This missing plane..

[BiggestNizzy]

Where's Pete when he's required?

Carving out a new career on BBC Alba.

[Gareth]

Real life LOST

[flyingscot68]

From The Telegraph:

"our correspondent in Kuala Lumpur, says villagers from near Marang, on Malaysia's eastern coast, told police they had heard a "loud and frightening noise" at around 1.20am on Saturday morning.

Alias Salleh, a 36-year-old lorry driver told Malaysia's The Sun Daily, he and friends had run towards the source of the noise, "but did not see anything unusual".

The noise sounded like "the fan of a jet engine," Mr Salleh added.

Mohd Yusri Mohd Yusof, a 34-year-old villager, said: "My friends and I heard the ringing noise for about two minutes."

Sounds like it's in the jungle somewhere if the above is true - hope so, there might be hope for some of the passengers yet.

[Mikie711]

A[[apparently the passengers mobile phones are still working so doesn't sound like a over water event.

[sendmyusername]

Agree with the fact that it took them two years to find the 2009 flight. Don't you need to be within two miles of the transponders to trace the signal ?
The fact the phones are still ringing is puzzling me, can't they pass a satelite overhead and triangulate without the need for the need for the mobiles location ? (best do it before the battery runs out)
My guess it was off course and crashed on land (but would have expected fires at least)
Might be because america needs an excuse to invade iran for it's oil seeing as it's towed the line on the nuclear deal ..
Just today they are now blaming lockerbie on the iranians from "new evidence" (i.e. The old evidence which didn't suit them at the time)
Seems strange there is no trace.

[woody]

Phones were ringing in the day after it went missing. My understanding is 19 families got phones to ring but by the time they passed this information on to the Airline, the phones were not ringing.

[neil]

I think the phones are a red herring. I think in some parts of the world you'll hear it ringing when the networks trying to find the phone. Anyway, if the phones had been on the network they'll be able to tell which tower the phones spoke to last and when.

[pete]

After talking it through last night with a couple of colleagues we have no ideas.
I'm leaning towards tut's theory - possibly involving an aircraft carrier.

[BiggestNizzy]

I think the phones are a red herring. I think in some parts of the world you'll hear it ringing when the networks trying to find the phone. Anyway, if the phones had been on the network they'll be able to tell which tower the phones spoke to last and when.

Friend of Sister gave her daughter an old PAYG phone to play with and she managed to dial 112 it took the police less than 15 minutes and y were chapping her front door (old phone was registered to a different address)

[tut]

I do not think enough attention has been paid to the lack of a radar signal from a solid object if it had still been airborne.

Stealth aircraft were built so that they only produced a very small radar signature, but not none at all. A commercial aircraft produces a big blob which will show on the ATC screens especially at that altitude, unless of course the aircraft broke up.

tut

[graeme]

Yeah, I don't understand that either. Goes against my very very basic understanding of primary/secondary radar. Turning off a transponder does bugger all but hide your ID and, I think, you lose collision avoidance and other secondary radar-based services. It doesn't vanish you from the skies on the green screen with the bleeps and the sweeps and the creeps.

Also, is there a flaw in the handover process between controllers? It's up to the pilot to switch frequencies and say hello to the next controller, but do the controllers ever check that the handover was successful? Is the border between controlled spaces THE ideal place to vanish, or are there systems that protect against leaving one and never contacting the next?

Pete, if you get a minute, I would love to know how the hand-off works from one controller to the next, and what happens on the ground (alarms etc?) when a transponder stops transpondificating. General questions, not incident specifics.. wouldn't ask you to professionally speculate, especially if you're crazy enough to think an aircraft carrier is involved.

[Rag_It]

I have very little to add, except it is a story that has kept me incredibly interested..

1. In this day and age that a feckin huge plane like a Boeing 777 can just disappear. (Wasn't aware it took them 2 years to find the AF flight)
2. Hope that they find it so that families can get some answers and closure.

I'll go as far as saying bollox to any conspiracy theories - i too suspect it's in the jungle somewhere and we just have no idea about the sheer scale of the landmass that it was flying over.

Interesting article here:- http://www.dailymail.co.uk/sciencetech/ ... 0-jet.html

Dave

[pete]

Yeah, I don't understand that either. Goes against my very very basic understanding of primary/secondary radar. Turning off a transponder does bugger all but hide your ID and, I think, you lose collision avoidance and other secondary radar-based services. It doesn't vanish you from the skies on the green screen with the bleeps and the sweeps and the creeps.

