Flight MH370

[MahrinSkel]

The satellite transponder they used to triangulate the projected path and that reported its last ping 6 1/2 hours after the machine vanished doesn't work once it's submerged under water or after a crash. Firstly because it's just a satellite transponder that is not powerful enough and because it draws its power from the engine.

That would mean that the plane continued on, on the wrong path, for six hours. If that had been the case wouldn't it have been more likely that the autopilot would have continued on its way to Beijing?

Not necessarily.  The fly-by-wire system has some defaults that would try to keep the plane flying straight and level if all other control inputs were lost (if all control runs got burnt up, for example).  But it wouldn't be making a soft landing, just flying until it ran out of fuel, then into the ocean at several hundred knots.

--Dave

[Merusk]

Flight 447 gives a pretty sobering account of how a cascade of failure from a very minor issue, can cause pilot error that puts an otherwise perfectly OK aircraft into the ground. If the pilots of MH370 didn't trust their instruments for whatever reason, there are a lot of very small mistakes that can have devastating consequences.

And this is why I hate flying. Panicked idiots on the highway can kill me, but I have at least some sort of ability to control my fate and evade them.  Panicked idiots in the sky, I'm dead.

[Evildrider]

[K9]

Flight 447 gives a pretty sobering account of how a cascade of failure from a very minor issue, can cause pilot error that puts an otherwise perfectly OK aircraft into the ground. If the pilots of MH370 didn't trust their instruments for whatever reason, there are a lot of very small mistakes that can have devastating consequences.

And this is why I hate flying. Panicked idiots on the highway can kill me, but I have at least some sort of ability to control my fate and evade them.  Panicked idiots in the sky, I'm dead.

By the same logic, do you also hate taking trains or the metro?

[Chimpy]

Flight 447 gives a pretty sobering account of how a cascade of failure from a very minor issue, can cause pilot error that puts an otherwise perfectly OK aircraft into the ground. If the pilots of MH370 didn't trust their instruments for whatever reason, there are a lot of very small mistakes that can have devastating consequences.

And this is why I hate flying. Panicked idiots on the highway can kill me, but I have at least some sort of ability to control my fate and evade them.  Panicked idiots in the sky, I'm dead.

By the same logic, do you also hate taking trains or the metro?

He lives in one of the many parts of the US where there is no metro and you have to go way out of your way to travel by train.

[Morat20]

Flight 447 gives a pretty sobering account of how a cascade of failure from a very minor issue, can cause pilot error that puts an otherwise perfectly OK aircraft into the ground. If the pilots of MH370 didn't trust their instruments for whatever reason, there are a lot of very small mistakes that can have devastating consequences.

And this is why I hate flying. Panicked idiots on the highway can kill me, but I have at least some sort of ability to control my fate and evade them.  Panicked idiots in the sky, I'm dead.

And for all that, you're still far more likely to die in a car than in a plane.

[Merusk]

More cars on the road than planes. Trains and metro are on rails, so disasters are more of the "guy was drunk" than "airline cuts corners on training. Inexperienced pilot kills 300" or "whoops, took a wrong turn into an obstacle" variety. 

Feel free to keep flying. I hear the experience has only gotten better as time's gone on.  Meanwhile it still costs me less to drive 14 hours than to fly 4 people the same distance, so there's also that.  No, time "saved" isn't included, mainly because I enjoy car trips and despise the dens of humanity that are airports.  So let's count sanity saved as well. My last business flight was supposed to be a 4 hour affair, including the airports.  12 hours later I was beginning to understand serial killer's point of view.

[Morat20]

More cars on the road than planes. Trains and metro are on rails, so disasters are more of the "guy was drunk" than "airline cuts corners on training. Inexperienced pilot kills 300" or "whoops, took a wrong turn into an obstacle" variety. 

Strangely enough, statisticians are very aware of the whole "more cars than planes" bit and thus do things like calculate "fatalities per hour" or "per million miles".

It's not even close. As in "you're an order of magnitude more likely to die" in a car than a plane, even when you've sorted it all out by miles traveled.

