The best part of this theory (which I think is good) is:
"Losing Helios 552 might be a freak accident, but if decompression and a locked door led to the loss of MA370 as well, then this would be a new threat that will now have killed 360 air travellers—many times more than have died as a result of hijackings since 9/11.
Is it appropriate to employ anti-hijacking measures to prevent violent hijackings a couple of times per decade, if they run the risk, as a side-effect, of crashing in-service airliners a couple of times per decade?"
That's funny! When has there ever been a proportionate response to the threat of terror? The response to 9/11 was so over the top and all out of proportion to such an mind-boggling degree that the idea that they would address this is a bit ridiculous. Even if hundreds of thousands die to prevent one plane being hijacked, it would all be justified as just what needs to be done to fight TWOT. National Security!!
There is a code that can be used by the cabin crew to access the cockpit in this cases. It's cancelable from the inside, so if a hijacker tries to use it you can put it of once it starts ringing(it rings for 30 seconds and then opens the door). So this case of pilots unconscious is covered.
Any way I agree that the spending after the 9/11 is insane and unecessary.
It's been assumed that one flight attendant on the Helios crew eventually managed to open the cockpit door and he did sit down at the controls (this is according to observations made by the fighter jet escort). It's likely that he was the only one still alive on the plane by that time - certainly he was the only one being conscious - and that was because he must have used a portable oxygen canister instead of the integrated ones in the cabin. However, he was unable to gain control of the aircraft at this point, probably because he was too severely handicapped by oxygen deprivation. His being alive was already vastly improbable and sadly it wasn't enough to save everyone.
In a similar scenario, everybody onboard the Malaysia Air flight might have been dead or in a coma for the entire duration of the emergency, so it probably wouldn't have made any difference if the cockpit door could be opened from the cabin or not (which might turn out to be a misguided concern anyway since there's a cabin crew access code).
> * On February 22nd, aircraft 9M-MRO underwent maintenance. During this, or during a previous maintenance cycle, an empty oxygen bottle was installed by mistake for a full one, or a valve was jammed, or some other undetected fault rendered the flight deck crew's emergency oxygen supply inoperable.
That sounds extremely unlikely. Standard procedures for equipment checks in plane are usually done at 9 sigma standards, i.e. they involved numerous checks by different people. We're not talking about an amateur doing maintenance at home during the weekend. And I doubt there would be a single oxygen source in the cockpit since airplanes are usually built with multiple redundancies.
I don't really buy that one. Plus the plane did not make it to any military radar either - so where did it fly for 5 hours?
The other thing to consider is that there are roughly 90,000 flights/day and 365 days in a year, so even if such an event has a probability of 1 in a billion (that's roughly 9 9s reliability), you'd expect it to happen once every 30 years on average. Extremely unlikely events become plausible when large numbers are involved.
If the cause of the accident is in any way related to "human error" instead of unpredictable failure (unpredictable as in photons causing a bit flip that can't be caught in error correction, not something like a part with a 15 year life span being used for 20), chances are that error is the result of an institutional problem. With 90,000 flights a day I can imagine plenty of people making mistakes during maintenance and flight checks because they're tired, having trouble with at home with the family, etc. but that's why we have so many levels of review and confirmation, checking to make sure it all goes according to plan. If the airline (the asset/floor managers specifically) don't enforce a culture that takes safety and aircraft operation seriously, no amount of reviewers will help them and when things fall apart, they do so in spades.
It's not really a question of "what's the chance that this will break in 30 years." It's a question of the part's function, the added complexity/failure points it adds to the design, and the chances that the added complexity will exacerbate flaws in management when it all goes haywire.
> I can imagine plenty of people making mistakes during maintenance and flight checks because they're tired, having trouble with at home with the family, etc. but that's why we have so many levels of review and confirmation, checking to make sure it all goes according to plan. If the airline (the asset/floor managers specifically) don't enforce a culture that takes safety and aircraft operation seriously, no amount of reviewers will help them and when things fall apart, they do so in spades.
If that was really the case, planes would be failing every single day and air crashes would be as common as train wrecks and car accidents. It's far from being the case, so it says a lot as to how reliable planes are made to be, and how serious the maintenance is done on planes. Besides, companies have no incentive to skip on safety checks because they know a crash would have immediate, and serious impact on their image and direct sales of tickets.
