Missing Malaysian Aircraft – is it possible…

Maybe this was mentioned already but … does the CVR have more than about the last 30 mins on it? If so, then I suppose it may well have nothing more interesting than the bonkers suicidal pilot humming to himself as he heads into oblivion … ?

Not very much. Not given that even pilots sometimes need to use the toilet and the existence of anti-hijack cockpit doors.

but i thought the cockpit was on a code that the copilot at least also knows

robbespierre – Member
The plane flew back over Malaysia, so you would expect some signal to be available?

no signal at that height apparently

Apparently the CVR on 777s runs for 2 hours rather than 30 mins – unlikely to be of any more help though. Given modern technology there appears to be no reason why it wouldn’t be possible to make one with a 24hr+ duration which would always capture the whole of a flight (it might be useful to know what was said for the whole flight even for more mundane crashes), but the technology actually in use dates to when the plane was designed, presumably due to the difficulty and expense of certifying stuff like this on aircraft. Not that it’s likely to help at all if it can’t be found.

I thought we’d done that one on this thread? Not much mobile signal at 30k ft when travelling at 600mph inside a metal box, even assuming you’re anywhere near mobile coverage.

ha ha ninja edit.

Indeed – point still stands though.

too late to edit mine..

robbespierre » If it was a hijack, by the pilot or a passenger, and the other cabin staff or passengers knew about it, wouldn’t they have used their mobile phones to send messages? The plane flew back over Malaysia, so you would expect some signal to be available?

I thought we’d done that one on this thread? Not much mobile signal at 30k ft when travelling at 600mph inside a metal box, even assuming you’re anywhere near mobile coverage.

Sorry. But there are 18 pages of this thread and I do have a job 🙂

I know aircraft engineeers and cabin crew, they all confirm that there is a way to open the door.
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Really? Presumably not one that any potential hijackers know? Because security through obscurity is very highly rated.

The fact remains that the door is designed to be impossible to break down, so presumably you only have to disable the mechanism by which the door can be opened from the outside if you so inclined.

No reason why a mobile phone wouldn’t work on a plane. 40,000ft is only 7 miles so well within the range capability of a mobile phone, so as long as you’re flying over a network a mobile phone would work fine.

There cannot be a way to open the door from the outside, not while the aircraft is flying at least. Cabin crew always knock on the door for the pilots to open it from within when providing refreshments. They don’t open the door themselves. Also in the Helios air crash the steward who woke up had to break the door down to get into the cockpit. It completely defeats the object for one of the cabin crew to have access. You may as well take the door off altogether.

Please stop talking about how to get past cockpit doors before somebody says something really stupid.

Mobiles don’t work on aeroplanes at normal cruising altitudes.

Yes they do.

Film 4 just now is one of our aircraft is missing and movie mix showing termination point also about a missing aircraft.
:0

Except the radiation pattern of the masts doesn’t point upwards, as that would waste a lot of power. Also as mentioned above there is the issue of speed creating doppler and sitting in a nice shielding metal tube.

There cannot be a way to open the door from the outside, not while the aircraft is flying at least. Cabin crew always knock on the door for the pilots to open it from within when providing refreshments. They don’t open the door themselves. Also in the Helios air crash the steward who woke up had to break the door down to get into the cockpit. It completely defeats the object for one of the cabin crew to have access. You may as well take the door off altogether.

There was an interview in the Guardian the other day with a commercial pilot and stewardess. Both said you can open the doors from the outside. Post 9/11 they put in armoured doors which could only be opened from the inside. But when they realised this might be a problem (Helios, etc) they provided access via keypad. The pilot can override this, but there is still an emergency procedure available to open the door.

No reason why a mobile phone wouldn’t work on a plane. 40,000ft is only 7 miles so well within the range capability of a mobile phone, so as long as you’re flying over a network a mobile phone would work fine.

Apparently a mobile should be capable of reaching a mast up to 45 miles away, if it’s CDMA, 22 if it’s GSM, but of course, there has to be a mast of an appropriate network within those distances, and once the plane’s left the coastline well behind, that’s it, no towers at sea.

