Here's the typical route for the Atlanta to Johannesburg flight I do once in a while:

http://flightaware.com/live/flight/DAL200

As you can see, it is out over water, well away from any radar coverage, or VHF radio coverage, for 90% of the flight. Luckily (for me) most of the way we do have Satellite comm via CPDLC with various controllers along the way, starting with NYC, then Santa Maria, then Abidjan, Dakar, Windhoek, and finally Joburg.

We use HF as a back up, but we have zero radar coverage most of the way, only over land in the US and in Africa.

Here's the track for a typical ATL-Dubai flight, I just flew this a few days ago.


http://flightaware.com/live/flight/DAL8/history/20140313/0150Z/KATL/OMDB

As you can see, you have much better radar coverage because you are over land much more, only out of radar contact up over the north Atlantic for about four hours. We have CPDLC the entire way over water there however, and also use HF for back up. Over land, we use VHF most of the time, unless we are wayyy up into Canada going on a Polar route, to say Shanghi out of Detroit.


http://flightaware.com/live/flight/DAL583/history/20140313/1720Z/KDTW/ZSPD
We go straight north out of Detroit, over the north pole, and down the back side, so we have no radar and no VHF and even the HF won't work too good up north of 72 degrees north. Sat com works most of the time up there though, which is nice!

Here's the Tokyo to Singapore route I used to fly quite a bit, as you can see, they put an Airbus A330 on the route lately, so I'm not flying there any more, but it may come back to the 777 in the summer. You can see it's over water a lot more than over land, and we are out of radar coverage quite a bit, and using CPCLC most of the time for communications with ATC.

http://flightaware.com/live/flight/DAL621/history/20140313/0900Z/RJAA/WSSS

We really need to get the third world to buy into sat-com and get better coverage, and stop using HF. Also, Radar has limitations out over water, because it has to be physically mounted to something, ie. a land mass, or a ship, and it has limited range. I doubt any third world country is going to spend the money to put a ship on station just to monitor airline traffic.

Wow, Timbo. Even if you were lucky enough to successfully pull off a "Sully," those polar routes are so remote, you're not getting any real search and rescue until way too late. Can't be a comfortable feeling if you allow yourself to think about it.

As an aside, the best CNN can do right now as an "expert" is Bill Nye the Science Guy??? Wow.....

Mike

Yeah, they are woefully short on experts!

And Richard Quest??

Spare me!

He may be an expert -passenger- but he's got his head up his butt when it comes to anything technical!

Here's what he's an "Expert" at:

http://cityroom.blogs.nytimes.com/2...arge/?_php=true&_type=blogs&_r=0

When I was flying KC135's in the military we would go on very long deployment flights, "up north". They would give us a .38 handgun, one, for the whole crew! It was supposed to be for self defence if we went down in 'unfriendly territory' (cold war era) but we all knew it was so we could kill ourselves, if we survived a crash landing in the artic or in the ocean!


There were 5 crew and 6 bullets...just in case you missed.

Interesting...thanks for the info Timbo.

So, with all of the theories abound, I'm with you...some sort of catastrophic electrical failure followed by sort of incapacitation. If it was a hijacking, that was a failure - because usually they want to make some sort of statement with it.

But, a couple of questions: if they had an electrical malfunction severe enough to take down all communication options AND cause them to descend to clear smoke, would it have affected other fly-by-wire control systems or autopilot? How separate are those systems? You've also got other people on the plane - flight attendants, etc. It would have to be pretty bad to get everybody. What are the chances of an electrical failure that caused a couple of issues including a depressurization that might have gone somewhat unnoticed - maybe that electrical failure affected the instruments that indicated the problem? I know you should be able to recognize that but we had that private jet several years ago with a faulty door seal that knocked everyone out.

There are warning horns that go off if/when the cabin altitude gets above 10,000', just to warn you of a slow decompression, which was not the case in the Paine Stewart jet. They had a slow decompression from the door seal, but no warning system for high cabin altitude.

On the 777, there is one central location where all the electrons come together, that is in the E+E compartment, which is under the floor just aft of the ****. It's a very small space filled with all the computers, for all the systems and the radios, transponders, etc. Everything electrical passes through there on it's way to somewhere else. There is also a 'master computer' which is called the AIMS Cabinet.

