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Terrific! An aircraft with a propensity for catching fire and with faulty fire-extinguishers. They are still flying, I was tracking a Thompson one from Cancun to East Midlands this morning
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The BBC doesn't actually say what the problem is, beyond a "wiring issue".
It's somewhat more serious than that. On three aircraft they've discovered that the fire extinguishers for the left engine were cross-wired with those for the right.
To make that clear, firing the extinguisher for the left engine will actually discharge it into the right hand side, and vice-versa. Apart from the fact that you still have a inextinguishable fire, I'm not entirely sure what the consequences are of discharging a fire extinguisher into a running engine*, which, of course, contains a perfectly normal fire in the middle.
Lithium batteries are a law unto themselves. Wiring the bleedin' fire extinguishers back to front is entirely different and raises serious questions about Boeing's quality control system.
* I don't think anyone's ever tested this particular scenario. In theory the agent should only disperse around the cowling and pylon, but who knows?
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Wasn't there a similar problem with the 737-300 - the one that crashedat East Midlands - weren't the extinguisher switches cross wired on that ? Disturbihng if this has happened on a Boeing jet again.
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I read recently that there was a potentially huge problem with aircraft portable fire extinguishers being fraudulently filled with CO2 because it was a fraction of the cost of the Halon that they should be filled with.
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Must have been a while ago; Halon has been banned.
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>> Must have been a while ago; Halon has been banned.
>>
No, recently. It has to be recycled for aircraft cabin use as it is no longer produced. The reason it is expensive.
A Google gives suppliers.
Last edited by: Old Navy on Thu 15 Aug 13 at 11:10
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ISTR recall that there was cockpit confusion as to which one of the two engines had failed. Pilot thought No2 had failed, pax and crew reported sparks etc from No1. Pilot descended with engines at idle and shut down the one he thought was failed (2) and when he tried to slow the descent by opening the damaged one (1) it failed and the aircraft crashed short of the runway, on the M1
182 page report here! www.aaib.gov.uk/cms_resources.cfm?file=/dft_avsafety_pdf_502831.pdf
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Ah yes just read the executive summary on Wiki !
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There have been problems with these type of batteries used in various brands of laptops for six or seven years; some laptops caught fire.
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I heard tell many some years ago by a Contract pilot that it was preferable not to board anything Boeing.
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>> I heard tell many some years ago by a Contract pilot that it was preferable
>> not to board anything Boeing.
I assume then you have never flown anywhere?
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The top half of sites like Flight Global has a lot of good information on the industry. The bottom half is full of ignorant rubbish like MD's quote above, the most hackneyed being the moronic "If it ain't Boeing, I ain't going". Ignore.
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Beastly manners too. I only repeated what the Pilot said so wind yer neck in.
And to Zeddo the same. I never said I have heeded his words.
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Hardly. I mentioned that you were quoting that view, not espousing it yourself. And it is rubbish. Neck remains unwound-in.
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I wonder how easy it would be to actually avoid Boeing planes? I would imagine it is possible to fly to most places in the world via an Airbus or although not on a direct flight.
Of course people on the other side of the pond say never board a Scarebus. I don't like flying so I do tend to avoid it but I think if I had a choice I would rather fly on an Airbus, although I would be happy with a 777 or the A330/A340 now that the probe issues which caused the Air Chance disaster has been fixed.
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I cannot see that who made the plane matters a damn.
Now as to how it is serviced or flown on the other hand....................
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>> I cannot see that who made the plane matters a damn.
>>
>> Now as to how it is serviced or flown on the other hand....................
I would avoid Garuda. So bad it, it was banned from flying into EU airspace.
en.wikipedia.org/wiki/Garuda_Indonesia_Flight_200
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>> I would avoid Garuda. So bad it, it was banned from flying into EU airspace.
>>
I flew one leg of a round the world multi flight holiday with Garuda 18 years ago, it was Bali to Kuala Lumpur, I must be one of the lucky ones. :-)
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"I would avoid Garuda. So bad it, it was banned from flying into EU airspace. "
A few hundred deaths is statistically just background noise. Nothing to worry about.
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>> "I would avoid Garuda. So bad it, it was banned from flying into EU airspace.
>> "
>>
>> A few hundred deaths is statistically just background noise. Nothing to worry about.
You wouldn't say that if it crashed into your garden fence.
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>> I would be happy with a 777 or the A330/A340 now that the probe issues which caused the Air Chance disaster
All is written Sheikha. All air has a chance element.
I've been in some fairly shaky old crates, but really they're all shaky old crates to me. Look out of the window. You can see them shaking.
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They're designed to shake, AC - well, to flex, anyway. If they were built rigid they'd be too heavy to get off the ground. Look at an A340 at rest and you'll see that the outer engines are tilted at a different angle from the inner pair. Once the wing is loaded with the weight of the aircraft, it twists enough to make the engines parallel again.
I've flown in all the major types except, curiously, the 777, and have no fear of any of them. NoF is right that maintenance matters, but choose a major European, North American or East Asian airline and there are no worries there either. The biggest hazard, whatever you fly in, is the car journey to or from the airport.
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Being scared of flying in a Boeing could find you stranded abroad if the return flight is a "B" plane. If you are used to flying in helicopters even cattle class in a major western or middle eastern company airliner is luxury, on second thoughts maybe not some American airlines. :-)
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Rumour has it that the Ethiopian Dreamliner is a technical write-off, but Boeing are buying it back from the airline and using it for testing. This avoids the unfortunate statistic of a hull loss within the first year of service.
So theyre sticking a plaster over the hole and ferrying it back to Seattle at some point.
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If that's true then any Dreamliner getting damage to the fuselage might be a write-off. Not surprising considering how it is made but not what I'd have expected for a modern plane. But how do you fix a big hole like that and not compromise the aircraft?
Might be worth them buying it to practice fixing one for real.
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>> They're designed to shake,
You don't say!
Of course I am aware WDB... I was just hoping to terrify the Sheikh into going by car next time. But it's true I'm not that keen on flying, have been in some dodgy old Ilyushins and have the same touching faith as everyone else in the superiority of European maintenance schedules and quality.
Fingers crossed eh?
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There was a program about air crashes on BBC4 last night. They showed a wing being tested for load. I thing it was at Boeing. It was loaded to exceed its design strength until it broke. 154% was the load when it failed and the wing was curved upward at what looked liked 45 degrees. The failure when it came was impressive.
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>> I wonder how easy it would be to actually avoid Boeing planes? I would imagine
>> it is possible to fly to most places in the world via an Airbus or
>> although not on a direct flight.
>>
>> Of course people on the other side of the pond say never board a Scarebus.
>> I don't like flying so I do tend to avoid it but I think if
>> I had a choice I would rather fly on an Airbus, although I would be
>> happy with a 777 or the A330/A340 now that the probe issues which caused the
>> Air Chance disaster has been fixed.
>>
>>
Scarebus? Always preferred the phrase "Electric Death Jet" myself.
The probe issues are still there. Sufficient supercooled rain can overpower any heating system. Loss of air data is not particularly uncommon, and is something that is practised on a fairly regular basis in the simulator.
Having said that, the A320 series now comes with a backup speed scale driven directly by data from the angle of attack probes. It's designed for small minds (ie, mine) and simply has a green band that you keep the speed in, and red bits above and below, helpfully marked "FAST" and "SLOW".
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Not a tortoise and a hare that I saw on a tractor dash once ? :-)
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You really should ease up on that seaweed eating RP. Some of that stuff is well trippy.
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A350 test video - the interesting bit is around 1:20 when you see the wing flex
youtu.be/B74_w3Ar9nI
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My nasty, noisy petrol rotary lawnmower has a tortoise and a hare on its crude throttle control. It's Australian-made, but maybe I've got the international edition and they save the wombat and the kangaroo for the domestic market.
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I assume that as it only affects the GE engined fleet then this is more of an engine manufacturer issue rather than a direct Boeing issue, however, people will still see it as a 787 issue whatever the cause.
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I thought they tested these things.
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They do but some of these incidents are outside what the tests cover. Some can be unusally combinations of factors. Ice build up will be something looked at a lot more closely, issues are on the rise.
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Looks to be wholly an engine issue as it affects latest version of 747 with the same GE engines.
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GE are not the only maker who have experienced engine ice issues, i.e. near crash at heathrow with RR engines.
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Was that specific to the Rollers? Ice in the filters wasn't it? I can't remember anything these days:(
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Ice sat on top of the fuel filters on the inlet side. Caused by very cold temperature and little fuel flow in the cruise.Changed the design of the filter and I think the heat eexchanger.
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>> Ice sat on top of the fuel filters on the inlet side. Caused by very
>> cold temperature and little fuel flow in the cruise.Changed the design of the filter and
>> I think the heat eexchanger.
And changes to the flight profile,
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>> I assume that as it only affects the GE engined fleet then this is more
>> of an engine manufacturer issue
>>
news.yahoo.com/boeing-ge-notify-airlines-engine-icing-risk-747-094401072--sector.html
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Aviation Safety Network reporting another Dreamliner fire...Air India aircraft.
Last edited by: R.P. on Tue 24 Dec 13 at 13:49
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Looks like a couple of issues again.
Air India noticed sparks from the brakes upon landing and Norweigian air have an aircraft grounded pending receiving spares
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The brakes on the main bogies of large passenger jets are absolutely amazing, huge multiple carbon fibre discs, immensely expensive, which are self-consuming and wear out very rapidly. No wonder they sometimes emit the odd spark.
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Missing 777 is far greater problem now.
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The sudden disappearance of an aircraft with no radio communication, implies, to me at least, a catastrophic structural failure and I think there will be some connection to the two passengers travelling on passports that did not belong to them.
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Current suggestions are that the plane was turning back.
It also seems that the people with stolen passports had booked onward flights to Europe.
