950 that still has not been found. The longer nothing is found on the surface, the harder it will be to locate the main wreckage.

If there's one lesson that must be taken from this incident, it is that the industry needs truly reliable tracking of commercial aircraft from takeoff to touchdown. The amount of bandwidth needed for such tracking is not large, especially if data was sent more often when the aircraft was not obviously in cruise (ie, constant heading, speed and altitude). Or, of course, such a system could be built on the existing ADS-B infrastructure. If something like that had been in place two weeks ago, the CVR and FDR would already be in the lab.

Disappearing aircraft and unsolved mysteries are very bad for business.
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Old 23rd Mar 2014, 17:46   #7565 (permalink)
 
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Quote:
I do not know the 777, but I think I remember someone stated that there is an alternate law mode, which does not guarantee AoA prot .
There is no AofA protection on the 777 in NORMAL law- it's quite different to the Airbus in that respect.

With the autopilot off, you can stall the aeroplane just like a Cessna. It will stop trimming near the stall, but if you keep pulling on the Control Column, you can stall it.

I didn't read the whole post this was in response to, but if the suggestion is that with the crew incapacitated, and the engines flamed out, the aircraft would continue on Autopilot with the RAT, that is entirely incorrect.

Firstly, if there is a power interruption on both main busses, the aircraft reverts to secondary control mode, and the Autopilot will not engage in that mode.

Once power is restored, primary mode and therefore autopilot capability can be restored, but only by pilot action.

HOWEVER- the RAT only provides a small amount of AC to a load-shed system- the Autopilot is NOT available on RAT power only.

In the event of a double flame-out, the APU automatically starts- but if the reason for the flameout is fuel exhaustion, the APU wouldn't start either.

If the aircraft flew on Autopilot until it's fuel was exhausted with unconscious pilots, it would have then entered a simple attitude holding mode, and descended wings level but otherwise uncontrolled.
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Old 23rd Mar 2014, 17:53   #7566 (permalink)
 
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Why are we talking about stall protection?

If the aircraft was "trimmed correctly" and then ran out of fuel it would still be....trimmed correctly. It would descend at the trimmed speed until it hit whatever. It wouldn't stall.
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Old 23rd Mar 2014, 17:54   #7567 (permalink)
 
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...

So SOPS if i understand you correctly, autopilot off, no protection from t7 fbw?
And if power is off (engines and apu off), ram can power adiru? If not, how is there autopilot available?
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Old 23rd Mar 2014, 17:55   #7568 (permalink)
 
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Fire in Cargo hold issue

Being ETOPS 180/192 minutes.... it would have a seriously good fire extinguisher for a class E fire suppression system which would be a mix of heavy duty halon and metered discharge means of ensuring prevention of smoke entering the passenger areas, ensuring sufficient time to give r/t calls and worst case a planned ditching...
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Old 23rd Mar 2014, 18:04   #7569 (permalink)
 
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AFAIK (not pilot; containership ops) you cannot "suppress" a runaway lithium ion battery with Halon.

Lithium-Ion Battery Hazards | content content from Fire Protection Engineering
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Old 23rd Mar 2014, 18:12   #7570 (permalink)
 
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Quote:
Originally Posted by Kooljack View Post
oldoberon:-



I disagree....the Chief of Air Force when asked by the media at that time, if the Air Force Radar Operator saw the air turn-back (i.e. in real-time), answered "No! We only saw a recording!"

pretty sure in a later post i stated he said confirmed by other data /sources. I was not meaning to say or imply they claimed they knew for 100% certain the next morning, although they did say contact lost over the Malacca straits. In the 1st instance that was contact of a return suspected to be 370, it was either the next or next but one they confirmed it was 370.

Do you believe it has never been confirmed?
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Old 23rd Mar 2014, 18:16   #7571 (permalink)
 
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I saw on a map that after the last contact it flew along/to waypoints. That doesn't make sense if a fire has been going on. Except if the FMC reverted to the second route loaded. Don't think its probable, but have to admit that I don't know the 777's FMC that well (737 pilot). To me it looks like someone knew what he was doing, at least navigation wise.
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Old 23rd Mar 2014, 18:25   #7572 (permalink)
 
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Glueball, of course you can make the left turn without the FMS. But previous and constant reporting over the past week stated that the left turn was programed into the FMS BEFORE the last voice transmission, the "Good night" transmission. That had tremendous implications that the intent to turn off course towards the west was established without the crew reporting anything out of the ordinary.

