Malaysian Airlines MH370 contact lost
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If both pilots became disabled, and unable to respond to calls from the cabin crew, would the cabin crew have any means to open the inviolate cockpit door?
Reason I ask is perhaps one pilot disabled the other to carry out some plot, but before that pilot either died or became unconscious, he retaliated in some fashion to disable the other pilot.
Now in this scenario, we have two disabled or dead pilots behind a locked cockpit door, the plane on autopilot until it flames out 8 hours later.
Reason I ask is perhaps one pilot disabled the other to carry out some plot, but before that pilot either died or became unconscious, he retaliated in some fashion to disable the other pilot.
Now in this scenario, we have two disabled or dead pilots behind a locked cockpit door, the plane on autopilot until it flames out 8 hours later.
There seems to be an assumption that the aircraft couldn't remain airborne for hours without either a working autopilot or human input. This assumption is almost certainly wrong.
Water impact
Have the boys in the 777 simulator shut down both engines and seen what the aircraft does until impact?
Airspeed, rate of descent, systems failures, autopilot disconnects ect.
You would have to do a number of scenarios, both engines shut down at the same time and one engine fails then the other, various autopilot setups IAS, Alt, Heading, Nav ect.
Airspeed, rate of descent, systems failures, autopilot disconnects ect.
You would have to do a number of scenarios, both engines shut down at the same time and one engine fails then the other, various autopilot setups IAS, Alt, Heading, Nav ect.
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The graphic in post #5965 has further been updated with the positions of the LKP at IGARI and a possible PSR position at 1822z, that are interlinked to the possible backtrack position west of Banda Aceh.
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If both pilots became disabled, and unable to respond to calls from the cabin crew, would the cabin crew have any means to open the inviolate cockpit door?
Reason I ask is perhaps one pilot disabled the other to carry out some plot, but before that pilot either died or became unconscious, he retaliated in some fashion to disable the other pilot.
Now in this scenario, we have two disabled or dead pilots behind a locked cockpit door, the plane on autopilot until it flames out 8 hours later.
Reason I ask is perhaps one pilot disabled the other to carry out some plot, but before that pilot either died or became unconscious, he retaliated in some fashion to disable the other pilot.
Now in this scenario, we have two disabled or dead pilots behind a locked cockpit door, the plane on autopilot until it flames out 8 hours later.
EDIT:
To "Heli-phile" (who was concerned about my post but won't take PM's)
This information is just common sense. There would have to be a way for the cabin crew to access the flight deck in case of an emergency. And there would also have to be a way for the pilots to keep people out if needed. This basic information is already available online for anyone who cares to look for it.
This procedure varies with each airline and of course I would never describe the exact procedure at my airline.
SKYbrary - Flight Deck Security
Emergency Flight Deck Access. Most security systems have the facility for emergency access to the flight deck; such systems have safeguards built in to allow the flight crew to prevent access, for example by building in delays to the door opening such that the flight crew, if not incapcitated, can overide the lock release.
Last edited by Lost in Saigon; 23rd Mar 2014 at 03:22.
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If both pilots became disabled, and unable to respond to calls from the cabin crew, would the cabin crew have any means to open the inviolate cockpit door?
IOW The cabin crew can try all day to open the door from the outside, but a conscious pilot in the flightdeck can prevent this each and every time.
Robert,
The 777 is FBW. It does not require trimming for power changes, only for speed changes. Once its trimmed, and autothrottles are looking after the speed its very stable, and flies very nicely hands free.
There are plenty of incidents where aircraft have continued on autopilot after the crew have become incapacitated.
If in the cruise and the fuel starvation point is reached, one engine could fail before the other. In this case, autothrust (autothrottle? been a while since I was on the Boeing) would command the live engine towards climb thrust (max cruise setting), and the autopilot would look after the rudder to keep things straight and try and maintain level. As the speed decays, slow speed protection will then cause the aircraft to descend. When the other engine fails, the engines may be rotating fast enough to keep the generators online (if the Tas is high enough), if not the RAT will deploy to keep electrics. Hydraulic pumps too will keep working as long as the engines rotate fast enough. Either way the autopilot and flight controls will remain active until ground impact.