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It is also stated that the aircraft was damaged, and repaired, about 2 years ago. A faulty repair on a 747, in the past, led to this. "Japan Airlines Flight 123 was a scheduled domestic Japan Airlines passenger flight from Haneda Airport (Tokyo International Airport) to Osaka International Airport, Japan. On Monday, August 12, 1985, a Boeing 747SR operating this route suffered mechanical failures 12 minutes into the flight and, 32 minutes later, crashed into two ridges of Mount Takamagahara in Ueno, Gunma Prefecture, 100 kilometres (62 miles) from Tokyo. The crash site was on Osutaka Ridge, near Mount Osutaka. All 15 crew members and 505 of the 509 passengers on board died, resulting in a total of 520 deaths and 4 survivors."
A faulty repair to the rear pressure bulkhead, damaged in a "Tail Scrape/ over rotation" incident caused the rear bulkhead to fail with consequent damage to flying controls and a crash.
Last edited by: Meldrew on Sun 9 Mar 14 at 15:50
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>> Current suggestions are that the plane was turning back.
One needs to take that with a pinch of salt, planes don't "turn back" without some prior radio contact with a controller or head office or both.
>> It also seems that the people with stolen passports had booked onward flights to Europe.
Stolen or fake passports are often used by criminal elements in the far/mid east to enter the airline system. Does not immediately mean terrorists.
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If it were terrorist related surely one would expect some sort of claim of responsibility within a fairly short time-scale?
Radar returns suggesting a turn back my also be symptomatic of a loss of control.
Whatever the cause location/recovery of wreckage is going to be a big job, similar to that for the Air France A340 lost off South America.
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>>>Whatever the cause location/recovery of wreckage is going to be a big job, similar to that for the Air France A340 lost off South America. <<<
I think that you will find that much of the area under search is relatively shallow and diveable.
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Bit smaller than the south atlantic as well. It was nothing short of a miracle they recovered that Air Chance black box.
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>> If it were terrorist related surely one would expect some sort of claim of responsibility
Not necessarily I think. Lockerbie and the DC10 out of Chad that came down in Niger were not claimed I seem to remember.
These sudden disappearances are more often caused by bombs than structural faults. They're horrible and sinister. We flew to Oz and back on Malaysia and liked the airline, good food too.
Last edited by: Armel Coussine on Sun 9 Mar 14 at 17:08
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...the Air France A340 lost off South America.
A330-200.
I like MH too. Nice crews, decent, modern hardware. And hot food, even on short flights. That prawn curry with egg and rice (and peanuts, and tiny dried fish) they offer for breakfast beats any dry croissant out of sight.
This will be a horrible week for the people who work there, as it is for those who knew people on the plane.
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Very sad for everyone involved.
I wonder if the previous wing damage contributed? If the repair failed and the wing stalled or slowed compared to the other then that May have contributed to the turn that was detected?
Total conjecture of course and one feels for the families that have lost loved ones.
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Wouldn't be the first time the crew have gone a bit 'funny' mid flight. Does seem an odd one.
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There was a recent hijack of a plane by the co-pilot who eventually sought asylum after locking himself in the cabin and landing the aircraft in a country he thought would prove hospitable.
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There was a recent hijack of a plane by the co-pilot who eventually sought asylum after locking himself in the cabin and landing the aircraft in a country he thought would prove hospitable.
An Ethiopian first officer who flew to Geneva. Equally bizarre in its way, since he could have flown his plane to Rome, as scheduled, walked out of the airport and caught a train to Switzerland, all quite legally and without arousing suspicion. Instead, he's likely to go to prison in Switzerland. I wonder whether 'failure to think it through' is grounds for refusal of a request for asylum.
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>> There was a recent hijack of a plane by the co-pilot who eventually sought asylum
>> after locking himself in the cabin and landing the aircraft in a country he thought
>> would prove hospitable.
>>
>> An Ethiopian first officer who flew to Geneva. Equally bizarre in its way, since he
>> could have flown his plane to Rome, as scheduled, walked out of the airport and
>> caught a train to Switzerland, all quite legally and without arousing suspicion. Instead, he's likely
>> to go to prison in Switzerland. I wonder whether 'failure to think it through' is
>> grounds for refusal of a request for asylum.
certainly makes you wonder about fitness for job as aircrew!
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>> certainly makes you wonder about fitness for job as aircrew!
Once again, not so sure. You can have a technical-sounding qualification or three and still be a dangerous fruitcake. Wasn't Osama bin Laden a psychologist? Perhaps it was another of those barmpots. Point is, you can have degrees in all sorts of psychology, variously coarse and doolally, without being anything but steadfastly mad and half-witted yourself.
I often say this here and elsewhere but I feel like a lone voice crying in the wilderness.
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>>
>> Once again, not so sure. You can have a technical-sounding qualification or three and still
>> be a dangerous fruitcake. Wasn't Osama bin Laden a psychologist? Perhaps it was another of
>> those barmpots. Point is, you can have degrees in all sorts of psychology, variously coarse
>> and doolally, without being anything but steadfastly mad and half-witted yourself.
>>
>> I often say this here and elsewhere but I feel like a lone voice crying
>> in the wilderness.
>>
You echo my own views, AC.
Intelligence and abilities can be highly compartmentalized, someone who is able or brilliant in one field can be unbelievably stupid in another.
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>> There was a recent hijack of a plane by the co-pilot who eventually sought asylum
>> after locking himself in the cabin and landing the aircraft in a country he thought
>> would prove hospitable.
>>
>> An Ethiopian first officer who flew to Geneva. Equally bizarre in its way, since he
>> could have flown his plane to Rome, as scheduled, walked out of the airport and
>> caught a train to Switzerland, all quite legally and without arousing suspicion. Instead, he's likely
>> to go to prison in Switzerland. I wonder whether 'failure to think it through' is
>> grounds for refusal of a request for asylum.
Depends on the sort of asylum he ends up in!
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>>
>> This gets curiouser and curiouser -
>>
>> www.telegraph.co.uk/news/worldnews/asia/malaysia/10690941/Missing-Malaysia-Airlines-plane-flew-hundreds-of-miles-off-course.html
>>
>> A highjack and deliberate crash or one of the crew gone a bit mad?
This is ultimate weirdness.
Plane shuts down its radio, turns off its transponders, and turns on a near 180 degree course?
And how good is Malaysian Military defences if they didn't scramble to a large unidentified radar contact inbound off the coast on a non civilian corridor?
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I wonder if they did, there will be things that aren't being released. Tensions are low but constant between countries in the region, I'd be surprised if they weren't put on alert, but perhaps not scrambled. I think they use Russkie stuff for Air defence.
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It only works if the staff are present and awake. Gets hot out there!
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When are they gonna tell us the troof: www.youtube.com/watch?v=129GD24bvj4
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Seriously, do aircraft like this use satnav, then they could automatically send location updates via radio and in the event of a catastrophe at least it could be located !
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>> Seriously, do aircraft like this use satnav,
GPS, yes
then they could automatically send location updates via
>> radio and in the event of a catastrophe at least it could be located !
And so it should have done. Except the transponders were turned off. That is the "WOW Mystery" part.
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They have a transponder, or several, on an up-to date craft, which send out data (position, altitude, i.d.) and can be tracked. If it is within ATC area. I believe it (they) can be switched off. List of disappearances here: en.wikipedia.org/wiki/List_of_aerial_disappearances One of which (1953) went into Lake Superior on UFO intercept. Apparently. Inserted as a red herring, to join the list of others proffered in the media:)
Last edited by: NIL on Wed 12 Mar 14 at 09:52
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avherald.com/h?list=&opt=0 A good summary of what is known (well it seems so to a layman!). Note incident on the 11/3 with a transponder, failed in flight.
Last edited by: NIL on Wed 12 Mar 14 at 10:18
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Help find MH370: tinyurl.com/po9msd3 (DM)
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Just saw an interesting piece on Sky news, apparently Boeing issued an "advisory" to all airlines to check the area where the gps and transponder pylon is mounted for corrosion. the theory put forward was that this pylon had come off causing loss of comms and depressureisaton and loss of consciosness of the crew.
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>> Just saw an interesting piece on Sky news, apparently Boeing issued an "advisory" to all
>> airlines to check the area where the gps and transponder pylon is mounted for corrosion.
>> the theory put forward was that this pylon had come off causing loss of comms
>> and depressureisaton and loss of consciosness of the crew.
Wow thats a 2+2=5 extrapolation.
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It's being given more credence on the pprune forum than the shaman the Malaysian government have allegedly consulted.
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A heist? A 777 has got to be worth £100m and it's easier than robbing a bank?
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>> A heist? A 777 has got to be worth £100m and it's easier than robbing
>> a bank?
>>
+ it comes with a few tons of gold in its hold if you pick the right one. :-)
Last edited by: Uncle Albert on Sun 16 Mar 14 at 17:32
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I just bet that the powers that be know where it is and what's going on.
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Ah the "powers that be". You mean the giant lizards who really control the planet? Yep they know all right.
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What phrase would you be better able to cope with?
Someone in charge at Malaysian Airlines, someone at Inmarsat, someone in charge of a radar site somewhere, someone in charge of a military installation?
I do not believe that the fate of that airplane is unknown, albeit not generally known.
The giant lizards do not have time to be involved in such a conspiracy, they're too busy writing your contributions.
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If these "poŵers that be" have all the answers why are they not telling the world. What supra-national power is organising this conspiracy? The answer is of course that no one knows where that aircraft is. It's odds on that it is at the bottom of the ocean somewhere with a good possibility it will never be found except by chance.
No international cover-up I'm afraid, just the usual bureaucratic cock-ups and incompetence.
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If the 'powers to be' have an idea of what has happened to the plane and where it is, do you think they would tell the new organisations who would therefore let those that have the plane know?
The plane may well now be at the bottom of an ocean or crashed onto land. But there seems to be evidence to say the plane turned west and then flew for a further 6.5 hours... Whether the plane landed somewhere is an unknown but some effort was taken to plan this it seems.
We can all speculate what happened. Maybe someone now has a 777 for future 9/11 style attack. Or a 9/11 style stack on the Petronas Towers was foiled last weekend and the plane carried on flying until out of fuel.... or.... well we can come up with all sorts of theories.