Also, is there a flaw in the handover process between controllers? It's up to the pilot to switch frequencies and say hello to the next controller, but do the controllers ever check that the handover was successful? Is the border between controlled spaces THE ideal place to vanish, or are there systems that protect against leaving one and never contacting the next?

Pete, if you get a minute, I would love to know how the hand-off works from one controller to the next, and what happens on the ground (alarms etc?) when a transponder stops transpondificating. General questions, not incident specifics.. wouldn't ask you to professionally speculate, especially if you're crazy enough to think an aircraft carrier is involved.

I wish I'd been following this more closely now! (and you know that I'm better at speculating wildly about things I know very little about? OK a sort of a pocket guide. Maybe apocryphal. May contain errors.)

Primary radar coverage is out to about 100 miles from the radar head (line of sight remember). Modern primary radar pictures are normally processed so you are seeing a "digital" rendition of the analogue primary data. As such the planes no longer look like the crescent shaped smear on the screen, which as Tut said used to get bigger if the plan was higher. It's just a computer generated cross. It also filters out stuff that we don't want to see (weather, birds etc). The radar is recorded, that's mandated, but I don't know if the raw data is recorded as well as the processed picture. So it very unlikely you would see a cloud of debris if there was a massive failure.

As for co-ordination between sectors.

For all flights within controlled airspace an aircraft requires a clearance. That clearance is obtained from a controller who is in charge of a sector of airspace. That sector is normally defined by horizontal limits, but they are sometimes vertical too. Let's just consider horizontal ones for now. Imagine a map with boxes all over it - each box is a sector, the bigger the box the quieter the sector.

Once an aircraft starts the flight plan, which contains the aircraft's requested route, is activated and all the sectors through which the aircraft will pass receive details of the flight, so each sector is expecting the flight. As the a/c proceeds from one sector to another the controller phones ahead to co-ordinate with the next sector how that sector would like the a/c, this co-ordination will be done by phone along the lines of "<sector name> request clearance <a/c callsign> he's at flight level 330 estimating <reporting point> at <time>." The receiving controller will already have details of the aircraft and will be expecting it and issues a level or other restriction, perhaps a heading, based on other traffic.
Finally as the aircraft approaches the sector boundary the controller phones the other controller and gives a handover (effectively "can you see the <a/c callsign> at <location> at <altitude> etc").
Aircraft route by means of reporting points, points at which they are required to make a report. Except in a radar environment we no longer require them to make a report.

But then we streamline a bit, maybe all departures from an airfield are accepted climbing to the same level and no longer require an individual phone call. Or we do silent handovers between sectors, after all if the a/c is transponding we'll be able to see it and co-ordination has already been affected. Or there are electronic systems which reduce or remove the need for the phone calls entirely.

If an aircraft stops transponding there is no alarm - but why would there be? We are talking to the pilot on the radio, he'll tell us/we'll notice. PLus they do occasionally drop out, secondary and primary heads are not always co-located so they have different coverage etc etc.

But there are a lot of non-radar environments still (outside the UK) where aircraft report at certain reporting points, make good their time for the next point and ATC make sure they don't arrive at the same time and at the same level as another plane. If the aircraft was to suffer a catastrophic failure in between these points then it might be a while before ATC noticed, when they do ATC commence overdue action and start the search.



Also remember it's not like one ATC unit can call up the radar feed of every other unit. Some units have more than one feed, the centres have loads, but even they can't call up the radar feed of an adjacent centre. So that search process might involve many phone calls, especially if it is near an international FIR boundary - possibly the aircraft was flying in a non-radar environment but they have been looking through everyone's radar feeds to see if anyone can see it. Akin to going through CCTV footage when someone goes missing - whilst there might not be a camera on the street maybe one in a shop could see the street...

Hope that made sense.

[tut]

Great to hear an ATC's complete run down on the procedure Pete, I know the basics and have sat in many Control Towers, but that only gives me a partial overview. However as an ace pilot along with an ace controller, we should have it covered.

Do you have any explanation though that is baffling me as to how the transponder coding and the primary radar return could go off screen at the same time, other than a disintegration into component parts?

tut

[pete]

Do you have any explanation though that is baffling me as to how the transponder coding and the primary radar return could go off screen at the same time, other than a disintegration into component parts?

tut

From what little I've seen on the news some the communication with the media seems a little inconsistent to say the least. Because of that speculation isn't even really possible because there aren't any facts on which to speculate!

But as a random guess catastrophic failure of the aircraft - when it disappeared from radar it fell into the sea. But like I said I know nothing!