Twenty passengers on missing flight 370 worked for Freescale Semiconductors

[TheBorg]

Ok, so you'd use the autopilot to give yourself time to evaluate the problem (if possible).

So how would you evacuate smoke from the aircraft? Switch off potential causes, lower the altitude so the air is breathable when the masks run out.  Then what? Not like you can open a window.

I was in a training situation years ago with full face protection and an air tank, the room was so full of smoke I couldn't see my hand 2 inches from the mask. Even so I was barely able to see for the next 10 minutes (and I had full face coverage), I could imagine without eye protection you'd be in real trouble.

B777 Flight manual emergency checklist: (there are two other pages for SMOKE / FUMES / FIRE ELEC and SMOKE / FUMES AIR COND)

SMOKE / FUMES REMOVAL:
Condition: Smoke / fumes removal is required.
Oxygen Masks And Smoke Goggles (If Required) .................................. ON
Crew Communications (If Required) ....................................... ESTABLISH
Flight Deck Door................................................................................... CLOSE
Prevents smoke / fumes from penetrating onto the flight deck.
Recirculation Fans Switches...................................................................... OFF
Stops recirculation of smoke / fumes and increases fresh air flow.
Equipment Cooling Switch........................................................................ OFF
Attempts to discharge smoke overboard by using the equipment cooling
override mode.
Note: After 30 minutes of operation at low altitude and low cabin
differential pressure, electronic equipment and displays may fail.
Do not accomplish the following checklist:
EQUIP COOLING OVRD
IF Most Smoke / Fumes Is In Cabin Forward Of Mid-wing And Outflow
Valve Manual Control Available:
Aft Outflow Valve Switch................................................................. MAN
Aft Outflow Valve Manual Switch.............................................. CLOSE
Position outflow valve fully closed.
Concentrates smoke / fumes in the forward part of the aircraft and
attempts to remove it through the forward outflow valve.
Do not accomplish the following checklist:
OUTFLOW VALVE AFT
* * * * ~
IF Most Smoke / Fumes Is In Cabin Aft Of Mid-wing And Outflow Valve
Manual Control Available:
Forward Outflow Valve Switch ................................................... MAN
Forward Outflow Valve Manual Switch ................................. CLOSE
Position outflow valve fully closed.
Concentrates smoke / fumes in the aft part of the aircraft and
attempts to remove it through the aft outflow valve.
Do not accomplish the following checklist:
OUTFLOW VALVE FWD

So if this occurred, then it is pretty likely that some (or most) electronics would fail, with the equipment cooling set off, with the combination of a fire, and as the crew tries to vent the smoke, the fire spreads, and eventually leads to cabin depressurization, which ends up killing the crew... Plausible?

[cimmo]

So if this occurred, then it is pretty likely that some (or most) electronics would fail, with the equipment cooling set off, with the combination of a fire, and as the crew tries to vent the smoke, the fire spreads, and eventually leads to cabin depressurization, which ends up killing the crew... Plausible?

Part of the prior two smoke checklists that I didn't post advise the crew to 'plan to land at the nearest suitable airport' if the smoke/fire persists after carrying out the immediate items - turning off airconditioning packs (one at a time), APU off, recirc fans off, In flight entertainment off, cabin power off etc .

If not already on descent to a nearby airport and the pressurisation fails then the crew are already on their oxygen supply due to the smoke/fire. As this is unlikely to be an explosive depress then it isn't a huge drama, the crew will get an alarm of either airconditioning pack failure or cabin altitude climbing. They will then descend fairly quickly to the lowest safe altitude considering terrain or, as in this scenario, 10,000ft.

The crew oxygen supply (gaseous) is good for about 30 minutes. If the cabin climbs above 14,000ft then the pax oxy masks automatically deploy. I understand these are released from the overhead bin area via a barometric device and should not need elec power.
I believe MAS uses a gaseous ring main with ~15-20mins of pax oxy, but there is an customer option to fit the aircraft with chemical oxygen generators but these have less capacity.