I don't think it will be the dramatic departure from controlled flight that has been explained here previously.
The 777 is FBW. It does not require trimming for power changes, only for speed changes. Once its trimmed, and autothrottles are looking after the speed its very stable, and flies very nicely hands free.
There are plenty of incidents where aircraft have continued on autopilot after the crew have become incapacitated.
If in the cruise and the fuel starvation point is reached, one engine could fail before the other. In this case, autothrust (autothrottle? been a while since I was on the Boeing) would command the live engine towards climb thrust (max cruise setting), and the autopilot would look after the rudder to keep things straight and try and maintain level. As the speed decays, slow speed protection will then cause the aircraft to descend. When the other engine fails, the engines may be rotating fast enough to keep the generators online (if the Tas is high enough), if not the RAT will deploy to keep electrics. Hydraulic pumps too will keep working as long as the engines rotate fast enough. Either way the autopilot and flight controls will remain active until ground impact.
I don't think it will be the dramatic departure from controlled flight that has been explained here previously.
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Last ping remaining fuel
Hi,
Not sure if this has been discussed: what would be the maximum remaining fuel onboard at 08:11 (last ping) ?
Knowing that:
"The latest bloomberg article has the following: "The Boeing 777 was carrying 49.1 metric tons of fuel when it departed Kuala Lumpur, for a total takeoff weight of 223.5 tons, according to Subang Jaya-based Malaysian Air."
and assuming it was still flying when last ping was made ?
Thanks
Not sure if this has been discussed: what would be the maximum remaining fuel onboard at 08:11 (last ping) ?
Knowing that:
"The latest bloomberg article has the following: "The Boeing 777 was carrying 49.1 metric tons of fuel when it departed Kuala Lumpur, for a total takeoff weight of 223.5 tons, according to Subang Jaya-based Malaysian Air."
and assuming it was still flying when last ping was made ?
Thanks
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Donpizmeof
Almost but not quite.
When the second engine fails the remaining generator and back up generator will drop off line and the autopilot will disconnect. The flight controls will then go into direct mode so you will lose a lot of the fancy stuff like bank angle protection and thrust asymmetry compensation.
The rudder trim that was added by TAC to compensate for being on one engine may or may not have stayed in depending upon how quickly the generator dropped off line. The Ram Air Turbine will deploy (although it takes a while to speed up) and then the autopilot can be reengaged. However if the pilots are incapacitated the autopilot will not reengage on its own and the flight controls will remain in direct mode. With unconscious pilots at the controls, autopilot disconnected and untrimmed since the second engine failure I would not expect the impact with water to be survivable.
However with empty tanks and a pilot flying it to a successful ditching, (much harder at night) I would have thought there was a fair chance of quite a few people surviving the impact. However the chances of getting into a slideraft and staying in it and detaching it in mountainous seas at night are probably not great.
If in the cruise and the fuel starvation point is reached, one engine could fail before the other. In this case, autothrust (autothrottle? been a while since I was on the Boeing) would command the live engine towards climb thrust (max cruise setting), and the autopilot would look after the rudder to keep things straight and try and maintain level. As the speed decays, slow speed protection will then cause the aircraft to descend. When the other engine fails, the engines may be rotating fast enough to keep the generators online (if the Tas is high enough), if not the RAT will deploy to keep electrics. Hydraulic pumps too will keep working as long as the engines rotate fast enough. Either way the autopilot and flight controls will remain active until ground impact.
I don't think it will be the dramatic departure from controlled flight that has been explained here previously.
I don't think it will be the dramatic departure from controlled flight that has been explained here previously.
When the second engine fails the remaining generator and back up generator will drop off line and the autopilot will disconnect. The flight controls will then go into direct mode so you will lose a lot of the fancy stuff like bank angle protection and thrust asymmetry compensation.
