Malaysia Airlines flight MH370-Updates and Discussion

SpaceTime

Calina wrote: »

777 has two GPS receivers on it and a transponder which reports its positional information.

Additionally, both its data recorderss should be pinging their position, even under water.

Still seems very odd then that they can't be located by now.

Do they ping their position in a way that's detectable by satellite for example? Or, does a search aircraft have to fly overhead?

Surinam

cml387 wrote: »

Although widely used in avaiatgion, GPS is a bit of a problem for the aviation industry because it is not controlled by the ICAO.

Since it's a US (military) system, the US could degrade or encode the system at any time.Then you'd be in trouble.

Isn't there that Glonass system that Garmin have been mixing into their conventional gps watches and odometers?

Kavs8

eatmyshorts wrote: »

One word... cost. And today's passenger is so cost sensitive, they will refuse to pay for it.

Can you stop spouting nonsense? You are in no position to say such a thing. The aircraft is equipped with 3 high frequency signals they are yet to be picked up - they will find them.

fits

cml387 wrote: »

Although widely used in avaiation, GPS is a bit of a problem for the aviation industry because it is not controlled by the ICAO.

Since it's a US (military) system, the US could degrade or encode the system at any time.Then you'd be in trouble.

Even the degraded signal would be useful no? It used to result in inaccuracies <100m? (as far as I remember.)

sopretty

I agree. You'd imagine, that the last identified location of an aircraft would be a close enough indication of where a wreckage might be. It's like as if (excuse my ignorance of the geography of that end of world), a plane went missing between Ireland and England and people started searching the Irish Sea, and then they decide, 'actually - no - we should start looking in the Atlantic'.

Now, I'm not sure if my analogy is even remotely analogous lol, but that's what it's all sounding like to me! Please feel free to correct me if I'm wrong!!

Surinam

MYOB wrote: »

Flightradar24 doesn't use radar despite the name, it uses its own private ADS-B receiver network. ADS-B gets its location from GPS.

How do you propose a GPS unit both works underwater and sends a signal to a satellite from underwater, for a prolonged enough period to be of use? Remember for starters that GPS is one-way.

I'm obviously not an expert but if it is sending out constant pulses just before going under water then surely that would give a useful indication of where in the sea floor it (and the rest of the plane) would likely be??

SpaceTime

cml387 wrote: »

Although widely used in avaiation, GPS is a bit of a problem for the aviation industry because it is not controlled by the ICAO.

Since it's a US (military) system, the US could degrade or encode the system at any time.Then you'd be in trouble.

That's why the EU's been spending €5bn on Galileo.

L1011

Surinam wrote: »

I'm obviously not an expert but if it is sending out constant pulses just before going under water then surely that would give a useful indication of where in the sea floor it (and the rest of the plane) would likely be??

Just how long do you think it takes for something to fall 35000 feet?

SpaceTime

MYOB wrote: »

Flightradar24 doesn't use radar despite the name, it uses its own private ADS-B receiver network. ADS-B gets its location from GPS.

How do you propose a GPS unit both works underwater and sends a signal to a satellite from underwater, for a prolonged enough period to be of use? Remember for starters that GPS is one-way. The satellites do not know where you are, despite the massive misconceptions that they do - your receiver calculates that itself.

Perhaps by pinging something like the Iridium satellite phone network?

The GPS unit would need to know the last known coordinates and automatically transmit them as soon as it began a rapid decent or if the cabin pressure drops below a set figure, or if it loses connection to the aircraft systems i.e. before it was under water.

Surinam

MYOB wrote: »

Just how long do you think it takes for something to fall 35000 feet?

Not that long I'd imagine, but if the beacon (like a black box recorder) could withstand a mid air breakup/explosion then it could keep sending out a signal until it went under water, no?

keith16

sopretty wrote: »

I agree. You'd imagine, that the last identified location of an aircraft would be a close enough indication of where a wreckage might be. It's like as if (excuse my ignorance of the geography of that end of world), a plane went missing between Ireland and England and people started searching the Irish Sea, and then they decide, 'actually - no - we should start looking in the Atlantic'.