Many times when we get on the jet, there are 4 mechanics in the **** trying to do a "Reset of the AIMS cabinet" because the airplane is giving them all kinds of stupid nonsense messages. It's a computer, sh!t in, sh!t out, so like any Microsoft product, they'll shut it down and reboot it, then run all their systems tests, again, and hope the status messages go away. This takes about 30 minutes.

Just last month a Captain friend of mine had to go 'down in the hole' to reset some circuit breakers for the SATCOM system which had quit working. They had to call ATL Maintainance on the HF radios and get instructions on where the CB's were, then go back into the first class cabin, pull up the rug, open the hatch, and climb down into the E+E bay to reset them. This while they were cruising at altitude over the south Atlantic, from Joburg to ATL.

So...it's not unheard of that something in the E/E compartment could go wrong. What other systems it takes out depends on what went wrong. If it was bad enough, it might knock out the transponders and radios, then start a smoke/fire event.

Remember the 787's battery overheating problems? Yeah. And that was a brand new airplane. These Malaysian 777's are 10-15 years old, who knows how good their mx on them is? Do they reset their Aims cabinets when they get a bad status message, or just say, "You can go without it, you'll be ok..." because they don't want to take a 30 minute delay. And what was the history on this particular air frame? They track mx issues specific to airframes. Did this one have a history of E/E issues? Nobody's saying yet.

If that's the case, you can understand why the airline officials would -not- be forthcoming with that info. It puts the blame squarely on them and their shoddy mx....IF that's the case. I'm just speculating here. I don't know what they consider a mx no-go issue. I know I don't leave ATL unless the airplane is 100%, due to my butt being out over the water for 14 hours, or over the north pole.

If the smoke/fire was bad enough to kill the pilots, the pax were dead too. All the air circulates throughout the entire airplane, which is why you would want to descend below 10,000' and shut off the pressurization, to stop the smoke circulation. The pilots have oxygen masks of course, but only about an hours worth of O2, if the bottle was full when they left. Sometimes they are only half full when you leave. Yes, we check it. I don't know if they do however.

If they got it turned around and descended to 10,000' and pointed it west, but then were overcome with smoke...it will fly on autopilot until it runs out of fuel, again, depending on how bad the fire was in the E/E compartment. Even if the autopilot stops working, the airplane is in trim to fly straight and level, it will amble along by itself, just like a sailboat will, going downwind if you've trimmed the rudder pressure to about zero then you fall overboard while taking a pee, it will go on without you, until some air bumps upset it enough to send it into a banking turn, then it will just slowly spiral into the sea.

It is very strange, and the 777 has not had any inflight fires in the E/E bay to my knowledge, but it may have been a hijacking with a couple morons who thought they could make it to Pakistan or...? BUT...if they were savvy enough to know to turn off the transponder, they also should have known how much fuel and what type of range they had to work with, and made it to where ever they were going.

I still think it was some type of mechanical issue and it went into the ocean or jungle.

OR...it was hijacked and ended up in the sea. Either way, that's a lot of water to search. Remember the Air France flight that went down off South America? The search party had a very good radar fix of exactly where they were, but it still took them two years to find it.

If one of the pilots had decided to go rogue, he would have had an airport in mind and been there by now, and we'd have heard about it. You can't hide a 777 for very long, even in the third world. If one of the pilots had wanted to kill himself, he would have just rolled it over and gone straight in, transponder ON, not off, what does he care about radar coverage, he probably would have made a radio call too, like "Adios MF'rs!" I doubt he'd fly along for 4 hours waiting to die.


Now, do we "Trust" the Malaysian radar data? Do we trust the "Pings" they say had it flying along west bound for four hours? Or should they go back and search the last known position again?

They would be better off with Jonny Quest

one news story hinted at some cracking around the base of the antenna arraw, which may have failed in this case, causing the communications blackout.

plausible (also would explain the course change if that's what happened) but wouldn't explain the disappearance unless something else happened to incapacitate the crew/pax.

i suspect that if crew loses the antennae, but were otherwise unharmed, they could still manage to find a runway to set down.

so, were possibly looking at:

something that incapacitated the crew as well as the airframe, but
wasn't instantaneously catastrophic (no debris field in flight path)
no "adios m-f'er" and no transponder, so not likely a human act
no crew or computer awareness of problems before last communication

was there any weather that night? maybe lightning strike? meteor hit?
ground /air to air missile?
front fell off?