This was not the same place (737 is damn old in design, from the 70s, 777 was designed in the 90s), this was not an international flight (security standards for international flights are stricter), so I'm not sure he even tries to compare both of them. Why not reference a Cessna incident as well ?
Did it cross your mind that it could be a combination of them? Drop the accusatory tone when you don't understand the content.
International flights have higher standards due to extended distances from emergency landing sites. An old plane is not exempt from the check standards, but the age certainly means that there is an increased probability of failures.
>If so, at what airframe age, or travel standard, or aircraft size does that kick in?
Again, sarcasm is really unhelpful when it's just a result of you lashing out at a comment you didn't understand.
Did it cross your mind that it could be a combination of them? Drop the accusatory tone when you don't understand the content.
Do you not see the irony in writing an accusatory reply to me? ;-)
To your main point, I understand the content; I do, however, resent people boldly stating "that can't happen, it's too unlikely," only to then say "Oh, right, yeah, if you exclude old planes, domestic flights and blah blah blah blah blah."
I do concede that it would be more helpful if I was less of an arse about it though.
This is an interesting article. One of the comments also gives another plausible solution. Pasting it here for convenience:
"There are a number of troubles with that theory Charles, one of which is that the plane should have followed its intended course and stayed on radar by passive reflection, but it is certainly also one of my favourite theories right now.
The lack of debris near where it disappeared from the radar opens the door to more "interesting" theories, such as kidnapping or theft.
First of all, identifying planes by transponder code is not hard ID.
It would be perfectly possible for co-conspirator plane to fly transponder-less up to the target plane, take over the transponder code, and fly decoy on the official route, while the MH370 goes elsewhere.
That means that the point of "last contact" doesn't tell us anything but the existence of an electronic device acting like a transponder at that time and place.
Turning the transponder off and tailing another transpondered plane very closely is another way to disappear from ATC without plastering the surface with debris and then you are also more or less free to go wherever you want, until somebody visually spots two planes very close.
The decoy plane does not need to be the same size, so the probability of such visual detection would be low.
Therefore, suspecting foul play, we don't have any trustworthy information about the planes whereabouts after the last visual sighting of the plane.
It would be interesting to know if there were any high-value targets on that plane, amongst the passengers or in the cargo.
If the cargo was the interesting bit, killing off all the passengers by dropping pressure and oxygen is trivial.
One interesting nugget is the rumour that "passengers phones are still ringing".
That's sufficiently implausible that nobody would take it seriously and actually follow the SS7 data.
But if true, it would be explained by the plane sitting somewhere at the edge of a jungle, for instance on the remains of an old WW2 strip, passengers dead, and cargo gone."
>It would be perfectly possible for co-conspirator plane to fly transponder-less up to the target plane, take over the transponder code, and fly decoy on the official route, while the MH370 goes elsewhere.
Since we know nothing, a lot remains open, but that is some of the most bizarre conjecture I can imagine. A 777 flies at an altitude and velocity because it is optimal. Arrive at the right altitude and location, spoof a transponder, and replicate a believable velocity?
Who could do that? The US, Taiwan, China, Japan? And yet, if any of those used something like an Aegis class missile cruiser to launch something we haven't heard of before, it would still be absurd, since this will draw more attention and resources devoted to investigating the cause than even something like the murder of JFK if it is a big enough mystery.
Someone with the resources of a nation state (most likely necessary to spoof and replace a 777 at cruising altitude) could also figure out other ways to assassinate a person that are less likely to be sufficiently investigated to decipher.
Since transponders are trivial to spoof and interception is a matter of coordination and a radar, you're looking for anyone who has a plane that can fly ~500kts at ~35000 feet for a while. So...pretty much anyone who can afford an old Gulfstream 3 or Boeing 707. John Travolta, for example. Nation state not required.
Here's one potential problem with that theory... that plan was equipped with an onboard GSM microcell, right? So people could still use their phones? These should run over a different set of antenna, so if the other set was ripped away, this satellite link should have still worked.
So, if something like this theory happened, why didn't someone in the main cabin use their phone to call home?
Unless everyone suddenly lost oxygen at the same time...
Time of useful consciousness after loss of pressurization at a typical airliner's cruising altitude is about 15 seconds. Your lungs basically operates in reverse and pump the oxygen out of your body as fast as your heart can beat. Once that deoxygenated blood hits your brain, it's lights out. I'd be rather impressed if anyone was able to make a phone call within 15 seconds of an explosive decompression. Presuming it was explosive, of course.