Planes are far safer for a couple of reasons -- starting with the fact that pretty much every pilot every is far better trained than any driver outside of NASCAR, that planes themselves have a hell of a lot more safety measures built into them (and their routes) than cars and highways, etc.

For every billion km driven, there are 3 fatalities. For every billion kilometers flown, there are 0.05 fatalities.

[Cheddar]

Infowars is going apeshit.  This and the ukraine thing have made the conspirists heads pop.

[Morat20]

Infowars is going apeshit.  This and the ukraine thing have made the conspirists heads pop.

Conspiracies are fun. And who knows, sometimes the truth even is some weird conspiracy.

[Ghambit]

I'm not watching this thread close enough to address all the questions.  But, back to the "sat-com" and/or ACARS.  There's a big difference between being pingable and transmitting.  A satellite in orbit can ping pretty much ANYTHING on the planet regardless of location (even w/o LOS many times).  If it registers the address as pingable, then the location is 'available.'  It does not mean the location is transmitting.  These big planes have plenty of standby power (not including passive components inside the devices like capacitors, standby batts, etc.).  She could be sitting in a tree canopy or floating on the indian ocean and still show up to the datacenters.

As for AP operation... every plane is different and highly depends on the equipment.   Most modern craft can fly a flight plan w/o input, but typically a pilot would need to 'accept' the course change for the system to allow it.  Even on consumer-grade GPS-coupled APs this is the case.  Maybe that function is bypassable, but not sure.  The navigational intersections you saw the plane theoretically fly are a remnant of the old-school IFR capable radio intersections.  Basically you'd line up 2 or 3 stations and your vectors would put you on those points (if not directed by ATC)... then you'd fly the tables to the next one, and so forth.   Nowadays this is just done virtually with GPS, but the locations still remain.  If MH370 lost GPS they'd pretty much have to use that system to know where they are at night, or old-school RNAV, RDF, etc. (if equipped).  Realize, over the ocean you have NONE of that... just dead reckoning.

Most planes still have a GPIRB, EPIRB, and/or 121.5 ELS in case of emergency (for location-finding).  But, all would need to be manually activated unless submerged.  The GPIRB would also need LOS.  The 121.5 would need a station within range (12 mile radius at 6ft elevation to receiver) listening...  which no one does unless they're coast guard.

It was easy to pin this event as an accident because the route showed an immediate turn towards the nearest land (after the apparent altitude changes).  From there you'd have to make the stretch that the plane was unlandable at night (on land or sea); maybe due to equipment/cockpit failure and the pilot's were biding their time (or unconscious).  Maybe a novice had to commandeer the plane.  Who knows.  It's a certainty the aircraft was acting 'lost' though.  Hell, there are pro. pilots out there (I'm not kidding here) that if you shut off the GPS and/or radios - they're essentially SOL.  Perhaps these pilots just couldnt handle finding their way w/o full instrumentation.

Everyone seems to think the plane is highjacked in central Asia somewhere, but there still are a few experts telling everyone to just 'hold on a minute here' and keep the options open.  1st cause is always pilot error, then breakdown, and then terrorism/hijacking.  The 1st two hypothesis dont just go away because there's strong evidence of the latter.  Also, there are whispers there may have been sabotage causing a pilot error and/or breakdown.

Reminds me of that story about a year ago of that IT company that demonstrated it could take over a plane with nothing more than a laptop and a wi-fi connection.   

[Simond]

Fuck it.. it's aliens.   

Nope.

[calapine]

New information from Malaysian papers. I think it's safe to say now this was not an accident:

MISSING MH370: Final words from jet came after systems shutdown

Authorities have said someone on board the plane first disabled one of its communications systems — the Aircraft and Communications Addressing and Reporting System, or ACARS — about 40 minutes after takeoff.
  
The ACARS equipment sends information about the jet’s engines and other data to the airline.  
  
Around 14 minutes later, the transponder that identifies the plane to commercial radar systems was also shut down. The fact that both systems went dark separately offered strong evidence that the plane’s disappearance was deliberate.