The rudder trim that was added by TAC to compensate for being on one engine may or may not have stayed in depending upon how quickly the generator dropped off line. The Ram Air Turbine will deploy (although it takes a while to speed up) and then the autopilot can be reengaged. However if the pilots are incapacitated the autopilot will not reengage on its own and the flight controls will remain in direct mode. With unconscious pilots at the controls, autopilot disconnected and untrimmed since the second engine failure I would not expect the impact with water to be survivable.
However with empty tanks and a pilot flying it to a successful ditching, (much harder at night) I would have thought there was a fair chance of quite a few people surviving the impact. However the chances of getting into a slideraft and staying in it and detaching it in mountainous seas at night are probably not great.
Last edited by suninmyeyes; 22nd Mar 2014 at 22:39. Reason: sp
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If both pilots became disabled, and unable to respond to calls from the cabin crew, would the cabin crew have any means to open the inviolate cockpit door
Quote:
Originally Posted by Hunter58
All you need is a Li-io based fire to burn the cables to the transponder and VHF3 antenna. Both go dead. And you certainly get some nice hotspot that potentially could burn a small hole into the fuselage.
Originally Posted by Hunter58
All you need is a Li-io based fire to burn the cables to the transponder and VHF3 antenna. Both go dead. And you certainly get some nice hotspot that potentially could burn a small hole into the fuselage.
One thing I am learning fast reading posts on this unfortunate circumstance, that is there is more than just a few crazy people flying planes these days.
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@F-MANU
Well, if you take it as 'pinging'=flying, whereas 'not pinging'=not flying - which is the basis of the current search effort/area - then it matters not what actual fuel was at 08.11.
Taking the above, you could assume, then, that the a/c had enough fuel to possibly fly until 09.10.59.9999....at which point, and most probably before that time, it was empty!
Well, if you take it as 'pinging'=flying, whereas 'not pinging'=not flying - which is the basis of the current search effort/area - then it matters not what actual fuel was at 08.11.
Taking the above, you could assume, then, that the a/c had enough fuel to possibly fly until 09.10.59.9999....at which point, and most probably before that time, it was empty!
Last edited by kenjaDROP; 23rd Mar 2014 at 13:37.
Everyone seems to be assuming a magic fire that can take out all the alternate communications - avoid the SATCOM and anything that prevents the aircraft flying normally - but depressurize the aircraft - and all before the hold fire warning and before the pilots notice and squawk or transmit Mayday.
The version of events in the media (lots of height, heading, and speed changes; avoids some radars; and then suddenly to make the data fit a straight flight to the southern ocean to finish on the same 40deg satellite contour as the beginning) is also hard to swallow.
I'll agree that the "pilots aren't the bad guys" scenarios require a catastrophe onboard that prevents communication.
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He would have detected the fire before ATC and ACARS was lost and would not have flown 8 hours after.
If there was a fire, we don't know where it was and how it developed.
Aviate, Navigate, Communicate
Well, if you cannot get past Navigate before whatever event it is kills you, even if your comms work, you cannot communicate. Helios did fly and none of the pilots did communicate.
Fact is, we don't know ANYTHING about what happened on board. And unless you can absoluely exclude a possibility, it is valid.
Inerting fault?
A bit of a long shot, but did MH370 have centre tank inerting fitted, and if so, do any pipes carrying nitrogen enriched air pass through the pressure hull? If a pipe were to fail, then the effect on those on board may be similar to a loss of pressurisation.
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ettore
the fire/incapacitation theory does not allow for subsequent control inputs
read back over the aircrafts known route after initial diversion
how and where it crossed the peninsula and where/what direction it was going when last seen...
the fire/incapacitation theory does not allow for subsequent control inputs
read back over the aircrafts known route after initial diversion
how and where it crossed the peninsula and where/what direction it was going when last seen...
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I'll agree that the "pilots aren't the bad guys" scenarios require a catastrophe onboard that prevents communication.
I cannot understand how eager so many people are to lay the blame for this tragedy on the pilots.