I'm curious why there isn't redundancy in oxygen supplies? Under such conditions would the crew at least be aware enough to know the oxygen tank they are drawing from is faulty and that they need to switch to the backup tank.
Damn that is an interesting theory. I think there should be a way of getting into the cockpit if it can be determined that the pilot and copilot are incapacitated. That would be a miserable way to go. :P
Here is what I don't get. A plane, a HUGE plane, supposedly just disappeared. Near China. So this whole "fly under the radar" is just BS? You just need to turn off your transponder, and you can fly wherever you want?
The range at which Radars can detect planes is a lot shorter than most people seem to believe. Ground based Radars have an effective range of something in the region of 200miles due to the earth's curvature. To get around that you either have to have air based Radars (such as the E2-Hawkeye used by US carrier groups), or more exotic/experimental types of radars which bounce off the ionosphere.
The limitations of radar are part of the reason why Aircraft have transponders - you can pick up an actively broadcasting radio from far greater range, and you're not relying on getting a clean bounce back from the aircraft. They're also the reason why carriers carry multiple E2s - a radar on the top of a mast on a ship simply can't see far enough.
In addition, the critical frequency for the ionosphere is ~10MHz (that is, above that frequency, you can't really bounce a meaningful amount of energy off the ionosphere, most passes through). 10MHz = a wavelength of 30m. So in general, you'll only be able to detect things about 100ft or larger in size (and that's a lower limit-- practical is probably bigger). I'm not at all surprised that you'd need line of sight to track a plane. Knowing that there's something there is easier, but tracking is trickier.
Every countries spend literary billions to develop radars, stealth fighters and ways to disrupts radars. Now, we understand in a closed area watched by several nations and operating by clear weather, they can't effectively localise one big civilian aircraft? For 4 hours? Because just the guy turn off transponder?
I think either we have been seriously mislead of what our technologies capabilities are or one of states of the area in knowing more than it said.
Most of the detection platforms referred to in the "billions to develop" are meant to operate as needed, in time of crisis. They're simply not an "always on" affair, and operating costs for airborne detection platforms are expensive. There simply is no need to operate AWACS 24/7 except where a threat of conflict is involved.
Moving to ground radar, many counties simply don't have total coverage. When a transponder works fine the vast majority of the time, and peacetime is the prevailing norm, there isn't a cost justification for it. The prices involved in covering fast stretches of ocean and remote islands with radar coverage is a hard sell.
>You just need to turn off your transponder, and you can fly wherever you want?
Just from reading comments in the linked piece, it seems that is true for some parts of the world. The malay military didn't have an operational air defence radar system, or they might have had a better idea where it was going. And there are areas around the Bay of Bengal with no radar coverage either, which, if the plane was hijacked, might be where it headed.
Yes. I am astonished that you do not already know that.
On 9-11, the combined maximal efforts of civilian and military aviation were unable to locate four airliners because their transponders were turned off. This occurred near the New York and DC metropolitan areas, some of the most carefully controlled air space in the world.
Without a transponder, an aircraft is just a raw radar return among, potentially, hundreds or thousands of other returns from civilian and military aircraft, weather, birds, balloons etc. Add to that glitches, ghosts and anomalies in busy air space and it is not surprising that a large aircraft without a transponder can hide in plain sight.
There was no real problem locating the four airliners hijacked on 9/11. In fact, one of them (United 175) didn't even turn its transponder off. The other three were adequately tracked with primary radar. The problems with the airliners that day were deciding what to do about them (e.g. intercept them) and then actually doing it (e.g. no procedures were in place to quickly scramble fighters in a case like this).
Primary radar is difficult and inconvenient but it's not nearly as difficult as you make it sound.
This is not true; the difficulty in using raw radar returns to manage and defend the domestic airspace was the primary reason the FAA grounded all civilian aircraft on 9/11--to clean up the scopes.
Andrews scrambled two (unarmed) F-16s to intercept flight 93; they just followed the Potomac north because no one knew where that plane was. Even after the PA crash was confirmed, those fighters spent hours contacting radar returns to check them out and get them to land.
That just shows that primary radar is difficult to use, and that it's hard to track a plane on radar after it's crashed. I'm not disputing that. Perhaps "no real problem" was bad phrasing, what I meant was that they were able to track them and they were not "unable to locate" the planes.