Last edited by: rtj70 on Sun 16 Mar 14 at 23:03
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>> we can come up with all sorts of theories.
Speak for yrself rtj. I haven't a clue and haven't any theories.
However the information given out so far leaves open the possibility that the aircraft may have landed somewhere more or less intact. That would be all right wouldn't it, not too many dead, survivors eating coconuts and reviewing their sinful former lives?
I'm just a Pollyanna. Can't help it.
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I can never stop myself personalizing these things. Whatever is the outcome, can you imagine the terror that 240 odd people have lived through? Whether or not it is over now.
As they say; there but for the grace of God.....
Awful.
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Whether the plane landed somewhere is an unknown but
>> some effort was taken to plan this it seems.
>>
>> We can all speculate what happened. Maybe someone now has a 777 for future 9/11
>> style attack.
The most unlikely, no - impossible scenario. For a number of reasons.
You don't just land a 777 on a hidden grass jungle strip. You can't keep 250 passengers quiet, specially as there is 250 mobile phones on board.
Its down, and its down in a state where the broken bits are not going to fly again. Where tho, thats the question. It will be found, (or its location will be known) I have no doubts, and it will be found soon-ish
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One example, amongst many possible, would be as R O'R said, why would you give away any advantage?
And why are you rattling on about conspiracy and supra-powers? And how are you so certain that your baseless assumptions are better or worse than anyone else's? And who said anything about a cover-up? I feel your need to appear casually, condescendingly and expertly superior in an anonymous internet forum is causing you to put words in my mouth.
I would assume that whatever level of information is available to us via the sensationalist media that the true breadth and quantity of information must be greater. Surely nobody tells everything? I wouldn't.
However, given your certainty of what is going on, I guess I'll just wait and see.
Unless, of course, you have some expertise, information or evidence that nobody else here or elsewhere is party to?
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I was just responding with sensationalist theories/idea to CGN. The plane probably crashed eventually but if it did, not anywhere near it's original flight plan.
And if it did turns out this plane was taken, I don't think there were any survivors amongst the passengers.... they are not part of any plan. But we know nothing really. I am sure killing all passengers whilst flying a hijacked plane is relatively easy.
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You state that you belief the "the powers that be" know what happened to the plane. The phrase "powers that be "implies"multiple organisations at high levels of authority know what is going on but are not telling.
That would have to involve a conspiracy and a cover-up would it not? Like you I have no idea what happened to the plane. Simply on the balance of probability it is now somewhere difficult to find. At the bottom of the ocean seems most likely.
Last edited by: CGNorwich on Mon 17 Mar 14 at 08:33
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For those who like theories that fit available "facts" - one here that someone has put a lot of work into.
The problem with the "not in the sea" theories is how the aircraft evaded detection. An explanation of how that might have happened is here.
Keith Ledgerwood blog goo.gl/RoYkj2
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>> I just bet that the powers that be know where it is and what's going
>> on.
>>
If the plane has been located intact and the passengers and crew are alive it would not be something they'd want known prior to a rescue attempt.
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The most sensible remark I've noticed in the media is: why would anyone go to the trouble of turning the communications off in a systematic manner and swooping down below the radar if all they were going to do was crash the aircraft?
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>>....and swooping down below the radar
>>
Another reason for "swooping down" is so you can breathe without an oxygen supply having depressurised the aircraft and killed all the passengers?
Last edited by: Uncle Albert on Mon 17 Mar 14 at 07:55
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Has anyone said its swooped down below the radar?
Certainly didn't "swoop down below the radar" when it (supposedly) flew back over Malaysia. And if you were going to fly over a country and hope not to be challenged you would keep the IFF transponder on, by turning it off you risk being intercepted by an airforce jet.
Last edited by: Zero on Mon 17 Mar 14 at 07:59
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Mad pilot? strong possibility, Hijacked? Strong Possibility, Hijack gone wrong? Strong possibility. Captured jet safely on the ground and hidden? No chance at all. The fact that someone somewhere in the powers that be knows where it is? Nah. What we have here is not deliberate deception or secrecy, but a genuine confused shambles.
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Heard a theory it dropped below usual cruising height so it didn't 'bump into' other aircraft around, but it wouldn't have affected fuel consumption too much.
The arc of it's possible course looks strange to me. I would've thought it would be a circle from it's last known position based on it's possible remaining fuel range. The published arc looks almost like it's based on whatever surveillance the US can see from Diego Garcia.
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>> The arc of it's possible course looks strange to me. I would've thought it would
>> be a circle from it's last known position based on it's possible remaining fuel range.
>>
The arc is from a satellite picking up signals
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Those arcs don't make sense to me.
As for dropping below the radar, it's my understanding that the aircraft did that after recrossing the Malay peninsula and reaching the Andaman Sea/Indian Ocean. If the aircraft lost compression, the passengers wouldn't all die instantly. Cruising altitude of 36,000 feet can be reduced to something much more breathable within a minute or so by descending quickly. Everest is 29,000 feet and people have climbed it without oxygen.
I would agree that if it has landed somewhere it probably won't have been a gentle landing. But crash landings don't always kill everyone on board.
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Landed somewhere?
I suspect every remote airfield capable of supporting a 777 has been visited by satellite by now.
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>> Those arcs don't make sense to me.
Derived from Satcom where it's possibly to measure the transit time for the signal from aircraft to satellite. As speed of radio waves are a known it's possible to approximate location and direction of travel. However, as only one satellite is involved there are two possible locations, being mirror images of each other. Second/third satellites would remove doubt as positions could be triangulated.
>> As for dropping below the radar, it's my understanding that the aircraft did that after
>> recrossing the Malay peninsula and reaching the Andaman Sea/Indian Ocean. If the aircraft lost compression,
>> the passengers wouldn't all die instantly. Cruising altitude of 36,000 feet can be reduced to
>> something much more breathable within a minute or so by descending quickly. Everest is 29,000
>> feet and people have climbed it without oxygen.
Man who did Everest w/o oxygen was an exceptional individual working to a routine allowing him to make most of available oxygen. Most people will suffer confusion or loss of conciousness at much lower levels. An airliner with a known decompression problem will descend to ten thousand feet or below ASAP.
Last edited by: Bromptonaut on Mon 17 Mar 14 at 12:11
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Here's a theory that makes a bit of sense (assuming his facts are true, of course, otherwise it's just pure fantasy):
keithledgerwood.tumblr.com/post/79838944823/did-malaysian-airlines-370-disappear-using-sia68
Quite possible that the passengers never knew anything. It was a night-time trip, and it would all have happened whilst it was dark/they were asleep. Unless somebody tells you something is up on an aeroplane, you are in a complete bubble.
If it has landed somewhere, then it's a long way from civilisation else somebody would have 'find my iPhone'd.
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>> Unless somebody tells you something is up on an aeroplane.....
Depends if there were any commuters / regulars on the flight.
At one point I was commuting between my house in San Fran and my apartment in Sao Paulo, Brazil via DFW - a long night flight. I ended up being very aware of what was going on, and if anything was different.
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I would think that rule one for the crew is if at all possible don't frighten or upset the passengers.
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Manatee posted the same link a little earlier than you. And interesting article. It seems there was likely to be another 777 heading north (and onwards to Barcelona) when the Malaysian 777 was in the area having crossed back over the land.... so how plausible for it to fly behind it for a distance?
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The theory that it might have followed the SIA flight, or another large airliner, has been posited several times on PPRUNE. In the absence of any clues I'd regard it as more plausible than some of the theories doing the rounds.
As to following for distance I'd have thought not to problematic, certainly if it could be kept in sight. Need to keep out of lead aircraft's wake turbulence but in known wind etc conditions the wake will be predictable.
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I was thinking more along the lines wouldn't other radar systems detect two planes in close proximity but only one broadcasting it's details via a transponder?
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>> I was thinking more along the lines wouldn't other radar systems detect two planes in
>> close proximity but only one broadcasting it's details via a transponder?
All any radar would see of the aircraft with its transponder off would be a primary return - the 'echo' of the outgoing pulse.
No expertise in this beyond years of 'earwigging' ATC but I suspect unprocessed primary returns are subject to interference, ground returns, weather etc. A second, similar sized return apparently 'shadowing' an identified airliner and showing similar speed/direction might just be assumed to be an 'oddity'. Targets behaving like an airliner on a known route might not be a priority for defence systems looking for smugglers or incursions by military aircraft of nearby hostile states.
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So a blip flying out there might just be ignored - I hope such a blip isn't ignored say coming into London Heathrow!
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>>Quite possible that the passengers never knew anything.
>>
>> It was a night-time trip, and it would all have happened whilst it was dark/they were asleep.
>>
Normally refreshments and a meal before lights out and they were not far into their trip
.
I have only ever been on one flight where the CC said" We are sure you want to sleep so we are dimming the lights and if anyone does still want drinks of food just let us know. AI full English will be served closer to home."
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Yes, but they were flying over land at that point, so doubtless within mobile phone/data signal at some point. If somebody had been aware of funny business, somebody would have sent the message out.
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News media are placing some significance on the fact that the final radio transmission was made by the co-pilot. Normal operating procedures mean that there are a Captain and a First Officer on any flight, but, it is perfectly normal for a First Officer to be designated fly a sector and thus handle the comms. So long as someone spoke the matter of who did doesn't affect anything.
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>> Yes, but they were flying over land at that point, so doubtless within mobile phone/data
>> signal at some point. If somebody had been aware of funny business, somebody would have
>> sent the message out.
I understand you need to be within 2-3 miles of a mast, if so anything over 15000 feet would probably put you out of range.
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Given that with my Nokia 5210 in dover I could connect to France telecom - its more about line of sight.
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Yup, line of sight. Bit of height and range is many times better.
I have an amateur radio licence and from almost the top of Helvelyn, I contacted someone in South Wales using a VHF transceiver that would be doing well to go 20 miles normally.
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>I understand you need to be within 2-3 miles of a mast,
I forgot to switch off RF on my phone before we got on the plane going on holiday. It was in my carry-on in the overhead.