MH370 flew as low as 1,500m to avoid detection

In an exclusive story, the government-backed paper said investigators analysing MH370’s flight data revealed that the 200-tonne, fully laden twinjet descended 1,500m or even lower to evade commercial (secondary) radar coverage after it turned back from its flight path en route to Beijing.

Investigators poring over MH370’s flight data had said the plane had flown low and used “terrain masking” as it flew over the Bay of Bengal and headed north towards land, the NST reported.

Officials, who formed the technical team, were looking into the possibility that whoever was piloting the jet at that time had taken advantage of the busy airways over the Bay of Bengal and stuck to a commercial route to avoid raising the suspicion of those manning primary (military) radars, the paper said.

Source 1 Source 2

Well, shit...   I'd say this is even beyond a "normal" hijacking. Scary...


Edit: No need to thank me for scouring the web to bring you the latest news. It's not like I have anything else to do! (I don't  )

[Hoax]

I love reading threads like this but I also seriously wonder who you people are sometimes and where you find the time/impetus to dig this deep. Keep it up.

[Ghambit]

Only the ACARS went down before the final radio message (there's probably no alarm/indicator that it even happened).  That still does not rule out a serious cascading electrical issue.  As for flying low; that's par for the course if there's a fire.  You need to get down and quickly even if you cant land.

(I'm never going to let this theory go)   

[Khaldun]

I'm just remembering the last time the Internet decided it knew exactly what had happened with a mystery, e.g., the Boston Marathon bombing. Fun's fun and all, but people can be pretty quick to come to strong conclusions based on limited evidence...

[Jeff Kelly]

These big planes have plenty of standby power (not including passive components inside the devices like capacitors, standby batts, etc.).  She could be sitting in a tree canopy or floating on the indian ocean and still show up to the datacenters.

As far as I could find out the only way to get any data off the plane is the ACARS. Every connected system transfers data to the ACARS and the ACARS routes it to the destination via VHF or Inmarsat or other communication systems (depending on what is available on a plane and if it has a connection). Makes sense really, since the transmission power involved to get a message to its destination via VHF or L-Band Satellite is too high for integrated and battery powered transceivers. Also VHF requires an antenna that is between 25 cm and 2,5m long at lambda/4 depending on the band used (VHF is 30 to 300 MHz) and L-Band Transmitters require a 40 cm dish. It's unlikely that a data recording subsystem could transmit anything on its own without going through the plane's transmission system. So in order for the Satellite network to be able to ping the plane and get a reply the whole transmitter system has to still be functional and it has to be powered. Either by backup power or the internal generator.

It also can't transmit while the transmitter (antenna system) is submerged in water. Radio signals are easily isolated by water (that's why the flight data recorder uses sonar or acoustical pings) usually 10 cm to 30 cm of water are enough to completely block any transmissions.

In order for your scenario to work the plane would need to be mostly operational. That's why so many experts still think the plane was in the air for the whole time (at least until fuel ran out) because it would be highly unlikely for those systems to still be active once the plane had crashed and it also seemed unlikely that the plane could have landed anywhere without it being noticed.

So the plane was either still in the air when the last contact was made which probably means that it ran out of fuel and crashed or it was on the ground but mostly intact so that the plane's transmitter was still operational.

Everyone seems to think the plane is highjacked in central Asia somewhere, but there still are a few experts telling everyone to just 'hold on a minute here' and keep the options open.  1st cause is always pilot error, then breakdown, and then terrorism/hijacking.  The 1st two hypothesis dont just go away because there's strong evidence of the latter. 

Usually the most likely explanation is also what really happened. I don't even take issue with that reasoning. It's just that the explanations by experts involved as to why anything else couldn't have happened seems weak. Firstly because the persons involved knew pretty early on that both the transponder and the ACARS have been deliberately shut off before the last 'AOK' transmission was made. This points to other explanations than pilot error or defect as to why the machine is missing. Secondly because the explanations amount to 'the plane couldn't have landed because we would have found it by now if it did' and 'it would require expert knowledge to pull something like this off which the perpetrators likely didn't have'.