Pretty much no. There is essentially no possibility that this plane flew over, say, Vietnam or China undetected just because it turned its transponder off. There are only a couple of possibilities, in rough descending order of plausibility:
1. The plane exploded or immediately crashed roughly where the last known contact was made. No debris has been found because... well, that's a weird one.
2. The refuted claim that Malaysian military radar tracked it to the Strait of Malacca is actually correct, and it crashed over there somewhere.
3. The plane continued flying but stayed over the open ocean, far enough from land that there was no primary radar coverage, and eventually crashed into the ocean somewhere far away. There isn't a whole lot of room for that in this area, of course.
4. The plane eventually flew over land but the local air defense people were asleep at the switch. It subsequently landed or crashed in that country or in the ocean beyond.
5. The plane eventually flew over land and was tracked by primary radar but this is being covered up, either to hide incompetence, or as part of some crazy plan where the plane was hijacked and stolen by that country.
IMO anything beyond #3 on this list is seriously far-fetched and not a realistic possibility, but I wouldn't rule them out completely at the moment.
Just 10 years ago someone has stolen a Boeing 727 from an airport,took off, turned off the transponder and landed somewhere. Even FBI looked for that plane and couldn't find it. So I guess it's very much possible to fly undetected.
This begs the question: why on earth is it even possible to turn off a transponder mid-flight on a commercial plane carrying hundreds of human beings? I also don't understand why, if we can send bursts of engine data every 30 minutes from the middle of the ocean, we can't send a GPS location every couple of minutes. Maybe even throw some GPS data in with the engine data - at least we would know where it was within a 30 minute window. We're talking about a few extra bytes.
Transponders have to be turned off while you're at the airport and while the plane's being serviced on ground. I think 777 has 2 transponders, so you also need the ability switch from one to the other. Lastly, I believe all electronics on the plane must be on a breaker circuit in case of electrical shorts so that pilots can isolate and turn off faulty circuits.
The simple answer is you have dozens of planes on the ground at airports, which you don't want to appear on all the radars. Yes, a technological fix would be trivial, but those systems were designed decades ago, when being a pilot was quite prestigious and well paid. The thought of a rogue pilot never occurred, I guess.
Locaiton data is sent by the ACARS system, which was apparently turned off.
You don't need a transponder to show up on radar, it just makes it a lot easier.
Radar operators have a hard job telling a plane from clouds or echos. A transponder makes that job a lot, lot easier.
However, if you have a good radar system, you can happily track the contact without a transponder. In fact this happens all the time, I had a very nice chap at Farnbourgh West LARS (Low Altitude Radar Service) do this for me, when the shed I was flying had a little bit of a failure. For newewer systems such as those used by NATS automatically keeps the data assigned with the trace, using their proprietary algos to filter the noise.
If this happened over the UK, the transponder went off, ATC couldn't reach them, then a couple of Typhoons would be sent up to go have a look, and if need be escort.
With this background understanding of how modern Radar services are used piratically, taking into account a bit of background of the Malaysian authorities (short version: no terrorist attacks have ever happened even with our extremist religious views, honest.) Then this article will make some more sense:
It is becoming clear they knew full well what was going on. They had the ACARS data. They had contacts on their radar, which they would have understood to be the plane, if not at the time, soon after. (But they really should have understood at the time!).
This stuff happens all the time in air safety investigations. See Egypt Air, or Air France!
This is my issue - an aeroplane disappearing from SSR and not making contact on the next frequency = sends up someone to have a look. Perhaps Malaysia's air force isn't as trigger-happy as here in England?
P.S. Never thought I'd see Farnborough West mentioned on HN! Hello fellow South Eastern pilot.
Why not have two types of transponders, one that is always on like lojack for planes and one that is only on for planes in the air. As long as there is some information being sent that determines what kind of signal it is, it should be trivial to have a radar system that filters out those only broadcasting their always on system.
It's probably less of an issue on larger/more modern planes where your squawk code is entered with a numeric pad - but on older/less complex planes you have to switch off the transponder when changing codes since it's a series of rotary dials and you don't want to accidentally broadcast an emergency code (7500/7600/7700) even for a second as it would trigger all sorts of alerts for the controller.
I should point out that I don't know what is true. It just seems to be a contradiction that every passenger can take on board and use whatever they want in-flight, yet transponders specially engineered to be safe on a plane must be able to be disabled.
I suspect the answer is that the transponder doesn't need to be under the control of anyone on the plane.