When we got to our destination I had at least half a dozen "Welcome to XYZ Telecom" messages from countries we had overflown at 36 to 40,000ft including one from an Iranian network.
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Another urban myth then, like the one about covering your body in gold paint?
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The maximum theoretical distance a GSM phone can be from a mast is 35km:
en.wikipedia.org/wiki/Timing_advance
and 40,000ft (~7.5m) is well within that. I would have thought that the speed of the plane would be more of a problem - can't remember what the max supported GSM handset speed is, but I didn't think it was much over 100mph?
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If the minimum range from the mast is ~7.5m the frequency shift will dramatically reduced.
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>> I would have thought that the speed of
>> the plane would be more of a problem
Perhaps it's the speed directly towards or away from the mast that counts, which isn't that high as long as the pilot doesn't dive-bomb the mast.
EDIT: which I think is what UA said
Last edited by: Focusless on Tue 18 Mar 14 at 11:18
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>> EDIT: which I think is what UA said
>>
More or less. Doppler (frequency) shift is one of the techniques that submarines use to establish the range of vessels that they are listening to.
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>> >> EDIT: which I think is what UA said
>> >>
>>
>> More or less. Doppler (frequency) shift is one of the techniques that submarines use to
>> establish the range of vessels that they are listening to.
Doppler shift is used to measure the speed of the target
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.
Last edited by: Focusless on Tue 18 Mar 14 at 12:28
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>> Doppler shift is used to measure the speed of the target
>>
It must be if you say so. I forgot that you are a target motion analysis expert.
Last edited by: Uncle Albert on Tue 18 Mar 14 at 14:49
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well clearly you weren't.
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>> well clearly you weren't.
>>
Why would you need frequency shift to determine a contacts speed? That is almost instantly established on initial contact and continuously monitored.
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If something is coming towards you, then the waves it is reflecting at you become closer and closer together. (since for each wave it is reflected slightly sooner/closer than the previous one).
If something is moving away from you then correspondingly the waves reflected at you become further and further apart.
The speed of those waves is essentially the frequency, and the change in the frequency is called "The Doppler Effect".
The fact that there is a change determines that there is movement. The speed of that change allows calculation of the speed of that movement.
The other effect used by Radar is "The Echo Effect". This tells you the direction of a given contact.
Whilst the same transmission can be used for both determining both direction and speed, it is the actual effect utilised which is different.
Last edited by: No FM2R on Tue 18 Mar 14 at 15:49
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Radar does not work very well under water. :-)
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oops, Sonar. The effects used are the same.
Would have been simpler if they just made Radar waterproof.
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>> Radar does not work very well under water. :-)
But sonar works exactly the same way as radar.
Last edited by: Zero on Tue 18 Mar 14 at 16:03
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>> But sonar works exactly the same way as radar.
>>
Rubbish.
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Well, it pretty much does. One utilises electro magnetic waves passing through air, the other uses sound waves passing through water. But other than that.....
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Good Lord, what did you do on HM submarines, clean out the heads?
Radar send out a radio pulse and records the return.
Sonar send out a sound pulse and records the return,
Last edited by: Zero on Tue 18 Mar 14 at 16:16
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>> Sonar send out a sound pulse and records the return,
>>
Do you get your knowledge from WW2 ping ping movies?
If you ping these days you give away the fact that you are around, your position and identity, and you could get shot at.
Things have moved on.
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I sense I'm getting involved in something I should leave you two to...
However, Active Sonar and Radar use the same principles.
Passive Sonar simply means solely listening rather than generating your own signal and listening. Passive Sonar is thus dependent on third party noise and cannot determine range since it has no possible comparison against a known signal.
It can, under certain circumstances, determine movement towards or away from itself by measuring changes in a constant signal - if it can determine that the signal is constant.
Now, what is it exactly that you two wish to argue about?
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They use passive sonar, but there is still a sound source.
AND EVERY submarine STILL has active sonar. Go back to cleaning the heads, leave the technical stuff to those who were bright enough to be trained.
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Zero, you know that I am constrained as this is a public venue, suffice to say that I ran the sonar department of a nuclear submarine for several years. I now bow to you greater knowledge.
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It had crossed my mind you guys were trying to trick Uncle Albert into revealing stuff he should take to his death bed. Daft to challenge him and you (Zero/NoFM) are incorrect in your assumptions about limitations of passive sonar... developments in the 70s exceeded the performance you assume... goodness knows how effective it is these days.. The is more in the public domain if you intensively Google the topic.
Going back to a comment NoFM made well upthread about "the powers" knowing loads more re the aircraft... of course they will but the agencies involved will not be telling us or the Daily Mail.
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>> It had crossed my mind you guys were trying to trick Uncle Albert into revealing
>> stuff he should take to his death bed. Daft to challenge him and you (Zero/NoFM)
>> are incorrect in your assumptions about limitations of passive sonar... developments in the 70s exceeded
>> the performance you assume...
I assume you are talking about the BQQ5. It could do a lot. It could not, however, rewrite physics.
It cant provide "range on initial contact" passively for instance. Especially if that sound source is between thermal layers.
Last edited by: Zero on Tue 18 Mar 14 at 17:02
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Fenlander?
>>It had crossed my mind you guys were trying to trick Uncle Albert into revealing stuff he should take to his death bed.
1) Why on earth would I waste my time thus?
2) Have you ever known me to be underhand? A git at times, perhaps. but underhand?
3) Why would you think that Zero and I collude on anything, never mind something as trivial as this?
For once I think I am actually offended rather than pretending so.
>> incorrect in your assumptions about limitations of passive sonar... developments in the 70s exceeded the performance you assume
Goodness knows what they've done in the last 10 years or so, but I assure that you that I'm a lot more uptodate than the 70s.
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>>>For once I think I am actually offended rather than pretending so.
Nope... still pretending... it would take far more than an inoffensive forum post.
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>> it would take far more than an inoffensive forum post.
Yes, it would; for example that someone genuinely believes me to be underhand.
But offended isn't quite the word. But then neither is "hurt" or "insulted".
Perhaps "bothered" is the word.
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>> Perhaps "bothered" is the word.
>>
Don't fall for Zeros wind up.
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you really are a stupid old sod.
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>> Zero, you know that I am constrained as this is a public venue, suffice to
>> say that I ran the sonar department of a nuclear submarine for several years. I
>> now bow to you greater knowledge.
Given the knowledge you have displayed here. I don't think so.
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>> Given the knowledge you have displayed here. I don't think so.
>>
It is a job that is head hunted by submarine captains, (no fools).
You would not last a week if you were not up to it.
Stop digging Z the hole is too deep for you already. :-)
Last edited by: Uncle Albert on Tue 18 Mar 14 at 17:08
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>>you give away the fact that you are around, your position and identity
Your presence: Agreed.
Your position: No, simply your bearing.
Your identity: Perhaps.
If you and another submarine some distance away both utilise passive sonar, you should be able to triangulate. Assuming you can communicate discretely.
Last edited by: No FM2R on Tue 18 Mar 14 at 16:32
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Reading abut Doppler shift got me recalling dim memories of the Trident's Doppler navigation system. I then found a thread on PPRUNE about the Trident and lost an hour of my life:
www.pprune.org/archive/index.php/t-434496.html
The posts describing Doppler start at 18:33 on 02/12/2010.
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>> >> well clearly you weren't.
>> >>
>>
>> Why would you need frequency shift to determine a contacts speed? That is almost instantly
>> established on initial contact and continuously monitored.
Well Doppler shift can't measure range.
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>> Well Doppler shift can't measure range.
>>
Wrong again Zero, You should stick to things you actually know a little about, at least your ignorance of this subject is entertaining.
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Wow, just woken out of your coma? Still those cogs turn pretty slowly don't they
And not wrong. Doppler shift does not measure range
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>> Wow, just woken out of your coma? Still those cogs turn pretty slowly don't they
>>
>>
>> And not wrong. Doppler shift does not measure range
>>
Don't kid yourself, you are not even on my list of priorities.
There are those who know and those who like to think they know. Why did you mention BQQ5? That is ancient kit, dated in my day, why not name some of the newer UK sonars, even 20 year old ones will do. They are way in advance of anything, or any techniques you have mentioned, and have no doubt advanced considerably since I retired.
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>> >> Wow, just woken out of your coma? Still those cogs turn pretty slowly don't
>> they
>> >>
>> >>
>> >> And not wrong. Doppler shift does not measure range
>> >>
>>
>> Don't kid yourself, you are not even on my list of priorities.
>>
>> There are those who know and those who like to think they know. Why did
>> you mention BQQ5? That is ancient kit, dated in my day, why not name some
>> of the newer UK sonars, even 20 year old ones will do.
Because it was an answer to a statement about a a US breakthrough in the 70s. And the BQQ5 was that breakthrough. Do learn to follow a discussion thread.
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>> Because it was an answer to a statement about a a US breakthrough in the
>> 70s. And the BQQ5 was that breakthrough. Do learn to follow a discussion thread.
>>
I will take that as "I don't know".
The BQQ5 was based on UK kit, and was only one of several breakthroughs, and not the main or most significant one.
Last edited by: Uncle Albert on Thu 20 Mar 14 at 18:44
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>> >> Because it was an answer to a statement about a a US breakthrough in
>> the
>> >> 70s. And the BQQ5 was that breakthrough. Do learn to follow a discussion thread.
>>
>> >>
>>
>>
>> I will take that as "I don't know".
What part of that did you not understand then? Do I really have to go back through this thread and stitch the bits together for you?
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>> What part of that did you not understand then? Do I really have to go
>> back through this thread and stitch the bits together for you?
>>
You are really struggling, just keep digging, the whole forum is having a good laugh at your expense. :-)
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If it helps to clarify....
I wasn't referring to a US development in passive sonar... or the BQQ5 system. Just the general advances in passive sonar from the 70s onwards.
Last edited by: Fenlander on Thu 20 Mar 14 at 18:59
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No problem Fen, there are very few people who know the whole story of the development of sonar systems and their associated sensors. And they don't tell, that's why Zero is on a loser.