Since 9/11 one should be very careful with that line of reasoning because it amounts to nothing but a chauvinistic belief that those brown people aren't smart or educated enough to pull something like this off and a professional pilot would never do this for any reason at all.

The most probably scenario is still that we'll find the plane somewhere, crashed, and that the flight data recorder will show us a scenario that explains everything and that it was simply a chain of events we couldn't even imagine would happen and that we couldn't have anticipated. I don't fault the investigators for looking at every possible angle though, especially since the whole things seems to be suspicious. (The search for a possibly crashed plane is still going on after all even after they've searched the captain's house) I just fault the 'experts' who by and large are quick to dismiss anything out of the ordinary as 'this couldn't have happened, ever'.

[Jeff Kelly]

For me it's a difference if whether you state that 'this is the most likely explanation but we are investigating in all directions', what a professional investigative team would do and 'this is the only explanation and it's unnecessery to investigate anything else because it could have never happened' many 'experts' have been quoted on saying.

[Numtini]

We don't have a lot of mysteries in the world. It's hard to believe in the Yeti when there are hundreds of people climbing Mount Everest. At least right now, while there's obviously been some kind of horrible happening, we have a bona fide "In Search Of" mystery. It's not surprising it's grabbed people's attention and imagination.

[KallDrexx]

The most probably scenario is still that we'll find the plane somewhere, crashed, and that the flight data recorder will show us a scenario that explains everything and that it was simply a chain of events we couldn't even imagine would happen and that we couldn't have anticipated. I don't fault the investigators for looking at every possible angle though, especially since the whole things seems to be suspicious. (The search for a possibly crashed plane is still going on after all even after they've searched the captain's house) I just fault the 'experts' who by and large are quick to dismiss anything out of the ordinary as 'this couldn't have happened, ever'.

I might be wrong but I think the flight recording might be somewhat useless at this point.  We might be able to find out if it was a hijacking or not but I believe the flight recorder only holds 2 hours worth of data, and since it was flying for 4-5 hours past when they went dark I have a feeling we won't ever really know the full story (unless people are actually found alive, which I find highly unlikely).

[IainC]

The voice recorder is a minimum of 30 minutes (NTSB recommendation is 2 hours), the flight data recorder records 17-25 hours of flight data.

[KallDrexx]

The voice recorder is a minimum of 30 minutes (NTSB recommendation is 2 hours), the flight data recorder records 17-25 hours of flight data.

Oh ok, that makes more sense then.

[IainC]

Interesting hypothesis for how MH370 could have used another aircraft to slip through radar undetected into Central Asia.

Starting with a set of facts that have been made available publically and verified over the past few days, I first plotted MH370’s course onto an aviation IFR map which shows the airways and waypoints used to navigate the skies.  I plotted the point where it stopped transmitting ADS-B information at 1721UTC.  I then plotted the Malaysian military radar track from that point towards “VAMPI”, “GIVAL”, and then onward toward “IGREX” on P628 ending with where the plane should be at 1815UTC when military radar lost contact.

Nothing profound there… but then I looked to see what other planes were in the air at 1815UTC and I looked to see exactly where they were positioned in the sky and where they were flying.   The picture started to develop when I discovered that another Boeing 777 was en-route from Singapore over the Andaman Sea.


I investigated further and plotted the exact coordinates of Singapore Airlines flight number 68’s location at 1815UTC onto the aviation map.  I quickly realized that SIA68 was in the immediate vicinity as the missing MH370 flight at precisely the same time.  Moreover, SIA68 was en-route on a heading towards the same IGREX waypoint on airway P628 that the Malaysian military radar had shown MH370 headed towards at precisely the same time.

[...]