Maybe it has to do with the location on the transponder? A laptop in baggage or an electrical component buried deep in the bowels of the plane would be hard to get to in the event of a potential fire. A passenger's laptop would be fairly easy to put out with a fire extinguisher.
This device is a bigger piece of equipment using more power, with physical interconnects to other areas on a plan. Moreover it normally not located a place where you can lift it up and throw it in a bucket of water, or rip out its battery if something should go wrong.
I remember watching a "Mayday: Aircrash Investigation" episode (awesome series by the way) from the 80's I think.
It involved an Eastern passenger plane that had miscalibrated it's guidance system and strayed into Soviet(?) territory during a politically tense period at the same time a US spy plane was in the area.
The Russians(?) shot the plane down and it nearly started a war. The country the plane was from didn't believe it had strayed as far as the Russians(?) said it did.
Eventually, the US government released radar data showing the position and path of this plane so that it would avoid a war. It showed this particular plane had grossly gone off course and entered Russian territory. The radar they had was capable of tracking every plane in the world 24x7. This was back a couple/few decades as well! Turned out the plane has set the wrong guidance system pre takeoff which was a terrible and extremely rare mistake. The US held out until the last moment to release this data as they didn't want anyone to know they had the capability.
This leads me to believe some people somewhere know where this plane went down.
I am not sure if I am recalling this precisely, but I 100% remember that the US government back then apparently has this radar tech.
There's nothing in the wikipedia article about the USA's ability to track planes. We did have a radar station in AK, which may be what you're thinking of? According to wikipedia it didn't produce useful information, and wasn't necessarily tracking the plane at all points anyway: http://en.wikipedia.org/wiki/Korean_Air_Lines_Flight_007#U.S...
I don't think we've ever had the ability to track all planes in the world.
It'll take me ages to go through all the episodes of Mayday, but I'm certain in one of them the US released highly classified radar data to prevent a wider political catastrophe, and that the narrator described the source of the data was from a new type of radar that had the capability to track every plane in the world.
The series is exceptionally well researched and presented.
"Aviation investigators and national security officials believe the plane flew for a total of five hours, based on data automatically downloaded and sent to the ground from the Boeing Co. 777's engines as part of a routine maintenance and monitoring program."
Well, if the engines were transmitting, can't someone figure out the direction of the plane?
> Well, if the engines were transmitting, can't someone figure out the direction of the plane?
Unfortunatley not; the flight-data transmitting systems ( ACARS and ADS-B ) that do include position data appear to have been turned-off or disabled deliberately.
The engine telemetry feed is part of Rolls-Royce's 'Power by the Hour' system, which aims to identify faults or under-performance in the engines whilst still in-flight so that an engineer can tune and correct when the aircraft arrives. It doesn't care where the aircraft is.
Though... it might include environmental data such as inlet pressure and temperature, which could help to determine altitude.
If the system sends signals EXACTLY every 30 minutes, then a very careful reconstruction of signal running times (combined of course with the positions of the recieving antennae and the EXACT times the signals were recieved) can reveal information about the heading and position.
That's a good point, if the timestamps have the necessary precision and their clock drift info hasn't been lost by a resync since then. I'd guess that since exact time isn't crucial to the purpose of these messages, though, that they probably don't have very high precision timestamps. :-(
I believe that Rolls-Royce doesn't sell it's engines; it leases them instead. So engine telemetry data from many airlines is transmitted to the engine's owner, which happens to be a central organisation.
(Of course, it is a business, rather than branch of a government, and not the only manufacturer of jet engines).
If they received the data that means the engines managed to communicate somehow. So that tells you the length of time the transmission unit was powered up. Also, using differential signal strength between successive communications one can generate an approximate trajectory (x km from satellite at y time) etc etc. This would surely narrow down the possible locations.
I guess it depends on the data transferred. For an engine you probably have data like altitude, revolutions/second, fuel intake, pressure, etc. To get a status on the engines you probably don't NEED long/lat data. So it might not be in the transmitted bursts.
Maybe there is a way of interpreting the data that tells you when/if the plane turned. e.g. "the chamber pressure in engine 2 is 5% higher than engine 1 ==> the plane was turning left at a rate of 15° per minute". Something crazy like that
I wonder if the necessary transmission origin data wasn't recorded? I bet the fbi is right now going through boeing's network trying to figure that out though. Is it bounced through satellites? You'd think a XXX million dollar plane would have a gps beacon or something though, just like atm machines.
It would be a miracle if it where hijacked and there's even a chance those people are alive.
