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Old 23rd Mar 2014, 18:19   #7541 (permalink)
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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.
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Old 23rd Mar 2014, 18:21   #7542 (permalink)
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Originally Posted by aviator1970 View Post
but RNAV means of terrestrial aids such as VOR DME will be used to more accurately position fix.
Which of course are limited to line of sight or roughly around 200 miles maximum. They also need operator input.

Last edited by Pontius Navigator; 23rd Mar 2014 at 19:03.
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Old 23rd Mar 2014, 18:23   #7543 (permalink)
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Just when you thought you'd finally drowned it, the issue of fire just keeps on springing up

So, for the benefit of non-pilots, let's talk about fire - from the point of view of this former 747-400 commander's experience.

Cargo Fire:
The T7 is fully equipped with cargo fire detection and suppression for some 30 minutes or so (T7 drivers will fill in the number).
I've had a cargo fire warning. It rattles your eyeballs and soaks you with adrenaline. You can't ignore it. You do the drill and fire the bottles, put out a Mayday, ask for radar assistance, point the aircraft at a runway and get going down (in whichever order is appropriate, or all at once). It's just like we regularly practice in the sim. Mine turned out to be a false warning - but still......
In the position of MH370 there would have been radar assistance, a choice of runways within the fire suppression time available supported by the familiarity of being near base.
There is no way a cargo fire caused the loss of MH370, with no Mayday call, plenty of assistance available and time in hand to land.

Wheel bay fire:
If there had been a fire in the wheel bay the crew would have known about it from the sensors immediately after take-off. They would not have got as far as leaving departure control without asking for a return to land. Let's put this one to bed.

Flight-deck fire:
If a fire occurs behind a flight-deck instrument panel you know about it immediately. From experience, you smell it and see the smoke long before it takes hold. This type of fire can be difficult to deal with but there are extinguishers and axes/jemmies to hand. Oxygen masks on, Mayday, descent and diversion by the handling pilot while the other crew member(s) deal with the problem, is the response. There may be loss of some services depending on which panel is affected but at the end of the day the handling pilot can just take out the autopilot and fly the aeroplane, for which radar assistance resulting from that Mayday call is most helpful. Provided the fire is controlled to keep the smoke down and a runway is within reach there is no reason why a safe landing should not result.
For the reasons given for Cargo fire, a flight-deck fire did not cause the loss of MH370.

Electrics Compartment fire:
I've experienced smoke in the electrics bay. The compartment has a high airflow for cooling purposes and we smelt it on the flight-deck immediately, before there was any visible smoke. A quick check of the flight-deck panels, a zoom out into the cabin to check for smoke. a call to the galley-slaves to check the galley equipment - and it became immediately apparent where it must be coming from. In my case the appropriate CBs tripped themselves and the problem solved itself but in a more severe case it would be little different to the flight-deck fire case as above, except for some small extra difficulty of access (although our engineer was down there like a mole in a hole).
For the same reasons an electrics bay fire did not cause the loss of MH370.

Cabin fire:
Causes can be many. I've experienced a small furnishings fire (caused by an illegal cigarette we think). Smoke identified the source long before fire took hold. The cabin crew were on to it straight away with more extinguishers carried to the scene than I thought existed on the aircraft!
I've also had an electrical cabin fire. That was more difficult to locate as the smoke was distributed by the recirc fans. It eventually scorched a side panel revealing itself and the cabin crew pounced upon it relishing, it seemed, the opportunity to use the axe to get to it! We were already on approach by then but I'm confident that had we been in the middle of the Atlantic we would have dealt with it just as safely.

Incendiary devices:
In the cargo hold it becomes just another cargo fire, unless it is also an explosive device, in which case case the aircraft either breaks up (which we know MH370 did not do initially) or it may cause a decompression as well as a fire. In the latter case the fire suppression systems would likely be rendered inoperative or ineffective - clearly a more critical case. But pilots practice loss of cabin pressurisation drills frequently. If this had happened and the aircraft survived the initial explosion and the emergency descent they were still within range of a runway and they would have declared an emergency. Pilots do not forget to put on oxygen masks. In this case you just need a closer runway - and MH370 had one.
In the cabin, it's just a bigger fire. Trust me, the cabin crew will be there with extinguishers within seconds. There are more than enough extinguishers around.
If it is also an explosive device then we are back to the cargo hold explosion situation as above. The cabin crew may be stunned and react slowly but the flight crew will descend the aircraft and declare an emergency. There is no evidence that happened in this case.

The point I am making is that all fires on aircraft can be dealt with by the crew. There is ample equipment on board and sufficient crew members trained to use it. The problem is not in dealing with the initial fire but whether there is a runway close enough to use while the fire remains suppressed. That is what causes hull losses due to fire in flight. In the case of MH370 there was a choice of places to go and a radar controller to talk to and get help from.
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Old 23rd Mar 2014, 18:27   #7544 (permalink)
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Thanks for the answer. I'm not familiar with the T7 protection laws and only have basic knowledge of Airbus ones. So stall protection is not lost even if engines are not running on T7.

Could the 'shallow' descent also mean survivable aircraft attitude and speed upon reaching sea level?
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Old 23rd Mar 2014, 18:28   #7545 (permalink)
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NAV mode to South Pole

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, 18:31   #7546 (permalink)
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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, 18:45   #7547 (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, 18:45   #7548 (permalink)
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"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.

"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, 18:46   #7549 (permalink)
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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, 18:53   #7550 (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, 18:54   #7551 (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, 18:55   #7552 (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, 19:04   #7553 (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, 19:12   #7554 (permalink)
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Originally Posted by Kooljack View Post

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, 19:16   #7555 (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, 19:25   #7556 (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, 19:26   #7557 (permalink)
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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 19:30. Reason: ooops
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Old 23rd Mar 2014, 19:33   #7558 (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, 19:51   #7559 (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, 19:52   #7560 (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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