So by now, you may have caught on or you may be scratching your head and wondering if I’ve gone insane!  How does SIA68 have anything to do with MH370 disappearing?   Remember the one challenge that is currently making everyone doubt that MH370 actually flew to Turkmenistan, Iran, China, or Kyrgyzstan?  That challenge is the thought that MH370 couldn’t make it through several key airspaces such as India or Afghanistan without being detected by the military. 
It is my belief that MH370 likely flew in the shadow of SIA68 through India and Afghanistan airspace.  As MH370 was flying “dark” without transponder / ADS-B output, SIA68 would have had no knowledge that MH370 was anywhere around and as it entered Indian airspace, it would have shown up as one single blip on the radar with only the transponder information of SIA68 lighting up ATC and military radar screens.

[MahrinSkel]

He's not crazy, what he describes could work.  Even if an operator saw two blips where he 'knew' there was one plane, he'd be likely to dismiss it or report it to maintenance rather than think it was two planes.  Odds are it would never be noticed at all, radar is notorious for artifacts and false echoes, and the resolution isn't all that great unless it's been specifically designed to distinguish planes flying in close formation.

If it's flying that close, it can also 'draft' on the other aircraft and extend the range.

--Dave

[Jeff Kelly]

Even if a RADAR would have shown a sort of 'double-contact' operators might have dismissed it as interference or 'echoes' from flight SIA68 so they might not have suspected that anything was wrong. After all there was a real and scheduled flight showing up on there with a transponder signal.

If that were the case though then the people involved had to have intimate knowledge about all of the technology involved, the airspaces they'd needed to fly over, the flight plans of other planes in the area and so on. I can't imagine even an organized terrorist cell to come up with every bit of information needed.

[IainC]

Most of that stuff is public knowledge, especially if you're a commercial pilot or know enough about commercial aviation to know where to look. All they'd need is to link up with a flight going in the right direction and that airspace is busy, there'd be suitable candidates practically round the clock.

[Jeff Kelly]

I may be wonky on my physics there but wouldn't the fact that a second plane was basically slipstreaming increase the fuel consumption of the plane travelling in front?

[MahrinSkel]

I may be wonky on my physics there but wouldn't the fact that a second plane was basically slipstreaming increase the fuel consumption of the plane travelling in front?

Not unless it was *really* close.  It could get a significant (although sub-optimum) boost at a distance of several hundred meters.  "Heavies" like the 777 throw out such a large wave of air that air traffic control has to keep them miles apart so they don't knock each other around, light aircraft can be flipped outright by it.

--Dave

EDIT: If it was flying 100-200 meters behind, it would be nearly indistinguishable on radar unless someone was looking directly at it with the kind of radar normally only used for missiles or AA guns.

[Goumindong]

I may be wonky on my physics there but wouldn't the fact that a second plane was basically slipstreaming increase the fuel consumption of the plane travelling in front?

No. The plane traveling in front actually gets a reduction in drag because the wake that a plane normally leaves is a low pressure zone which exerts force holding the plane back. Two planes with a good slip would be just like two cars with a good slip. Faster and more fuel efficient than one car. Supposing that you could do it.

That being said, the problem with slipping planes should actually be stalling (and engine air intake). Because the plane in front is pulling air with it as it displaces the plane behind it has effectively reduced air speed. Its possible this effect isn't significant enough in the wing portion to have enough effect. The other issue would be that if you're behind a plane you're flying into its exhaust and not into a good air mix for your engines.

If you wanted to fly close to get radar to ignore you you probably wouldn't fly behind another plane, but beside.

That being said, its entirely more likely that what this information means is that the plane crashed near where we originally saw it disappear and that the other radar contact was actually the other 747 that just happened to intersect with his path and is being confused for the missing plane.

[Ghambit]

Jet wake is the worst and is a serious concern for any pilot no matter how big your plane.  There are rules when dealing with it both on the ground and in the air that ATC and crew have to abide by.  That said, to avoid it they'd have to be right up the ass of the other plane or above it and behind.  Story:  I came into a known 'wakey' area once in a small plane and voiced my concern to the controller; but given the traffic density had nowhere to go - especially when crossing a flighttracked ADIZ.   Sure as shit, got near the departure vector of FLL and wham, whole plane got corkscrewed about 20 degrees left in about 10ms.  Another time I flew underneath an approach vector to MIA and could literally "see" the wake coming (from the burnt JetA); that time I could brace for it and slow down.