This blew my mind. Cell phones don't work that far out from range of towers, and they sure as hell don't work at the bottom of the ocean. I heard that those were rumors and that they were false, but if they're true, then that's a major wtf...
It is complete bullshit. The whole story is based around the fact that some people have tried to call their relatives on the plane and have heard the line "ringing" after placing the call. This is exactly what you'd expect to happen when trying to call a phone that's at the bottom of the ocean, as the network will spend some time searching for it and you'll often hear a "ringing" while that happens, but idiots have taken this and transformed it into "the actual cell phones themselves are ringing!"
On a story that is big news like this, but not big enough to dominate coverage: yes. There are so many moving parts that they likely have several reporters on it with the goal of being the first to break the story. But it's not a big enough story that they feel they need 3-4 separate stories on the front page. At last until there is some resolution.
Impossible. The consequence of hiding the truth is an international shame. And do you really think any country launching a missile can go unnoticed? You know that area is under dispute and nearby countries are claiming ownership, meaning they are actively monitoring all military actions. There are satellites watching that area too. No. No.
And why China? I think this is more of an anti-China/China conspiracy. You got Philippines and Vietnam right over there. In fact, Vietnamese navy was the first appeared on the newspaper claiming it had detected a crash before the Chinese.
It's not like the radar systems tracking these things on a day to day basis automatically classify something as a certain type or even size of aircraft.
Even if it were tracked by something, in that area of the world I bet there are quite a few "unscheduled" flights and it perhaps became something of routine. Or some remote radar operator is paid to look the other way on some flights, and mistook this for one of those.
Most likely is that it simply wasn't tracked by anyone who cared, and especially not by anyone who recorded the data.
Can India, China, and Australia be confidently dismissed as destinations, given that they're going to have pretty good air defense radar that would notice a 777 at altitude, and a 777 flying at low altitude wouldn't have nearly as much range?
Sure, you can come up with a solution to any objection, but the problem is failure modes you haven't thought of. The overall point is that any safety measure brings its own dangers along, and you have to be very careful when adding stuff to make sure that you've solved more problems than you've added. It's not at all obvious.
The same happened with the reports of the radar capturing it drastically off-course. First it looked like a sure thing, and then it was eventually completely denied. Perhaps that's just a symptom of such an intensely-analyzed ongoing news story, though.
I do feel a bit sorry for the Malaysian government. They don't get to control what the media prints, but are expected to immediately confirm/deny everything (difficult with the volume of reports they are likely dealing with!), and to some extent get chastised when the media prints stuff that later gets busted.
Yes, though the off-course radar contacts were eventually acknowledged after having been reported, and then completely denied.
From the New York Times: "On Wednesday, after four days of reticence and evasive answers, the Malaysian military acknowledged that it had recorded, but initially ignored, radar signals that could have prompted a mission to intercept and track the missing jetliner. The radar data vastly expanded the area where the plane, which took off early Saturday from Kuala Lumpur for Beijing, might have traveled." http://www.nytimes.com/2014/03/14/world/asia/missing-malaysi...
With that track record it's hard to know whether to credit the Malaysian government's vehement denials.
Special Ops fly NORDO-IFF/SIF off all the time. Check for activity at Oceana NAS and Diego Garcia NS for response. Like the Alitalia DC-9 out of Napoli that got splashed by the Brigade Rosa, no news is not good news.
So we have a plane that flew to another destination without communication and several people with bogus passports on board. Familymembers have reported cellphones that kept 'rining' instead of going directly to voicemail (as they would have if the plane was at rhe bottom of the ocean). Hijacking looks to me the only reasonable explenation.
This statement has to die. It has been confirmed over and over again that the phones aren't on and this is a network thing. Do you really think that if this plane was hijacked the phones would be kept on especially in light of the Snowden/NSA leaks? Tracking cell phones has been common for over a decade now, I'm sure a hijacker would be aware of this and would toss the cell phones into the ocean.
In my experience the network won't ring if it hasn't seen the device in a certain time period. "Straight to voicemail" for that. I'm no expert though, maybe rings are still possible.
But if the network is seeing these phones, it seems to me it'd be pretty simple locate these people by just querying the provider for the tower location. This hasn't happened, so the only conclusion is all the phones were destroyed, disabled, or out of range.