[EEVblog]

So if this occurred, then it is pretty likely that some (or most) electronics would fail, with the equipment cooling set off, with the combination of a fire, and as the crew tries to vent the smoke, the fire spreads, and eventually leads to cabin depressurization, which ends up killing the crew... Plausible?

Whatever scenario it was, the flight control electronics (at least some of them) had to have remained active for the autopilot to still work, as the plane just flew for far too many hours for there to be no flight control at all I think.

[cimmo]

So if this occurred, then it is pretty likely that some (or most) electronics would fail, with the equipment cooling set off, with the combination of a fire, and as the crew tries to vent the smoke, the fire spreads, and eventually leads to cabin depressurization, which ends up killing the crew... Plausible?

Whatever scenario it was, the flight control electronics (at least some of them) had to have remained active for the autopilot to still work, as the plane just flew for far too many hours for there to be no flight control at all I think.

Stranger things have happened.
Do a search for "The Cornfield Bomber"

Also, if you search for "Continental Airlines - Boeing 777 flight manual.pdf"
you can read about the systems and procedures yourself (if interested).

[pickle9000]

First thanks for the info.

- "The Cornfield Bomber" = awesome
- The details on the autopilot, FMS really interesting. The fact that the autopilot maintains a turn would have never occurred to me. Sounds like you could operate the controls for both even if the cabin was heavily smoke filled.
- Reading the smoke in the cabin routines I can see that it is geared around the air supply for the pilots. Not a good situation no matter what.


I'm not big on the speculation stuff but man a fire sure would fit. Takeoff to loss of contact about 40 minutes, 50 minutes later the last primary radar contact. 30 minutes worth of pilot oxygen. It would be interesting to have seen an image on takeoff I wonder if the nose gear (tires) could have caught fire. I'd expect that there would be a smoke alarm in the landing gear storage areas. Be a bad place for a fire though.   

I do wonder about the statement that the FMS was programmed with an incorrect waypoint prior to liftoff. I would assume that a pilot would notice that. I wonder what the actual source of that information was and if there was a possibility of having it keyed in wrong (96 instead of 69 for example)?

[tom66]

In a fire, the flight data and cockpit voice recorders often fail, which in a way could be useful for the investigators as they would have the moments leading up to the fire on the CVR (which normally only records the last 2 hours.)

[Sionyn]

Content removed

Another user got taken to task for posting conspiracy theories in this thread.
It's only fair that everyone is treated the same.

[GeoffS]

Reports that a Chinese vessel has detected a signal on the frequency of the  black box beacon.
Location reported (' about 25 degrees south latitude and 101 degrees east longitude')  is far to the north of the previous search area.

Link here:http://news.xinhuanet.com/english/china/2014-04/05/c_133241023.htm

[Wytnucls]

All the media is running with the story. Not confirmed yet. The Chinese navy is under a lot of pressure to find something.
Someone involved in the search for the SAA Helderberg said that, at the time, the ships' detector sensitivity was turned up so high, that many false pings hampered the search for the aircraft, with constantly changing search areas.
I hope this is a valid detection, but the laws of probabilities are really against it.

[SeanB]

Funny enough I was at my local Ham meeting today, and there was an old EPIRB, made in 1997. Battery very flat, not surprising seeing as it expired in 2008. Tried the self test and it barely beeped, no strobe etc. Would have bought it to tear down but had already spent $20 on buying a nice Fluke 1900A frequency counter ( no options installed) that was there as well. Tried it out and it works, mae in 1984. Only issue was a cracked display hold down collar, which was replaced with a plastic sleeve and a drop of glue. everything else works. Not worth making the battery back up board and installing it, and in any case I would prefer to use higher density batteries other than NiCd. Only need to make an inverter to give the -12v rail and a 5v rail then.

[ivan747]

I have seen this map become more and more hopeless over time. They left coordination and planning at home it seems 

[pickle9000]

That's a massive amount of ground (ocean) to cover. I can't even find my keys in the kitchen half the time.