These big planes have plenty of standby power (not including passive components inside the devices like capacitors, standby batts, etc.).  She could be sitting in a tree canopy or floating on the indian ocean and still show up to the datacenters.

As far as I could find out the only way to get any data off the plane is the ACARS. Every connected system transfers data to the ACARS and the ACARS routes it to the destination via VHF or Inmarsat or other communication systems (depending on what is available on a plane and if it has a connection). Makes sense really, since the transmission power involved to get a message to its destination via VHF or L-Band Satellite is too high for integrated and battery powered transceivers. Also VHF requires an antenna that is between 25 cm and 2,5m long at lambda/4 depending on the band used (VHF is 30 to 300 MHz) and L-Band Transmitters require a 40 cm dish. It's unlikely that a data recording subsystem could transmit anything on its own without going through the plane's transmission system. So in order for the Satellite network to be able to ping the plane and get a reply the whole transmitter system has to still be functional and it has to be powered. Either by backup power or the internal generator.

It also can't transmit while the transmitter (antenna system) is submerged in water. Radio signals are easily isolated by water (that's why the flight data recorder uses sonar or acoustical pings) usually 10 cm to 30 cm of water are enough to completely block any transmissions.

In order for your scenario to work the plane would need to be mostly operational. That's why so many experts still think the plane was in the air for the whole time (at least until fuel ran out) because it would be highly unlikely for those systems to still be active once the plane had crashed and it also seemed unlikely that the plane could have landed anywhere without it being noticed.

So the plane was either still in the air when the last contact was made which probably means that it ran out of fuel and crashed or it was on the ground but mostly intact so that the plane's transmitter was still operational.

Everyone seems to think the plane is highjacked in central Asia somewhere, but there still are a few experts telling everyone to just 'hold on a minute here' and keep the options open.  1st cause is always pilot error, then breakdown, and then terrorism/hijacking.  The 1st two hypothesis dont just go away because there's strong evidence of the latter. 

Usually the most likely explanation is also what really happened. I don't even take issue with that reasoning. It's just that the explanations by experts involved as to why anything else couldn't have happened seems weak. Firstly because the persons involved knew pretty early on that both the transponder and the ACARS have been deliberately shut off before the last 'AOK' transmission was made. This points to other explanations than pilot error or defect as to why the machine is missing. Secondly because the explanations amount to 'the plane couldn't have landed because we would have found it by now if it did' and 'it would require expert knowledge to pull something like this off which the perpetrators likely didn't have'.

Since 9/11 one should be very careful with that line of reasoning because it amounts to nothing but a chauvinistic belief that those brown people aren't smart or educated enough to pull something like this off and a professional pilot would never do this for any reason at all.

The most probably scenario is still that we'll find the plane somewhere, crashed, and that the flight data recorder will show us a scenario that explains everything and that it was simply a chain of events we couldn't even imagine would happen and that we couldn't have anticipated. I don't fault the investigators for looking at every possible angle though, especially since the whole things seems to be suspicious. (The search for a possibly crashed plane is still going on after all even after they've searched the captain's house) I just fault the 'experts' who by and large are quick to dismiss anything out of the ordinary as 'this couldn't have happened, ever'.

Not a disagreement but I will clarify again.  The ACARS wasnt transmitting anything (already established), plane operational or not.  All it was doing was passive 'wake on lan' type listening.  It's no different then a powered-down smart TV or a computer in sleep mode.  You can still ping the equipment and get a few bits response, but that doesn't mean said equipment is fully "on" or even operational.  All those systems could be shut down and as long as the receiver is functional w/millivolts available to the volatile RAM, still be pingable.   To give a frame of reference; you can buy a cigarette pack sized 'pinger' that'll work on standby for 4 years and transmit actively for minimally 2 days to an orbiting constellation.