Now, I'm not sure if my analogy is even remotely analogous lol, but that's what it's all sounding like to me! Please feel free to correct me if I'm wrong!!

The Irish sea is three times smaller than the gulf of Thailand. It takes 15 or so minutes to fly across the Irish sea. Less at cruising altitude.

brandon_flowers

Some people are massively underestimating what is involved here. A plane travelling probably 10 miles every minute is missing in the largest sea in the world. Every minute adds 10 miles to the radius of the search. After 1 minute it is 157 sq miles of area, after 5 minutes it is 3925 sq miles of area assuming no turn is greater than 90 degrees left or right and discounting the area the plane has just passed over.

L1011

Surinam wrote: »

Not that long I'd imagine, but if the beacon (like a black box recorder) could withstand a mid air breakup/explosion then it could keep sending out a signal until it went under water, no?

It'd be of zero practical use - it won't give any more detail than what they already have

SpaceTime wrote: »

Perhaps by pinging something like the Iridium satellite phone network?

L band doesn't travel through water fantastically well.

Kavs8

People are comparing iPhones and Boeing 777 aircraft?

The lack of knowledge people are displaying is ridiculous on this forum, foreword research before positing goes along way.

Family members could be reading this forum and getting the impression the aircraft had zero hope of being found because people do not know what they are talking about.

The aircraft has 3 of the worlds most sophisticated trackers and once identified they will immediately be recovered,

Now people are contributing well to this forum but throwing out waffle like "they don't have trackers because of cost" just what sort of industry do you believe you are commenting on?

Please shut up before spouting waffle.

SpaceTime

We really need a search and rescue satellite network for this kind of thing.
Maybe such a function could be built into future communications satellites so they could perform a dual purpose?

i.e. some kind of a sat network capable of picking up quite weak signals from a new generation of black boxes. It could also serve a purpose for other emergency situations like maybe for commercial shipping, very remote locations etc.

homerjay2005

would the black box not be emitting a signal?

sopretty

keith16 wrote: »

The Irish sea is three times smaller than the gulf of Thailand. It takes 15 or so minutes to fly across the Irish sea. Less at cruising altitude.

But surely the last known radar location could narrow down the search area? Sorry if these are stupid questions, as I haven't a clue, but I'm finding it hard to comprehend, how a plane had exact and precise last known co-ordinates, and yet can't be found!!! I'm sure there is someone, who could calculate where the debris might be found, and then factor in currents etc. to estimate where the debris would end up??

L1011

sopretty wrote: »

But surely the last known radar location could narrow down the search area? Sorry if these are stupid questions, as I haven't a clue, but I'm finding it hard to comprehend, how a plane had exact and precise last known co-ordinates, and yet can't be found!!!

Because its last known location is 35000 feet up in the air over water, which moves.

sopretty wrote: »

I'm sure there is someone, who could calculate where the debris might be found, and then factor in currents etc. to estimate where the debris would end up??

There is and they already will have, a day and more ago at this stage.

There is more than sufficient signals being emitted from kit on it to enable it to be found but it is never, and never will be an instant process.

Calina

sopretty wrote: »

But surely the last known radar location could narrow down the search area? Sorry if these are stupid questions, as I haven't a clue, but I'm finding it hard to comprehend, how a plane had exact and precise last known co-ordinates, and yet can't be found!!! I'm sure there is someone, who could calculate where the debris might be found, and then factor in currents etc. to estimate where the debris would end up??

1) it landed in water and potentially not intact and water moves. So it will have drifted from its last known location.

2) it may not be intact and could, perhaps, be in a lot of tiny pieces.

3) yes there is but that still does not give you a pinpoint option on where to search. So there is a searchbox.

____________________

It seems to me that there are chronic underestimations of how hard it is to find something which has disappeared in a body of water and chronic overestimations on what we are at this point capable of.