Last edited by: Uncle Albert on Thu 20 Mar 14 at 19:05
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Ok UA, tell us, technically, how Doppler Shift is employed on first contact, to obtain the range of a target using passive sonar
Oh and "I can't tell you because its a secret" means - I got it wrong.
Over to you
Last edited by: Zero on Thu 20 Mar 14 at 19:37
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>> Over to you
>>
You will find words to the effect of "Frequency shift varies with range from the GSM mast" in this thread. That is the only hint you are going to get.
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You even got that wrong you berk.
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Oh forget it, you have lost all sense. It ends here.
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A smiley face because you think you scored a point?
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>> A smiley face because you think you scored a point?
>>
No not at all, Zero was trying his usual wind up tactics, unfortunately he chose the wrong subject. Just letting him know there are no hard feelings, he could lose me in seconds on computer geek stuff.
If anyone is interested Google "Narrowband sonar TMA".
Last edited by: Uncle Albert on Thu 20 Mar 14 at 21:55
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And you know what? It does not use doppler shift to detect range.
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Well I am not using any wind-up tactics nor conniving to get you to reveal something you should take to your grave, whatever Fenlander believes. It is an interesting subject though.
Its worth mentioning that I don't really see it is a point scoring exercise; its either teaching or learning, and I enjoy both. And anyway I'm bored.
One can extrapolate nothing from a single measurement other than presence, unless one *knows* the characteristics of the origin, which would, in itself, be a second measurement.
With active sonar one knows the qualities of the transmission and can make limited assumptions with a single transmission although multiple transmissions tell more. But what one is measuring is measurable differences between the origin and the return. one is able to arrive at conclusions because both origin and return are known and thus change is also measurable.
With passive sonar one cannot know that one knows the characteristics of the originating signal. Consequently multiple measurements must be taken involving a known change or difference (could be changing course, angle or speed and measuring again, a second measurement from another vehicle or buoy, or a second measurement of another source for comparison etc. etc.), and that difference can be time or distance or indeed origin. That happens fantastically quickly, nonetheless it is, and must be, multiple measurements.
In both cases, active and passive it is the change or difference in measurements which is most informative. One can *only* measure change, difference or indeed similarity with multiple measurements - where "multiple" includes cases of more than one listener, or comparison to known or historical data.
As in this discussion where the term "Doppler Shift" involves measurable change (the clue is the word "shift").
Now using a Monte Carlos analysis would require a huge amount of measurements and thus only realistically possible if automated. As an aside I intensely dislike the MC approach, especially when people try to apply it within a business environment.
Of course there is always the increasingly important but difficult to determine difference between "knowing" and "extrapolating" reliably/accurately"
And a Monte Carlos analysis, or any other use of multiple measurements to form a determination is absolutely NOT knowing, it is only statistically accurate and informed guessing.
So Zero is correct in that a single measurement is insufficient (unless the origin characteristics are known).
Your point seems to be correct in that over a period of time or range of measurements one can extrapolate range and speed/direction of travel.
However one does it though, one needs to make use known doppler and echo performance.
Yours seems to be that you can detect all using only passive sonar. Which is reasonably true, but only by causing or measuring known change. Active sonar is much better for this, but obviously gives away information as well as determining it.
So as far as I can see, you two are not even arguing the same points.
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If you have a stationary target emitting plant noises, and you are in a stationary listening platform, you can not detect range using doppler shift because there is no shift.
Doppler detects speed and speed is one of the parameters used in TMA from which you can determine range comparing your speed, the target speed and bearing. You can even throw in natural fixed and plotted sound sources like magma displacement, eddies, and flow noises, comparing rate of change between target and those known sources.
Doppler shift measures speed (or rate of change) and throws that into the mix. On its own it does not detect range.
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I know all we need to know from the Hunt for Red October. Including the fact Russian submarine commanders have Scottish accents.
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>> So as far as I can see, you two are not even arguing the same
>> points.
>>
Correct, I realised that long ago. :-)
Last edited by: Uncle Albert on Thu 20 Mar 14 at 22:44
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>> >> So as far as I can see, you two are not even arguing the
>> same
>> >> points.
>> >>
>>
>> Correct, I realised that long ago. :-)
You are telling porkies pies my old son. You are grabbing that as a lifebelt.
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With a towed array I would imagine that it is quite possible to accurately determine the range and speed of a sound source passively (up to a certain range).
By comparing the time difference between identical portions of the signal received by multiple sensors along the hull and towed array you can triangulate the position of the sound source. By measuring the rate of change of those signals and your own (known) speed you can calculate relative velocities and therefore the source's speed and direction.
If you know that different sound signatures (high/low frequency mixes) are emmitted by different portions of the source's hull (eg. nose, tail or tower) then you could probably also calculate if it was on a steady heading, turning or even changing depth.
I am far from being an expert but I've worked on active sonar measurement equipment, and with today's signal processors I guess results would be almost instantaneous.
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>> With a towed array I would imagine that it is quite possible to accurately determine
>> the range and speed of a sound source passively (up to a certain range).
You need to be moving to tow the array, and you need to let it straighten after a turn.
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>You need to be moving to tow the array, and you need to let it straighten after a turn.
I have no idea how they actually get around location problems, but it is perfectly feasible to construct a neutrally buoyant array with a reverse mechanism to keep the line extended. It is also perfectly feasible to include sensors and software to compensate for sensor movement.
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Zero is right, a towed array has to be straight, and it is neutrally buoyant. It can be used in the turn by an experienced operator to maintain a mental picture of the situation and to predict where to look for contacts when it straightens after a turn. As its primary use is long range detection bearing movement of contacts is not generally a problem. It can be used for triangulation ranging amongst other things. Probably more things since I retired and computing power has improved.
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>> >You need to be moving to tow the array, and you need to let it
>> straighten after a turn.
>>
>> I have no idea how they actually get around location problems, but it is perfectly
>> feasible to construct a neutrally buoyant array with a reverse mechanism to keep the line
>> extended. It is also perfectly feasible to include sensors and software to compensate for sensor
>> movement.
Problem is your tail is bent, and if your tail is bent a proportion of your hydrophones (which they try and make pretty directional) are not in line with your target so are not picking up any target sound. No amount of signal processing or computing can make up for loss of sound. Also another proportion of the hydrophones are bent into your wake degrading their performance, despite the fact the tail is very long to get it as far away from your own wake and noise as possible.
Last edited by: Zero on Fri 21 Mar 14 at 08:14
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Careful Z, you are getting into an area you do not fully understand and you are liable to mislead people.
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>>Talk to the Hand.>>
Really? there are four errors in your 08:13 post.
You need to check your hydrophone theory, towed array dynamics, beam forming, and most surprisingly for a computer geek, signal processing.
It is obviously a pointless discussion with someone who does not have adequate knowledge of towed arrays and their use, and as you know I am limited in what I can disclose.
Last edited by: Uncle Albert on Fri 21 Mar 14 at 09:04
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Ah the Old "i can't disclose" meaning "I don't know" excuse again
Talk to the hand.
Last edited by: Zero on Fri 21 Mar 14 at 09:12
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>> Ah the Old "i can't disclose" meaning "I don't know" excuse again
>>
>> Talk to the hand.
>>
At least I have used the kit, taught its use, trained its operators, assessed its performance, and accepted the equipment into service. What is your background in this field?
Last edited by: Uncle Albert on Fri 21 Mar 14 at 10:36
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>> >> Ah the Old "i can't disclose" meaning "I don't know" excuse again
>> >>
>> >> Talk to the hand.
>> >>
>>
>> At least I have used the kit, taught its use, trained its operators, assessed its
>> performance, and accepted the equipment into service. What is your background in this field?
Ah! All is explained, that's why sub skippers keep hitting things, using Doppler shift for range
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Have you come off your anti arrogance medication?
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>Problem is your tail is bent,..No amount of signal processing or computing can make up for loss of sound.
I don't think that you would need all of the sensors to be receiving a signal once you have determined the direction, range and relative velocity of a target. If you begin a turn, it should be quite simple to use gyro information to predict the target's present position. If you apply a "confidence" algorithm to the remaining sensor signals you can refine that prediction even further.
*/ Devils Advocate
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>> I have no idea how they actually get around location problems, but it is perfectly
>> feasible to construct a neutrally buoyant array with a reverse mechanism to keep the line
>> extended.
A towed array is an inert device. Its object is to provide a totally silent listening platform.
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>A towed array is an inert device. Its object is to provide a totally silent listening platform.
Maybe I wasn't clear enough in my term "reverse mechanism".
Perhaps I should have said "designed by experts in fluid dynamics to provide sufficient drag and stability to maintain optimum sensor alignment".
Jeez,
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My profuse apologies, please carry on with your mechanical array.
There is a mechanism on the other end, it is called a winch. :-)
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>My profuse apologies, please carry on with your mechanical array.
>There is a mechanism on the other end, it is called a winch. :-)
If you are trying to tell me that a towed array is just a bunch of sensors on a wire using a winch to maintain stability I'm beginning to think Zero is right. Glub forbid.
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If you know how an array is constructed (and you obviously don't) I will leave you to it.
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>> If you are trying to tell me that a towed array is just a bunch
>> of sensors on a wire using a winch to maintain stability>>
As you seem to have misunderstood the "winch" bit, a towed array has to be retractable to allow the vessel it is fitted on to transit shallow water, enter and leave harbour etc.
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To me as a lay person in these matters, the concept of a towed array to me is:
- Some sensors towed behind the submarine
- A connection from the sensors and the submarine systems
- A mechanism to deploy/retrieve the array (a winch for want of a better word).
The towed part is behind the submarine so it can listen etc. a distance behind.... All sounds simple apart from the technology. The design even an obvious one. What is this lat person missing Zero/Kevin?
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>> To me as a lay person in these matters, the concept of a towed array
>> to me is:
>>
>> - Some sensors towed behind the submarine
>>
Or any vessel, a submarine has the advantage of being covert. You are right, the technology behind the sensor is the clever bit.