Also realize, the only reason this data is even being looked at is because there are no other avenues to go down.  Typically one would not need to sift through acars triangulation even in the case of something like AirFrance (who had full acars all the way to impact).  But, take that EE-room and set it afire??  With the plane being lost?  There's not much else you can do.

Not saying to discount hijacking at all (it's popularly the most valid theory), but seriously...  electrical/mechanical failure with a subsequent crash-landing is still very much an option especially in these newer planes (777 is electrically 'notorious' btw).  You have some of the best pilots in the world on TV saying the same thing... especially with the apparent lack of any cell phone data, not even an inflight internet usage.  If the plane was hijacked, it's highly unlikely not a single passenger got any data out - especially a plane full of Freescale engineers (hell, they probably designed many of the systems in the plane).

[Lantyssa]

So you're suggesting the engineers  had the know-how to hijack this specific plane?  I t was an inside job.

[Jeff Kelly]

The reason that those cigerette-pack sized pingers work for four years on standby is that they do nothing else and have been designed exactly for that application.

The main parameters that determine power use of a transmitter or more exactly - how much power does a certain transmitter need to still be able to be received by a certain receiver at a distance of X - is:

1. range
2. bandwidth
3. receiver sensitivity (kind of dependent on 1. and 2.)

If all you need is a link that transmits virtually no data (a ping is essentially just that) and can therefore use a very narrow-band transceiver (a few bit/s) then the amount of energy you need to transmit over a certain range can be really low. If you have to do the same with a wideband-transmitter you also use to transmit large datagrams your power requirements will be much higher.

I've designed transmitter systems that cover a distance of 1000 miles and work for yeras on a single coin cell. Those transceivers are very narrow band though and would only be able to transmit a few bytes/s. It would not be possible though if the transmitter was capable of for example transmitting 100 kBit/s.

At a certain bandwidth level and range (a few kBit/s at a range of miles) the power required to transmit can no longer come from a simple small battery, like the ones used in those small transmitter devices. The receiver would draw more power than the chemical reaction in those batteries can deliver. That limit is reached even sooner when you need batteries that work in hostile environments. (-80°C at 30,000 feet or inside an engine compartment at +600°C) because batteries that survive that environment deliver even less power.

You'd need a few watts of transmit power to reach an Iridium or Inmarsat Satellite in low earth orbit if you needed to do that with the sort of L-Band Transmitter you'd also use to transmit ACARS datagrams, even if all you wanted to transmit is a reply to a ping (and it has to reply otherwise we wouldn't know that the transmitter was active). That's why those systems only transmit when mains power is available, that's also why you can turn them off to conserve power. If they run on backup power the batteries involved are usually much more voluminous than AA-Batteries, more like car batteries.

[Jeff Kelly]

The reason that laptop and mobile phone batteries are so sophisticated is not only because of the capacity (several amp-hours) but also because of the high power draw (100 mA of current and more). That's also why your car abttery is such a huge thing compared to other types of rechargables (up to 30 amps of current drawn at engine start)

A normal battery would just lead to a brown out of the device or the battery would get too hot and explode.

[Quinton]

Thought this was an interesting point of view: https://plus.google.com/106271056358366282907/posts/GoeVjHJaGBz

MH370  A different point of view. Pulau Langkawi 13,000 runway.

A lot of speculation about MH370. Terrorism, hijack, meteors. I cannot believe the analysis on CNN - almost disturbing. I tend to look for a more simple explanation of this event.
 
Loaded 777 departs midnight from Kuala to Beijing. Hot night. Heavy aircraft.  About an hour out across the gulf towards Vietnam the plane goes dark meaning the transponder goes off and secondary radar tracking goes off.
 
Two days later we hear of reports that Malaysian military radar (which is a primary radar meaning the plane is being tracked by reflection rather than by transponder interrogation response) has tracked the plane on a southwesterly course back across the Malay Peninsula into the straits of Malacca.
 
When I heard this I immediately brought up Google Earth and I searched for airports in proximity to the track towards southwest.
 