____________________

kona

sopretty wrote: »

But surely the last known radar location could narrow down the search area? Sorry if these are stupid questions, as I haven't a clue, but I'm finding it hard to comprehend, how a plane had exact and precise last known co-ordinates, and yet can't be found!!! I'm sure there is someone, who could calculate where the debris might be found, and then factor in currents etc. to estimate where the debris would end up??

The aircraft broke up at 35,000 ft over the sea , the debris will be spread over a huge area and at this stage under the sea.
I'm sure they have a search radius set up.

Take for example the spread of debris when Columbia disintegrated, this would be smaller scale but then again the area is smaller too.

Surinam

MYOB wrote: »

It'd be of zero practical use - it won't give any more detail than what they already have
.

Forgive me my ignorance here but how could it not be useful to know exactly where the plane went into the water? At the moment all they seem to have is a vague idea about its coordinates (@35,000feet) when it lost contact. My point is about the possibility of designing a gps beacon that can withstand mid air explosions (just like a black box) and emit constant co-ordinates signal until going underwater.

SpaceTime

It's just surprising given what *should* be possible with more modern kit and with a satellite network.

Clearly they haven't got one though.

The aviation industry takes very cautious approaches to new technology though. They're not going to jump onto technologies that they can't be 100% sure of when they have very tried and tested systems that are fully validated with decades upon decades of experience behind them. So it wouldn't surprise me that they're not using bleeding-edge technology. In fact, I'd be horrified if they were relying on it.

sopretty

MYOB wrote: »

Because its last known location is 35000 feet up in the air over water, which moves.



There is and they already will have, a day and more ago at this stage.

There is more than sufficient signals being emitted from kit on it to enable it to be found but it is never, and never will be an instant process.

Thanks for answering my questions. I don't mean to take down the tone of the thread or anything by asking stupid questions. It's just hard for me as a 'lay person' to comprehend a lot of this. Maybe I should just keep my questions to myself lol and read the more informed posts. I'm curious though and find it hard to keep my mouth shut!

L1011

Surinam wrote: »

Forgive me my ignorance here but how could it not be useful to know exactly where the plane went into the water? At the moment all they seem to have is a vague idea about its coordinates (@35,000feet) when it lost contact. My point is about the possibility of designing a gps beacon that can withstand mid air explosions (just like a black box) and emit constant co-ordinates signal until going underwater.

The likelyhood of a standalone unit having had time to generate an accurate GPS location in the time between the last known from the aircraft and it entering water is, to put it bluntly, nil.

Generating an accurate GPS fix is not instant. We already have the last known position of the aircraft. Back of a cornflake box maths suggests it'll take 45 seconds to a minute for something to fall from that height, potential terminal velocity nonwithstanding but it has been many years since I did Applied Maths and I'm probably wrong.

eatmyshorts

Kavs8 wrote: »

Now people are contributing well to this forum but throwing out waffle like "they don't have trackers because of cost" just what sort of industry do you believe you are commenting on?

Please shut up before spouting waffle.

Given the fact that I'm a current 777 Captain, I'd take a guess I know slightly more about the situation than you do.

Peppa Pig

Has any news source confirmed a break up or have any even gone with it being the most likely scenario?

Peregrine

Peppa Pig wrote: »

Has any news source confirmed a break up or have any even gone with it being the most likely scenario?

Does it matter?

Why would you want news sources to speculate without any evidence?

That's the kind of thing we don't want them to do. Most of them are absolutely clueless when it comes to aviation.

brandon_flowers

Peppa Pig wrote: »

Has any news source confirmed a break up or have any even gone with it being the most likely scenario?

Speculation, but it seems most plausible.

SpaceTime

I'm just wondering would the USAF, RAF, Russians, French, Chinese airforces etc possibly have spy planes capable of overflying that area at much higher altitudes and pick up the beacons?

They'd cover a lot more ground than a low/normal altitude aircraft

Kavs8

eatmyshorts wrote: »

Given the fact that I'm a current 777 Captain, I'd take a guess I know slightly more about the situation than you do.

Oh christ and I'm Aer Lingus current CEO, many of you lads are on the forum.