Kevin sounds like Zero coming back in disguise. :-)
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>The design even an obvious one. What is this lat person missing Zero/Kevin?
You're not missing anything rtj.
Uncle Albert is trying to convince us that he is savvy in some super-dooper secret sonar technology. He could tell us what it is but he won't because if he did he'd have to kill us.
It ain't working.
Personally, I'd like to spend an hour or two with a designer of the signal processing systems. That would be interesting.
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>> Personally, I'd like to spend an hour or two with a designer of the signal
>> processing systems. That would be interesting.
>>
Some of the technology involved is in the public domain if you know what to look for. It is its application, capabilities, and use that you will not find.
I don't give a stuff what you think of me, there are folk on this forum who know my background.
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>Some of the technology involved is in the public domain if you know what to look for..
Pretty much all signal processing technology is public domain and off-the-shelf. I can buy it out of the Farnell catalogue. Probably at one tenth of what the MOD end up paying for it.
>It is its application, capabilities, and use that you will not find.
I know it's application, I know it's capabilities. I can read a spec-sheet. I could build a simple signal processing system in my spare room over a weekend. How it is used specifically in sonar systems is something only the system designer could explain.
>I don't give a stuff what you think of me, there are folk on this forum who know my background.
I have no fixed opinion of you Uncle Albert, in fact I find most of your posts entertaining. But your misreading and snide replies to some of the posts in this thread are rather unusual.
Maybe it's a communication problem?
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>> Probably at one tenth of what the MOD end up
>> paying for it.
At least you got that right.
I don't think you have the remotest idea of a nuclear submarines sonar capabilities.
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>I don't think you have the remotest idea of a nuclear submarines sonar capabilities.
Uncle Albert,
am I not explaining myself clearly enough or do you have reading comprehension difficulties?
I was not referring to submarine sonar capabilities. I was referring to signal processing.
If you read further up this thread you will see that I've already stated that I'm no expert in submarine sonar. I do however have experience of industrial sonar equipment and signal processing so I'm not a complete neophyte.
All we've seen from you so far are unsubstantiated claims of 'You lot know jack all. I'm the expert' and snide comments like the ones above and below.
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>> You lot know jack all. >>
Correct.
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What a thoughtful, considered and erudite reply.
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>As you seem to have misunderstood the "winch" bit, a towed array has to be retractable ..
Duh! Although I can see why that might need to be explained to Naval personnel.
>Kevin sounds like Zero coming back in disguise. :-)
And you are beginning to sound like a broken record. A 78 in the world of MP3s.
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>> The maximum theoretical distance a GSM phone can be from a mast is 35km:
>> en.wikipedia.org/wiki/Timing_advance
>>
>> and 40,000ft (~7.5m) is well within that. I would have thought that the speed of
>> the plane would be more of a problem - can't remember what the max supported
>> GSM handset speed is, but I didn't think it was much over 100mph?
>>
Going back 15 years my employers were implementing extended cell for GSM which doubled that to 70Km at the cost of half the capacity per RF carrier, not sure if that's still used but agreed timing isn't going to be an issue.
Doppler's already been discussed, from memory of tests I did 15+ years ago pretty standard GSM codecs could give a usable call quality at 330Km/h ( German ICE trains being the use case). Maximum specified GSM speed is still only around 150 Km/h though, from memory.
In general antennas are chosen with minimum gain above the base station site as that's wasted power, better to squirt the RF horizontally where it will provide usable coverage: but inevitably there will be some power radiated upwards. In addition there are plenty of base station sites on mountains* where aircraft are probably not far above the intended coverage area.
* The last equipment I worked on was required to be transportable to installation site by mule/donkey!
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>> In general antennas are chosen with minimum gain above the base station site as that's
>> wasted power
Ah yes, good point.
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www.bbc.com/news/magazine-26609687
Quite interesting to read, but essentially can be summed up as "we have no idea what happened".
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Well at least one good thing has come out of this whole Affair.
mark has found something about the BBC he likes.
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Funnily enough that thought occurred to me; so rare to read a BBC article without some kind of sensationalism or ulterior agenda.
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Chinese people awaiting news of the Malaysian Airlines flight are going on hunger strike in protest at the lack of information. I wonder how they think this will progress the search and investigation?
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And it would be somewhat ironic if a relative starved themselves to death in protest and the plane is found and passengers are alive. Although I think the passengers will all have died - even if the plane is intact somewhere.
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Those "powers that be" are keeping remarkably quiet.
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.
Last edited by: No FM2R on Tue 18 Mar 14 at 14:49
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The Media and the relatives are unable to accept that there is "No News"
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Threats of a hunger strike are entirely unreasonable and pointless of course, but one can imagine that such feelings of helplessness might drive quite ridiculous statements.
We may well find out that the plane was destroyed by one means or another.
We may well find out that the plane was intentionally and successfully taken.
It is hard to see how either of those possibilities result in the 250 passengers remaining alive by this point.
Last edited by: No FM2R on Tue 18 Mar 14 at 14:53
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How long before the first film?
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who will play the part of the pilots?
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Don't know, but they should send for Bruce Willis to find the plane.
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>> How long before the first film?
>>
Well the TV series has already been made - Lost.
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International Rescue would have found it - but there would have been strings.
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This one sounds more convincing.
indiatoday.intoday.in/story/missing-malaysian-jet-mh370-google-plus-langkawi-chris-goodfellow/1/350052.html
But what I don't get is why, if the pilot headed west towards Langkawi, George then took the plane off on the route with the known red lines.
Also, with complete electrical failure it seems odd that the engines were still pinging.
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Anyone actually established what the cargo was? Rumours of gold, but I don't think anything was confirmed by Malysian?
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3 tonnes of mangosteens are all they are owning up to.
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Whats the current price on mangosteens?
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Interesting view but it doesn't tie in with the pings (perhaps they were from another plane?).
plus.google.com/app/basic/stream/z13cv1gohsmbv5jmy221vrfyiz3vdhbop04
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How do passenger's phones behave in flight. I was in a garden centre last Friday and I had no signal at all. I put it down to the metal construction of the place. It was ok in the car park.
We were hardly in a remote area with no coverage.
HO
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The nearer to uninterrupted line of sight and the least interference from other radio sources one has, the greater range the telephone connectivity has. Warehouses, and that's pretty much what your average garden centre is, frequently have bad signal.
In my experience the plane has to be a lot closer to the ground than a cruising height of 35k ft for the phone to acquire a signal.
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I have managed to get mobile signal at 35k, and GPS signal as well.
TomTom speed cameras are really not very happy at all at 540 mph.
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I've not tried to get a phone signal but have used GPS on a flight. Takes time to get a fix on a plane but that's probably because line of site to enough GPS/GLONASS satellites is an issue at 35000+ feet. And the aircraft construction is a factor too. Or do others get quick GPS fix on planes?
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I've never purposely tried, and so my phone / blackberry / whatever is normally in my bag and either switched off or in "airplane mode". I'm far too busy drinking trying to forget how much I hate travelling to try working.
However, on the occasions I have forgotten to disable my device, I have never arrived to find it having been welcomed by a multiplicity of countries as it flew over them. And I have ever bit of potential connectivity turned on all the time, roaming and home.
Not doubting you at all, but I'd guess it is the exception rather than the rule.
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p.s. never even tried GPS. Although I do rather enjoy the imagined look of panic on the sat nav's face when I turn it on in a different country/continent to where I turned it off.
Last edited by: No FM2R on Tue 18 Mar 14 at 23:49
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I have a simple phone. I don't remember ever being welcomed by countries being overflown, but anywhere the plane landed would say hello and goodbye, indicating courteously that you were connected and could use the thing. .
A rare example of modern crap working to the ccitizen's advantage I tend to think.
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If any of you have nothing to do, the discussion on Pprune is approaching 10,000 posts! There was discussion yesterday, of the possibility of a fire in the hold. Why that would make the crew disable the transponders I have no idea.
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If it is on the ground almost anywhere, surely US spy satellites would spot it?
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>> If it is on the ground almost anywhere, surely US spy satellites would spot it?
I would have thought they (or at least someone) would have pictures of it in the air, enough to see where it had gone? Which leads to one of the 'they know but are keeping quiet' theories.
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>> I would have thought they (or at least someone) would have pictures of it in
>> the air
www.dailymail.co.uk/news/article-2583807/Did-Malaysian-tuna-fisherman-missing-flight-MH370-flying-low-Gulf-Thailand-tried-stay-radar.html
(DM has been reporting about 5 new theories every day)
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>> A rare example of modern crap working to the citizen's advantage I tend to think.
Might have something to do with the fact that the phone companies make a fortune from roaming charges though (or used to, perhaps not so much now?).
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>>
>> Not doubting you at all, but I'd guess it is the exception rather than the
>> rule.
>>
Indeed, the expensive to generate RF power is much more profitably employed being squirted over terra firma where there are far more potential punters.
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How's that another theory? There are links to this Keith Ledgerwood article from a few days ago in this thread. Keep up.
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From the purely aviation side, there appears to be no real indication of a mechanical failure so no investment by Boeing to find the black boxes, unlike Airbus with the Air France event.
777s are not going to fall out of the sky.
From the humanitarian side I wonder how much more effort will be spent searching?
If they find where it is in the ocean they are unlikely to recover it.
If they recover the black boxes, IIRC the voice recorder overwrites every two hours so that will be of limited use.
A comment from Pprune.
"Time to let it go, this aircraft will not be found ever! "
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>> 777s are not going to fall out of the sky.
Er, one just did.
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In aviation industry, every loss must be investigated to ensure similar incident does not happen again in future.
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>> In aviation industry, every loss must be investigated to ensure similar incident does not happen again in future.
>>
Of course I agree with that theory.
9/11??? Four aircraft
They did not know immediately the aircraft locations were because the transponders were switched off.
Air France 447 - where did it go to
MH370 - where is it?
When the question was asked on Pprune about transponders being locked the lame response was that they are known to go wrong.
Spend a few more $$$ to sort things? Nah the bean counters are king.
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>> >> 777s are not going to fall out of the sky.