The weather was clear.

A failure in "the antennae array" would require multiple other unrelated issues to occur at the same time. They should still have other methods of communicating (Tim can probably comment). I also would find it difficult to believe that all of the communications antennae are housed in one unit.

There are several different antennae on the belly of the airplane and a sat com sender/receiver on top, so a failure of just one would only affect that one radio/transponder. Everything is redundant, except the AIMS Cabinet, that's the weak link and it controls... everything!

We have 5 generators, 3 hydrolic systems, 6 fuel pumps, two in each tank, 2 pressurization systems, electronic engine controllers, three autopilots, two independent GPS/Nav systems, etc. but they all run through the E/E bay and AIMS cabinet, and it even has a 'dumb mode' to back up the normal mode...but if the whole thing catches on fire, or shorts out for some reason...not good!

and if the AIMS cabinet "breaks", what happens? Can you still fly?

I saw something about the antenna issue. Sounded like cracks in this area of the fuselage could lead to rapid decompression (probably a default effect in their risk assessment process). So, if that report was correct, it wouldn't necessarily be a simple as let's just grab the backup.

Of course, the media tends to blow all of these things out of proportion...

Mike

It's a pretty complex piece(s) of equipment, with many functions, but the flight control computers run through there, and some of the navigation stuff, and the autopilots, so if those go out, you are screwed...but it's never happened (to my knowledge) in flight, so unless there was a fire in that area, which caused overheating and damage to the AIMS, I doubt it would fail like that.

A rapid decompression would cause you to want to put on your oxygen mask immediately and begin an emergency descent to 10,000', and a turn towards the nearest airport, perhaps that's what they did, but that shouldn't cause both transponders and all radios, 3 VHF, 2 HF and 1 SATCOM to fail. They should have been able to put out a distress call if it was a rapid decompression, and they should have been able to breathe without an 02 mask once they got below 10,000' and they should have been able to navigate to a suitable alternate and communicate with ATC...Unless...they were overcome by smoke and fumes. They might have done the first part, then passed out and the plane just flew along at 10,000' until it ran out of gas.

I just wish the idiots on CNN would get out of that 777 Simulator and stop showing the Al Qaeda Wannabees how to turn off the transponder and operate the autopilot!

CNN YOU ARE MORONS!

Yup, serious Face Palm stuff!

Isn't there some sort of automatic countermeasures system that would take care of a fire?
In datacenters they use special gas to extinguish fires without damaging the computers too badly.

I still think it's odd that there where two Iranians on board with fake passports, although it could be completely unrelated (traveling under the regime's radar?).
What if they just stole it? Biggest heist ever?

At least one of the guys flying on a stolen passport was vetted out as legitimate...just traveling illegally and probably with an eye toward illegal immigration (and possibly part of a human trafficking business). I remember a report that his mom was waiting for him and she was interviewed by the gobermint. The media scrutiny appears to be off those two for the time being.

There are fire extinguisher bottles for both cargo areas, forward and rear cargo compartments, but the E/E bay is separated from the fwd cargo hold, by a bulkhead wall, there is no fire extinguishing system in the E/E compartment other than a smoke elimination venturi valve type thing, which uses differential pressure to push the smoke out the valve...

And 60% of the time, it works every time!

Hey, hey, hey...if everything worked 100% every time, us engineers would be out of work.

So am I the only one who thought "rapid decompression" was just code for ka-boom???

I forgot about the small handful of times that jetliners have sprouted moon roofs and managed to land with most of the people they had aboard when they left the airport...

Of course, until the Captain Sully video, I also thought that floating seat cushions were only on the plane to keep everyone busy as they fell to a horrific death. I know, you're supposed to wait until AFTER the "water landing" to put those on. But, has there ever been another successful water landing? Is it even possible on ocean waves?

Mike

EDIT: Jake, if more users knew how to write user requirements (OK, knew what they need in the first place), your success rate would skyrocket...