The left turn may now have been made in response to an emergency, not planned in advance. My larger point was that once again, what we thought we knew, what we thought was factual pieces of the jigsaw puzzle, turns out once again to apparently be false.
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Old 23rd Mar 2014, 18:26   #7573 (permalink)
 
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oldoberon

All recordings I have seen of radars are no less than the originals being replayed in a later time frame... quality or accuracy doesn't really suffer one bit... in fact one can slow it down pause etc...which might not be possible in real time so I think its a non issue..

Last edited by aviator1970; 23rd Mar 2014 at 18:30. Reason: ooops
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Old 23rd Mar 2014, 18:33   #7574 (permalink)
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oldoberon, given I posted a link to the recognised air picture which showed MH370 by military track number and marked with an arrow some 200nm WNW of Butterworth - yes.
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Old 23rd Mar 2014, 18:51   #7575 (permalink)
 
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Albert driver

Thanks for your clear and concise review about fire in the air.
What about about a slow incapacitation, by for example carbonmonoxide poisoning or other invisible products? (The garbled transmission, instinctively turning back not being able to iniate an emercengy descent could be compatable with such a sort of event.
Suggest we should all do some more proper brainstorming!
The WHAT IF and WHY BECAUSE type of thinking ,as the public would expect from professionals (leave the aliens where they belong )
My thoughts are with all the fine people from Malaysian Airlines who dearly miss their colleges
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Old 23rd Mar 2014, 18:52   #7576 (permalink)
 
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Dear Albert Driver,


Thank you so much.


I also have been in an aircraft we thought was on fire (fortunately it wasn't) but all the smoke and fumes convinced us at the time it was. Thank you for bringing a massive dose of common sense and experience to this debate - I totally agree with you! There is only one priority - GET IT ON THE GROUND ASAP - and at the same time, try to put it out.
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Old 23rd Mar 2014, 18:58   #7577 (permalink)
 
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Lord Spandex

If the aircraft was in trim with engines providing thrust, it would no longer be trimmed after engine failure.
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Old 23rd Mar 2014, 19:00   #7578 (permalink)
 
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@Pontius Navigator

Raised the point before re the Indian Navy base at Andaman and Nicobar Islands. You said "its for maritime" (didn't have time to get back).

"The Naval chief said that one of the primary functions of INS Baaz would be to provide information, based on ‘airborne’ maritime surveillance. “Maritime domain awareness is the key to effective and informed decision making in the maritime arena. Despite numerous advancements in the field of information gathering over sea, airborne surveillance, using aircraft and UAVs, remains invaluable,’’ he said".

Guess they "don't" have "Primary" then ???
That's how they "missed" them
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Old 23rd Mar 2014, 19:22   #7579 (permalink)
 
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Fire

The dissertation by Messrs. Engin Uzuncaova and Miguel A. Ayola, in their paper titled Boeing 777 Flight Control System, gives a useful overview of the FBW system used for the first time on a commercial airliner. Section 4 deals with Safety Analysis and states that the probability of a given failure condition is consistent with its severity, and that all failure combinations producing a catastrophe are extremely improbable.

The paper may be found at.

http://citeseerx.ist.psu.edu/viewdoc...=rep1&type=pdf

If we accept that the aircraft remained airborne for the whole period of its endurance, then it would be safe to assume that its electrical primary flight control system remained operative throughout the whole of this period. The crew were for reasons yet unknown were unable to divert it from its last assigned course and robotics became their master. Such a scenario does give rise to concerns over total reliance on automation and its implied dependence on electical power. In a similar vein I do recall there was, some years back, a short spell of trying to replace the old clicking cog mags with electronic ignition for light piston aircraft, it was soon abandoned.
What with first for FBW and all computer design, have we heard anything at all from the folks at Seattle. I just wondered whether they have made any comment at all.
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Old 23rd Mar 2014, 19:23   #7580 (permalink)
 
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Quote:
If the aircraft was in trim with engines providing thrust, it would no longer be trimmed after engine failure
The 777 uses an automatic speed trimmer, it would still continue to trim even after an engine failure. If hydraulics & electrics were still available after a double engine failure (Auto RAT deployment or high windmill speed) the system and the autopilot would remain engaged and try to maintain the assigned flight profile.
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