>>
>> Er, one just did.
>>
Or maybe flown into the sea?
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>> >> >> 777s are not going to fall out of the sky.
>> >>
>> >> Er, one just did.
>> >>
>> Or maybe flown into the sea?
>>
Deliberately? Why? Why is no-one claiming responsibility if so. Hijackers, terrorists - they all want you to know about them, otherwise, well, where's the fear?
No, I'm sorry, but Mr O Razor says: "There was a malfunction of some kind and it fell out of the sky". Gravity's a beeatch.
Last edited by: Alanović on Wed 19 Mar 14 at 11:06
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No - it may have landed somewhere although I agree it is unlikely.
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>>A comment from Pprune.
>>"Time to let it go, this aircraft will not be found ever! "
A prune indeed.
Was not something similar once said about a plane in the Andes?
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"Was not something similar once said about a plane in the Andes?"
They said something similar about Amelia Earhart and her plane too but there again they never found either. Yes I know a 777 is a lot bigger and search resources are a lot more sophisticated now but the world is still a very large place, most of it ocean and a lot of the search area consists of some of the deepest oceans in the world. Without some idea of where that aircraft hit the sea the chanced of finding it are remote, and its pretty clear that nobody has any idea where to look.
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Debris seen off the coast of Australia.
www.bbc.co.uk/news/world-asia-26659951
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Debris seen off the coast of Australia.
www.dropbox.com/sh/yhsswgva7dso90m/c3RchRtULZ#lh:null-DIGO_00718_02_14.jpg
- good that we have professionals doing the interpretation. Otherwise might as well be tea leaves :)
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"Nothing Here
The file you're looking for has been deleted or moved."
It was there when I posted, ( as I checked that link was working ok after posting :), but seems to have gone now. Sorry.
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>> >> Try www.pprune.org/rumours-news/535538-malaysian-airlines-mh370-contact-lost-328.html#post8389571
>>
>> "It could be" the tail of the plane.
Another later post - "Whatever that object is, it can't be the tail" ...
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How big is a shipping container.................
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From PPrune postings .
There are the normal ( larger) shipping containers we see on trucks and now some even larger ones are being made.
Neither match the size of the items in the sea.
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The Norwegian car carrier Hoegh St. Petersburg has reached the area in the southern Indian Ocean off Australia where two floating objects, suspected to be debris from the missing Malaysian jetliner, were spotted, the ship owner’s said on Thursday. The cargo ship is currently 30 NM from the location of the objects.
The car carrier was on its way from Madagascar to Melbourne
A Motoring link :-)
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Doinggggg........
...tit!
(repeat as necessary)
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>> Debris seen off the coast of Australia.
End of 2nd day searching but nothing found yet:
www.bbc.co.uk/news/world-asia-26677056
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We're those sat images of floating debris? How long do 24 metre bits of airframe float?
I would guess they are searching for the black box transponders.
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Apparently the currents are quite strong in that area, so I believe that anything spotted on the satellite pictures could have shifted considerably by now.
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I just wonder if it is not time to accept that the plane and its human crew are gone and the cause may never be known.
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>> I just wonder if it is not time to accept that the plane and its
>> human crew are gone and the cause may never be known.
At some point that may be inevitable but the aviation industry will be very chary of 'cause not known' loses of lives and hull. It was only after the second unexplained loss of a Comet, G -ALYY after G- ALYP, that the cause of accidents was fully investigated and found.
Malaysian is a reputable operator flying to standards of EU/US and we can no longer write off accidents where only a few unlucky westerners are amongst the dead.
The 'transcript' of radio communications published in today's Telegraph would turn Fursty's professional alarms on in double time. Then you realise it's been translated into Mandarin and then English by machines or people who don't realise that height/altitude/flight level are different conepts.
Last edited by: Bromptonaut on Sat 22 Mar 14 at 23:18
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>> I just wonder if it is not time to accept that the plane and its
>> human crew are gone and the cause may never be known.
Not nearly. It took almost two years to find AFR447. Granted, MH370 looks even more difficult.
en.wikipedia.org/wiki/Air_France_Flight_447
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>> Not nearly. It took almost two years to find AFR447
No it took a few days to find wreckage for AFR 447. It took 2 years to locate and recover the black boxes.
And where the AF flight came down was on the intended flight path. Compare with the intended flight path to China for this flight!
Last edited by: rtj70 on Sun 23 Mar 14 at 01:20
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True. I can't see it being abandoned for some time just the same.
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Sarah Palin has had the answer all along.....:
tinyurl.com/lbtvws4
Just imagine. This woman wanted to be the second most important person on the planet.....
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Scary lady, her concept of aircraft matches Z̶e̶r̶o̶ Kevins concept of submarines. :-)
Last edited by: Uncle Albert on Mon 24 Mar 14 at 09:42
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A true flight of fancy on her part...:-)
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she has a better grasp of what Doppler shift is than you do tho.
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>>Sarah Palin has had the answer all along.....
You know that this wasn't actually true, right? Just made up to be "funny".
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I'd vote for Sarah just 'cos she's a GILF!
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Investigators are focusing their efforts on discovering who called Malaysia Airlines flight 370’s pilot shortly before takeoff using a prepaid cellphone purchased with a false ID, Britain’s Daily Mail is reporting.
According to the report published late Saturday night, “The captain of missing Malaysia Airlines flight MH370 received a two-minute call shortly before take-off from a mystery woman using a mobile phone number obtained under a false identity.”
The call was one of the last made to or dialed from Captain Zaharie Ahmad Shah’s cellphone on the day of the flight now more than two weeks ago, the Daily Mail reported.
“Investigators are treating it as potentially significant because anyone buying a pay-as-you-go [prepaid] SIM card in Malaysia has to fill out a form giving their identity card or passport number,”
A source that is NOT the Mail says
The captain is allegedly estranged from his wife and the co-pilot, having done 6 sorties in the flight simulator was on his first "Live" sortie
Last edited by: Meldrew on Mon 24 Mar 14 at 12:59
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After the September 11th Al Qaeda attacks on the U.S., Malaysia instituted an anti-terrorism policy under which every purchased phone number is registered to an individual, the Daily Mail noted.
When police tried to locate the person who called the pilot of the ill-fated flight, they instead arrived at a store that sells SIM cards in the Malaysian capital, Kuala Lumpur. There, they learned it had been “very recently” purchased by an individual who gave a woman’s name, but was later discovered to have been using a false identity.
The Daily Mail wrote, “The discovery raises fears of a possible link between Captain Zaharie, 53, and terror groups whose members routinely use untraceable SIM cards. Everyone else who spoke to the pilot on his phone in the hours before the flight took off has already been interviewed.”
On the other hand, the use of a prepaid SIM using a false identity would not necessarily point to terrorism. The Daily Mail noted that political activists in Malaysia have in the past masked their identities when purchasing SIM cards of concern their phones are being bugged by the government.
FBI computer analysts are now probing the hard drive from Captain Shah’s home flight simulator. They are trying to recover deleted files on the device which is now at the FBI lab in Virginia.
The Daily Mail also reported Sunday that Malaysian investigators are set to question the pilot’s “estranged wife” after waiting two weeks “out of respect” of her situation of stress.
The paper reported that the couple was separated, but had been living in the same house. They have three children.
According to other reports, for example in Australia’s Sydney Morning Herald on Sunday, Shah was “a happily married pilot with three adult children.”
An unnamed source told the Daily Mail, “Faizah has been spoken to gently by officers but she has not been questioned in detail to establish her husband’s behavior and state of mind in the days leading to the incident.”
The gentle approach with a potentially key witness has reportedly irked FBI investigators assisting with the probe.
“The whole world is looking for this missing plane and the person who arguably knows most about the state of mind of the man who captained the plane is being left alone,” a source close to the FBI team told the Daily Mail. “If we want to eliminate the chief pilot from the inquiry, we must interview her in detail to find out what his state of mind was.”
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We now know where, I wonder if we will ever know why?
My thoughts are with the families of those lost.
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One of the readers comments in Daily Mail.
In a forthcoming film, a plane is involved in a mid-air collision with an unmanned drone returning from a routine spy mission. Communications are knocked out by an electrical fire which later takes out the transponder The pilot flying the plane is killed and slumps back in his seat taking the plane up to 45000 feet. Despite depressurisation, his colleague manages to tap new coordinates and a much lower altitude into the automatic pilot before losing consciousness, hoping that he will revive at 5000 feet and be able to return the damaged plane to its departure point. Sadly, like the passengers, he never revives and the plane flies southwards until it runs out of fuel. An oil rig worker witnesses the drone crashing into the sea. The owners of the drone, in an attempt to cover up the accident, dispatch ships, ostensibly to search for the missing plane but in reality to recover the drone.. Satellite images reveal the plane's crash site and the race is on to recover the black box first.
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We just might not find out the why part. The blackbox recorders won't contain anything relating to the time the plane's direction was changed will they - they are on a loop and the time period too great to contain that info.
But why would anyone fly a plane with limited fuel over that ocean? They couldn't reach land surely? But if something did happen to the plane, why did it change course?
As soon as so many planes and ships were being sent to the area, it was looking like they knew where it had come down. I would imagine some of the satellite images we haven't seen have much greater detail (i.e. some detail instead pixelated images).
Could it be possible to ditch a plane in the sea, take off some 'cargo' and let it sink?
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>> Could it be possible to ditch a plane in the sea, take off some 'cargo'
>> and let it sink?
>>
No. Unless it is a 007 movie.
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>>The blackbox recorders won't contain anything relating to the time the plane's direction was changed will they - they are on a loop and the time period too great to contain that info
>>
The voice recorder is on a two hour loop.
If it was not switched off the last two hours of the flight might not give much info.
The data recorder is capable of recording the whole flight, again if it was not switched off .
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My theory is that after the initial problem one of the pilots headed for Langkawi airport, it has a long runway with no high ground on the approach. During the return while manoeuvring to line up for the approach the pilots, and maybe everyone on board became incapacitated while the plane was heading in the direction of where it has ended up.
I suspect we may never know.