If the Chinese have actually found the box then that's pretty amazing, I'd imagine the background noise would be deafening.

[Sionyn]

black box signal found according to sky news;
Radar expert Professor David Stupples told Sky News:
If there has been a signal received, it could be the black box or it could be something extraneous. "I don't know anything (else) that puts out the 37.5kHz signal."

http://news.sky.com/story/1237620/missing-plane-ship-detects-signal-in-ocean

[pickle9000]

I wonder what the procedure would be? They are pretty far from the search area, I guess that would make it quieter, I suppose they are checking without engines running as well?

[IanB]

But, again, airplanes have no stability in roll. Some can be highly damped, which is what you are talking about. But no airplane is self-righting in roll.  A control loop must be added to keep the plane's wings level -- the pilot looking at the horizon, the pilot looking at the gyroscopic instruments, or an autopilot.

If this were true, then uncontrolled model gliders could not fly. Yet they manifestly do. Such a glider if subjected to mild roll disturbance will return to stable, level flight all by itself. Only if the size of the disturbance crosses the stability threshold will the aircraft pitch downwards into a dive.

[IanB]

Airplanes have no natural roll stability with respect to the ground. Dihedral only functions in what is called 'uncoordinated flight' which deals with the orientation of the aircraft with respect to the relative air stream. Dihedral is added to make airplanes 'easier' to fly, not to give them self-righting ability.

This argument does not have logical consistency. The force vector due to gravity always acts at the aircraft's center of mass and points towards the ground, regardless of the direction of any local air currents. Therefore an aircraft in flight is always referenced to the ground. Only an anti-gravity machine could take that away.

[CaptnYellowShirt]

Well, don't take my word on it.

Boot up your flight sim, load a B777, and see how far you get.

[EEVblog]

Just heard on the radio that the Australian ship has also picked up a ping, but NOT on the same area as the Chinese ship 

Secret CIA controlled sub, or giant octopus mating?

[pickle9000]

Water layers?

[SeanB]

Thermoclines and layers of different density ( salinity) can duct sound for very long distances. They were used by submarines to hide from active sonar or to hide from passive listening by staying just outside a layer while moving and this hid them from detection. You could also pick up subs a long way away and think they were close by from the volume, the layer acting as an acoustic waveguide.

[BravoV]

Just a wild thought, is there any chance even remotely that the sound was one of the harmonic from other non nature sources like from ship/subs engine ? I'm not sure exactly what I'm talking about here, its just pop out from my head.

[tom66]

It's 37.5kHz 10~20 cycle burst about once a second. Whilst not impossible, it's very unlikely it could be from another source... unless it's another plane transponder or something similar.

[eurofox]

Just heard on the radio that the Australian ship has also picked up a ping, but NOT on the same area as the Chinese ship 

Secret CIA controlled sub, or giant octopus mating?

You guy's got strange spiders and snakes in Australia but more surprising local octopus that have sex generate that 37.5 Khz ultrasound when getting an orgasm 

Yeah you got even an Belgian minister over there in your government so everything is possible 

[EEVblog]

Just a wild thought, is there any chance even remotely that the sound was one of the harmonic from other non nature sources like from ship/subs engine ?

No. There is a 37.5KHz carrier and a 1Hz repetition rate. To get these two combined with anything other than the purpose designed transponder is just too silly to even contemplate.
If this was any other regular air crash investigation, they'd be reporting unequivocally that they have found it (or heard it at least). But this is MH370, the most botched investigation/search/official screw up of all time, so they are just playing silly games and once again trying to cover their already spanked arses.

[pickle9000]

Thermoclines and layers of different density ( salinity) can duct sound for very long distances. They were used by submarines to hide from active sonar or to hide from passive listening by staying just outside a layer while moving and this hid them from detection. You could also pick up subs a long way away and think they were close by from the volume, the layer acting as an acoustic waveguide.

I guess that would mean both the sender and receiver would be in the same layer.