Except the radiation pattern of the masts doesn’t point upwards, as that would waste a lot of power. Also as mentioned above there is the issue of speed creating doppler and sitting in a nice shielding metal tube.

A plane fuselage is not that attenuating e.g. you can easily make and receive calls whilst taxiing etc. Obviously you’re right near a mast as they place them as close as possible to runways to try and get lucrative roaming traffic, as the older GSM phones used to roam to the strongest signal, hence all the operators competed to have the strongest signal by the runways.

UMTS (3G) can only cope with Doppler shifts up to about 250 km/hr which rules out cruising speed, but means when planes stack, you could make a call etc.

Apparently a mobile should be capable of reaching a mast up to 45 miles away, if it’s CDMA, 22 if it’s GSM

That’s the limit of delay compensation rather than link budget. As mentioned before, mobile phone base station antennas radiate outwards and specifically not upwards (to maximise range) which means the link budget in the vertical range is much more limited, hence the range is much more limited.

Left hand side is elevation pattern:

the pilot wife left him the day before . they had separated for a while but were leaving under same roof .

Regardless of the mechanics of whether a mobile phone would or wouldn’t work, the fact is that it was a night flight. By the time the flight went offline, I’m willing to bet that most passengers were asleep and won’t have even noticed it going off course. When they woke up (if they ever did, assuming the aircraft was still pressurised), the plane will have been way out over the Indian Ocean and out of range of any signal at all.

A plane fuselage is not that attenuating e.g. you can easily make and receive calls whilst taxiing etc. Obviously you’re right near a mast as they place them as close as possible to runways to try and get lucrative roaming traffic, as the older GSM phones used to roam to the strongest signal, hence all the operators competed to have the strongest signal by the runways.

Given the nearby base stations you mention, the fuselage could attenuate quite a lot and you still get a decent signal. I’d be surprised if there wasn’t quite significant attenuation. It’s just one small part though – the doppler and the radiation pattern of the base stations are more significant.

If the “facts” given out to the public so far are indeed true then one would have to assume pilot involvement for the reasons already discussed in these 18 pages.

Where are we up to with motivation though? Are there any theories besides “highly disturbed and suicidal”?

Was the possible lucrative patents gain by Lord Rothschild given any serious consideration (I can’t find the page, sorry) or written off?

By the time the flight went offline, I’m willing to bet that most passengers were asleep and won’t have even noticed it going off course

TBH, when you’re on a long flight do you really have any idea where you are, even when you’re over land?

Given the nearby base stations you mention, the fuselage could attenuate quite a lot and you still get a decent signal. I’d be surprised if there wasn’t quite significant attenuation. It’s just one small part though – the doppler and the radiation pattern of the base stations are more significant.

The Doppler mean it wouldn’t work period much above 250 km/hr as the modem wouldn’t achieve frequency lock, regardless of the signal strength.

If you’re interested there are UMTS system which work for plane telemetry eg http://www.triteq.com/media/25541/transmitting_live_aircraft_security_data_by_3g.pdf

They have to use extra HW to account for the excessive Doppler.

Was the possible lucrative patents gain by Lord Rothschild given any serious consideration (I can’t find the page, sorry) or written off?

Sounds like usual anti-Semitic anti-reptilian bollocks. I’m a lowly office monkey who produces nothing of value and all my data is backed up twice.

Fair enough. So no other thoughts (besides deranged), however outrageous, as to possible motivation for a pilot to do what most seem to think happened?

Apparently it was orchestrated by the Israelis, as part of a plan to fabricate a lookalike plane and fly it into the Al Aqsa mosque.

According to a man on the internet.

Apparently if the latest estiamtes are correct, then the other “debris” sightings (that were dissed by a bloke on the internet, much to the chagrin of some other experts) are false..

Tweets by WrightUps

The only place I’m aware of that will allow mobile phone calls at cruise altitudes and speeds is roughly a 50 mile radius NW of Athens, due I imagine to the topography and location of the masts.