Last edited by: Uncle Albert on Mon 24 Mar 14 at 16:44
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Perfectly reasonable but why no Radio communication from the aircraft? Cockpit crew have O2 masks to help them survive smoke/fumes for long enough to make a radio call plus, if it hadn't been disabled, they could put out the emergency code on the transponder as well.
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Fire damage? Your priorities may change if your backside or flight deck is on fire. But that raises the question of how was the fire extinguished, depressurisation?
Last edited by: VxFan on Mon 19 May 14 at 01:22
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Fire causing both damage to Comms kit and structural weakness sufficient to lead to explosive decompression? Failure of oxygen kit or failure of crew to don masks quickly enough?
The discussion on Pprune includes mention of an accident in the late seventies when a Beech Super King Air (a sophisticated free turbine propjet) crashed after a sortie to train for decompression went tragically wrong. Both crew died of lack of oxygen and aircraft flew on in circles gradually drifting from Devon to near Nantes when it crashed after fuel was exhausted.
www.aaib.gov.uk/cms_resources.cfm?file=/9-1980%20G-BGHR.pdf
Last edited by: Bromptonaut on Mon 24 Mar 14 at 17:59
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But where headed was not the same as the direction they'd have flown to get to Langkawi airport is it. Something or someone disabled the transponder and then they turned back.... and then headed south it seems.
Also reports of the pilot being called from a PAYG phone SIM that was purchased using false ID. A bit suspicious or coincidence?
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>> But where headed was not the same as the direction they'd have flown to get
>> to Langkawi airport is it.
That's why I said "while manoeuvring to line up for......" .
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>> >> But where headed was not the same as the direction they'd have flown to
>> get
>> >> to Langkawi airport is it.
>>
>> That's why I said "while manoeuvring to line up for......" .
But it changed course after the line up, can't do that on its own and maintain a straight flightpath.
Its final course was dialled into the autopilot or guided onto that course by hand and the autopilot took over.
If the supposed issues (fire etc etc) were that bad it didn't stop it being airworthy for hours and hours on end. It crashed where it crashed because it ran out of fuel, and it got there because someone or something guided it there. Has to be a suicide.
Last edited by: Zero on Mon 24 Mar 14 at 18:14
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>> Also reports of the pilot being called from a PAYG phone SIM that was purchased
>> using false ID. A bit suspicious or coincidence?
>>
Reported that his marriage was on the rocks, maybe no more suspicious then either a Mistress or 'professional' help with his sex life??
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You could get the pax off, according the wildly optimistic pictures on the safety leaflet in the seat pocket in front of you. Not in the Roaring Forties at the beginning of the Southern Hemisphere winter, I would suggest
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Only the difficulty of measuring these things prevents me from repeating that psychological assessment would be a good idea before granting a driver's licence, let alone a commercial pilot's licence. Everyone is talking as if a few marital or money problems would naturally send a pilot over the edge. Can this really be so? Surely not.
What do you think helicopter? Can a pilot go secretly doolally without someone noticing and referring him to the company shrinks?
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I had Sky News on as background noise this morning and was not actually watching it but heard someone say when talking about the search "There will be submarines in the area but no one will be talking about that". They will have to have a very accurate area to search for them to find the black box before the pinger battery fails.
If there is a submarine there. The Australian diesel submarines are based near Perth.
Last edited by: Uncle Albert on Tue 25 Mar 14 at 09:54
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>> You could get the pax off, according the wildly optimistic pictures on the safety leaflet
>> in the seat pocket in front of you. Not in the Roaring Forties at the
>> beginning of the Southern Hemisphere winter, I would suggest
My understanding is that the only time lifejackets on a commercial aeroplane have ever had any potential utility was the Hudson River crash. Always happy to be corrected.
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I agree that a lifejacket is of limited use, even if you managed to use one (unlikely) exposure would kill you pretty rapidly in cold water. Warm water tends to have hungry wildlife.
Last edited by: Uncle Albert on Tue 25 Mar 14 at 11:48
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Mail report includes description of how plane was located, which included use of something called the 'Doppler effect' - anyone know anything about that? :)
tinyurl.com/ogw5ros (DM)
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You would have to ask Zero and Kevin about that, they seem to be the local Doppler and signal processing experts. :-)
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UA, you need to let this go.
Or tell people where they have got it so wrong.
These endless snide comments which offer no information at all are tiresome and pointless. Such assertions as you do make seem at best to be badly worded and at worst show a complete lack of understanding of the physics involved.
And really, the whole James Bond, national secrets, "if I told you I'd have to shoot you" type rubbish is just silly. If people are as wrong as you seem to believe there's an awful lot of room to maneuver between correction and secrets.
Last edited by: No FM2R on Tue 25 Mar 14 at 12:43
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There are no secrets about Doppler, many sonar systems are in the public domain. The only "James Bond, National secret, I'd have to shoot you, (which I have not said), bit how it is used and its capabilities.
If you can't work that out that's your problem not mine.
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It's why sirens sound higher in pitch when approaching and lower when going away from you.
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I had a flight in an airship where the 'pre-flight briefing' mentioned the life-jackets. We were told they were compulsory on all commercial flights, even when the flight was completely over land. The crew assumed it was in case we came down in a swimming pool!
We were also requested not to hang cameras, binoculars, etc. out of the opening windows unless they were safely secured from being dropped!
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>> >> You could get the pax off, according the wildly optimistic pictures on the safety
>> leaflet
>> >> in the seat pocket in front of you. Not in the Roaring Forties at
>> the
>> >> beginning of the Southern Hemisphere winter, I would suggest
>>
>>
>> My understanding is that the only time lifejackets on a commercial aeroplane have ever had
>> any potential utility was the Hudson River crash. Always happy to be corrected.
Absolutley. Its a complete waste of time weight and expense carrying floatation equipment.
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Zero: Its a complete waste of time weight and expense carrying floatation equipment.
Not so. Many airports are built near bodies of water where large areas of cheap flat land were available. Most crashes occur during take off or landing. So if the aircraft ditches over water close to shore, floatation equipment helps keep surviving passengers, well, afloat, until they can be rescued.
Further into the journey, its the fall from 35,000 feet would cause the biggest problems...
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Good point Gromit, There is a small river running parallel to the runway on the opposite side from the terminal at Edinburgh airport. There is life saving equipment for water rescue located inside the airport perimeter fence near the emergency access gates.
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Nearly all successful ditchings have been in relatively shallow water such as rivers or lagoons where rescue vessels are close at hand. As Gromit says, in those cases life jackets etc will help.
Landing on water inevitably causes severe damage to the airframe. Even in the most celebrated case, the US Air A320 ditched into the East River impact damage limited the time the machine could stay afloat. The Ethiopian 767 ditched off the Comores with 125 deaths from 175 on board is much more representative of likley outcomes in open ocean.
Guy from Inmarsat interviewed on radio last night was comparing shipping, where merchant vessels regularly report their position by satellite with aviation. Such surveillance for aircraft might he said cost as little as a dollar and hour wholesale.
Sounds cheap until you multiply it my number of hours flown Ryanair's fleet in a year.
Bearing in mind this is first case of its type (the AF A330 went down broadly on its planned route) the economic arguments don't really stack up. Even on long over water routes such as the North Atlantic aircraft report their position by HF radio at regular intervals - every 10 degrees of longitude over the Atlantic.
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>> Sounds cheap until you multiply it my number of hours flown Ryanair's fleet in a
>> year.
Sounds cheap again if you divide it by the number of passengers though.
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>> >> Sounds cheap until you multiply it my number of hours flown Ryanair's fleet in
>> a
>> >> year.
>>
>> Sounds cheap again if you divide it by the number of passengers though.
...or compared to the cost of the fuel being used.
Last edited by: Focusless on Tue 25 Mar 14 at 14:54
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>> Nearly all successful ditchings have been in relatively shallow water such as rivers or lagoons
>> where rescue vessels are close at hand. As Gromit says, in those cases life jackets
>> etc will help.
Hasn't happened often enough to draw that conclusion. There have been very few successful ditchings where floatation equipment was used.
Last edited by: Zero on Tue 25 Mar 14 at 14:54
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The dual use equipment is useful, door slides / liferafts.
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I can't understand why the crew should be able to over-ride the plane's transponders. Surely they should be tamper proof?
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>> I can't understand why the crew should be able to over-ride the plane's transponders. Surely
>> they should be tamper proof?
>>
In case of a fault or fire? Even your car has fuses and circuit breakers.
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>> In case of a fault or fire? Even your car has fuses and circuit breakers.
It cannot be 'tamper proof' either as the pilot will certainly need to use the its control panel at various times in the flight.
The four digit 'squawk' code provided as part of the route clearance will need to be entered before take off. On first contact with en-route ATC the pilot be asked to operate an ident switch on the transponder which makes the aircraft's blip on the radar more conspicuous. As only 4096 codes are available worldwide he's also likely to have to change it crossing international boundaries.
There are special codes for emergencies and it used to be necessary to put the transponder to standby when changing codes in case an emergency code was transiently selected. Modern installations though use a keyboard rather than rotary knobs.
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>> >> I can't understand why the crew should be able to over-ride the plane's transponders.
>> Surely
>> >> they should be tamper proof?
>> >>
>>
>> In case of a fault or fire? Even your car has fuses and circuit breakers.
They can electrically isolate more or less everything that has power on the plane. The common stuff on a 777 is on a panel over their heads, and some of the less common stuff is in a hatch in the floor.
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The life jackets will be part of the safety culture of flying, there in case. Only large aircraft ditching successfully I can think of is the Nimrod (XV666?) in the Moray Firth on take off. It hit a flock of birds, the airframe was salvaged and brought back into service.
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Can we have a new thread mods? This is a bit long for those on a phone.
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>> Can we have a new thread mods? This is a bit long for those on a phone.
>>
Plus a new heading ?
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>> >> Can we have a new thread mods? This is a bit long for those
>> on a phone.
>> >>
>> Plus a new heading ?
>>
I will start a new thread,
MH370
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Dreamliner problems. - Meldrew