The left turn is the key here. This was a very experienced senior Captain with 18,000 hours. Maybe some of the younger pilots interviewed on CNN didn't pick up on this left turn. We old pilots were always drilled to always know the closest airport of safe harbor while in cruise. Airports behind us, airports abeam us and airports ahead of us. Always in our head. Always. Because if something happens you don't want to be thinking what are you going to do - you already know what you are going to do. Instinctively when I saw that left turn with a direct heading I knew he was heading for an airport. Actually he was taking a direct route to Palau Langkawi a 13,000 foot strip with an approach over water at night with no obstacles. He did not turn back to Kuala  Lampur because he knew he had 8,000 foot ridges to cross. He knew the terrain was friendlier towards Langkawi and also a shorter distance.
 
Take a look on Google Earth at this airport. This pilot did all the right things. He was confronted by some major event onboard that made him make that immediate turn back to the closest safe airport.
For me the loss of transponders and communications makes perfect sense if a fire. There was most likely a fire or electrical fire. In the case of fire the first response if to pull all the main busses and restore circuits one by one until you have isolated the bad one.

If they pulled the busses the plane indeed would go silent. It was probably a serious event and they simply were occupied with controlling the plane and trying to fight the fire. Aviate, Navigate and lastly communicate. There are two types of fires. Electrical might not be as fast and furious and there might or might not be incapacitating smoke. However there is the possibility given the timeline that perhaps there was an overheat on one of the front landing gear tires and it blew on takeoff and started slowly burning. Yes this happens with underinflated tires. Remember heavy plane, hot night, sea level, long run takeoff. There was a well known accident in Nigeria of a DC8 that had a landing gear fire on takeoff. A tire fire once going would produce horrific incapacitating smoke. Yes, pilots have access to oxygen masks but this is a no no with fire. Most have access to a smoke hood with a filter but this will only last for a few minutes depending on the smoke level. (I used to carry one of my own in a flight bag and I still carry one in my briefcase today when I fly).
 
What I think happened is that they were overcome by smoke and the plane just continued on  the heading probably on George (autopilot) until either fuel exhaustion or fire destroyed the control surfaces and it crashed. I said four days ago you will find it along that route - looking elsewhere was pointless. 
 
This pilot, as I say, was a hero struggling with an impossible situation trying to get that plane to Langkawi. No doubt in my mind. That's the reason for the turn and direct route. A hijack would not have made that deliberate left turn with a direct heading for Langkawi. It would probably have weaved around a bit until the hijackers decided on where they were taking it.
 
Surprisingly none of the reporters , officials, other pilots interviewed have looked at this from the pilot's viewpoint. If something went wrong where would he go? Thanks to Google earth I spotted Langkawi in about 30 seconds, zoomed in and saw how long the runway was and I just instinctively knew this pilot knew this airport. He had probably flown there many times. I guess we will eventually find out when you help me spread this theory on the net and some reporters finally take a look on Google earth and put 2 and 2 together. Also a look at the age and number of cycles on those nose tires might give us a good clue too.   
 
Fire in an aircraft demands one thing - you get the machine on the ground as soon as possible. There are two well remembered experiences in my memory. The AirCanada DC9 which landed I believe in Columbus Ohio in the eighties. That pilot delayed descent and bypassed several airports.   He didn't instinctively know the closest airports. He got it on the ground eventually but lost 30 odd souls.   In the 1998 crash of Swissair DC-10 off Nova Scotia was another example of heroic pilots. They were 15 minutes out of Halifax but the fire simply  overcame them and they had to ditch in the ocean. Just ran out of time. That fire incidentally started when the aircraft was about an hour out of Kennedy. Guess what the transponders and communications were shut off as they pulled the busses.
 
Get on Google Earth and type in Pulau Langkawi  and then look at it in relation to the radar track heading. 2+2=4  That for me is the  simple explanation why it turned and headed  in that direction.

Smart pilot. Just didn't have the time.

[lamaros]

People love a conspiracy theory, but there is only one reason to assume such a thing in this case, that there were two people traveling on stolen passports. I would love to see how common that is though, perhaps it's not really that remarkable.

Only an accident makes sense.