Over the sea? No chance.

Toys, I don’t think that anyone here is saying that the satellite images were positively identified as being 777 debris, or indeed that they were conclusively debris at all. The images were of objects which merited further investigation. What we are saying is that some bloke browsing on the internet could not realistically discredit the images, especially when other people, who are presumuably trained in the business of photographic interpretation, have already looked at them.

This thread is more interesting than the main media outlet coverage.

Probably because we have more people with scientific understanding on here than all the journos on all the media put together.

Regarding the debris, the chances are that the vast majority of sightings are going to be false leads. Hence those dismissing them based on just what they can see on the internet are going to be proved right. That is until some real debris turns up. It’s all very self-fulfilling based on the odds involved.

Reading The Times at lunch, there was a news piece in there saying that some UK based firm of lawyers was “advising” the relatives that the most likely cause was an electrical fire or short causing the crew & passengers to become incapacitated, the aircraft continued flying as a ghost plane until it ran out of fuel and crashed.

They;’re saying this based on having worked on some other aviation cases and because if it’s mechanical failure rather than deliberate crew sabotage, it allows them to sue Malaysian Airlines… So no motive there then… 😉

I’m only ribbing anyway, lets face it we don’t have a clue, neither do they…

Incidentally, how do we know it climbed up FL430 (or whatever) after the transponder switched off? Was this some sort of height finding primary radar or information from the a/c itself.

I’m starting to think more and more that they are never going to find the plane. If its down that 4,000metre ridge for instance. How will they ever A). Locate the backbox and B). Recover? Once its signals gone- it could be ANYWHERE.

So for now for eternity the Pilots names will be blackened (well if the manufacturers etc are facing uncertainty they’ll point to pilot error/interface wont they as ‘probable’ to protect their future sales opportunities.).

I have sent texts and emails from an aircraft when flying over Europe. OK it was at maybe 25k ft and not 40k ft but I sent and received texts perfectly fine and had a full signal. Also people were making voice calls and texting from the aircraft that crashed when the passengers overcame the hijackers on 9/11, so it is technically possible to use your mobile on an aircraft if you are overflying a mobile network. Also the aricraft was not equipped with an aero-mobile system. Radio masts do not ‘point’ in any direction. Radio waves radiate in all directions.

I still find it hard to believe that cabin crew can access the cockpit door in-flight despite what the Times says. You can’t believe everything you read in the papers. Some airlines may have introduced rules, but it was not mandated as a result of the Helios event as far as i’m aware. It seems utterly pointless to have an armoured door if someone on the passenger side knows the code! I don’t think even BA cabin crew are paid enough to sacrifice their lives.

Once its signals gone- it could be ANYWHERE.

I did hear something about possibly recover via passive scanning. I would imagine/hope that it is fitted with something similar to the RECCO system used in ski/snow wear which reflects an incoming signal without requiring on-board power.

Radio masts do not ‘point’ in any direction. Radio waves radiate in all directions.

Hmmm.. They do look quite directional!

I’m fairly sure that’s based on primary radar coverage. Military radar does often have some height capability (vertical arrays, or nodding), but we’re not being told what it uses or how accurate it is, and I’d imagine we’re unlikely to be told. Personally I’d take the accuracy of that height with a pinch of salt – could easily be out by 5-10,000ft. Useful info to know that it might have happened, but I wouldn’t be placing to much reliance on formulating a scenario based on that (or ruling anything out because of it).

You weren’t maybe a bit lower than that, and flying a bit slower (as is often the case with European flights)? Or maybe an onboard transponder?

Also people were making voice calls and texting from the aircraft that crashed when the passengers overcame the hijackers on 9/11

That aircraft certainly was a lot lower and slower.

Radio masts do not ‘point’ in any direction. Radio waves radiate in all directions.

Radio antennas on masts very certainly do “point” and radio waves only propagate in all directions from an omnidirectional antenna. How do you imagine radar works if it’s not possible to direct radio waves? Why do you think you have to point a satellite dish? I’ll claim some authority on this issue as I used to work with radio systems.