Multiple people who know what they're talking about have confirmed that you don't get the "straight to voicemail" behavior if the phone was last registered on a roaming network rather than its home network. As would be the case for e.g. every single Chinese cell phone that was last turned on in Malaysia.
Is there is some sort of timeout after which it gives up, or a reliable upper bound on the time it takes for a network search, and if so, do you know how long either of those two periods are?
I presume that if you ring a phone, a search is initiated, which would result either the phone being located or the phone being marked as unavailable, and that once the latter had happened you wouldn't get the ringing tone until the phone re-registered on the network.
I only ask because, from memory, the reports that I saw seemed to suggest that people got ringing tones for quite a while, and a cursory search just now indicates phones are still ringing days after the disappearance.
If that was so (unverified assumption), wouldn't that suggest that the network search hadn't yet failed to locate those phones, and that after some period of time that amounts to pretty good evidence that the phones were still connected?
After some link following to  I saw tweet , which suggests that the phones wouldn't have been on the network at all. It doesn't really answer my questions, but I think it rules out the phones as a source of information.
That tweet implies that the first order answer to my question 'how long before a search times out' is 'a long time'.
Instead of turning your phone off, so that it can inform the network that it is going off line, try pulling the battery without warning.
If I turn off my phone gracefully, the network will send incoming calls pretty much straight to voicemail. If my phones battery has died, or the phone dropped off the network for another reason (went camping?), then the network will have your phone ring as it searches for the phone.
No, you will not hear a ringing. The ringing only starts after the phone you are calling has been contacted. When you pull the battery out, the network will keep on searching for your phone and since no phone replies, it will inform you that the phone is out of coverage area.
In my experience cellular phone networks behave very differently in different countries.
In some places I have made calls where I first hear one kind of ring which is then replaced by a second, different kind of ring. A hypothesis is that one network has played a ring tone while it connects to another network, and that the second network plays the other ring tone as the actual phone is ringing. I have even heard three different kinds of tones when making calls to phones that are roaming in foreign countries.
The global phone network is an incredibly heterogeneous spaghetti of different networks built with different gear installed at different times. The internet looks positively homogenous by comparison.
My point is that you shouldn't rush to positively say "No, you will not hear a ringing."
In my experience on US networks, the ring that you hear is completely artificial and the network will have it start before the phone is actually found. That's how you can get a minute or so of ringing followed by the "cannot be found" message.
Seriously, what is the thesis here, that the phones are still 1) intact, 2) charged, 3) on the network, 4) cannot or are not answered, 5) cannot be located? How would those things even make sense, several days after the planes disappearance? That plane sure as shit isn't still flying...
People are identifying something that they consider weird (phones of people on a lost plane ringing) and are using it to justify their pet theories on what happened (involving the phones actually legitimately ringing), without explaining why their pet theory makes anything less weird.
Continuously ringing means the network still thinks the phone's on the network. When you power down your phone it sends a signal to the network saying it's going off. If you just pull the battery or something else where it doesn't send that signal, the network still assumes (maybe only for a time) that the phone is still on but isn't connected to a tower.
But the ringing only starts once the target phone responds to the paging from network, otherwise the network just keeps on searching and after a timeout informs that the target phone is unreachable or out of coverage area.
That's not true. There are cases (e.g. if the phone was last registered on an overseas network because the person was traveling internationally) where the network will generate a "ring" while still searching for the phone.
Even if there is no GPS, it should still be possible to tell whether a number is registered/active on the network. When a phone connects to a network (including roaming) it's location is stored in the operator's HLR (home location register) where it is used to route calls. I'd assume it stores the time the phone was last seen as well.
Is it possible to hack a transponder and make it appear to ATS that a plane is a legitimate craft? Would it be possible to have someone on the ground act as "ATC" and pass off the plane to an unsuspecting ACT so it can enter another countries air space?
It looks like everything either malfunctioned or was intentionally turned off all at once.
A long time ago one of my servers had a very crude monitoring system, it would send me an email every half hour saying "I'm still alive!". Hard to believe that kind of simple thing can't be implemented on a 21st century airliner ( or maybe it is, then forgive my ignorance please). A simple beep beep signal saying "I'm still flying!", every minute or so, with the plane's location as a bonus.
Edit: that said, if the plane starts breaking apart at cruising altitude, it wouldn't help much with finding it...so maybe self-powered transponders in nose, tail, wings, engines etc etc, nicely sealed in "black box" style casings might help. Or maybe they have that already and I know absolutely nothing about modern planes (or planes in general).