UKC

When MA370 went down lots of people were astonsihed that some basic data wasn't streamed very frequently to ground - GPS location, altitude, airspeed.

Here we are again - although luckier this time - scanning largew (200 NM by 200 NM) areas of seas and hoping to spot wreckage.

Why? It can't be either difficult or expensive to gather and send the data.

In reply to JJL:

The job of accident investigators requires the piecing together of as many physical components as possible.

In reply to JJL:

Err, when the data stops how do the searchers know if the plane fell out of the sky in a load of bits OR glided 100miles in an unknown direction?

In reply to JJL:


Good point, but it would be very costly to fit such systems to all commercial airliners - not forgetting the great cost of having whole fleets of planes sit on the ground while they are fitted. I think at the moment [since MH 370] minds are very focused on missing airliners - that was a very unusual event.

I'm not against your idea of course: just looking for some perspective. Perhaps they could be fitted to all new planes in future?

Edit, I am a complete non-expert in aviation (this added after seeing comments on another thread)

In reply to JJL:
Don't they already? I have an app on my ipad which shows where planes are in real time.

In reply to jimtitt:


If you had the telemetry you would know the direction. If it was gliding, the telemetry would still be sending. Would narrow the area rather.

In reply to abseil:

Why would it be costly? A few thousand quid at very most.
Planes are out for scheduled maintenance quite frequently; do it then.

In reply to andy:


Nope. Which is why there was all the forensic analysis of ping time differentials to get MH370 mapped to the Southern Ocean. Your ipad is probably using radar data?

In reply to mypyrex:


Yes - I'm talking about finding the plane in the first place so you know where to look for bits.

In reply to JJL:


OK, thanks for your reply, and good point - let me phrase it another way though - what is the actual cost, and are airlines willing to pay for it? (I'm not asking you yourself, just thinking out loud of course)

In reply to JJL:

Google ACARS. This basically already exists, but as always, it's not as simple as you might think. There's a whole bunch of reasons as to why an it might fail or not be totally accurate/useful.

In the example of MH370, the primary ACARS system failed but there was a secondary one, which is why we have a vague idea of where it might have crashed. If the ACARS fails, that doesn't mean the plane hasn't kept on travelling for quite a long way. From 30,000ft, most commercial airliners will glide for around 100 miles or so. So if it lost electronics, it could have kept on going for a while before crashing.

http://www.salon.com/2014/03/19/7_technologies_for_tracking_or_losing_airpl... - this article is a good summary.

In reply to JJL:

I keep wondering the same and was one of the OP's "astonished" when MH370 disappeared. I have one of those wee Spot trackers which can send out it's location every ten minutes. It uses GPS and the satellite phone network so provided it has a good view of the sky, which seems a reasonable assumption for an airliner, it works pretty well. No need for radar coverage or transponder operation. So my suggestion is we take one of these for each passenger jet and gaffer tape it to the roof. That way no crazy pilot with a grudge can turn it off. Cost estimate about £100 a unit including batteries and gaffer tape.

In reply to JJL:

1. Satellite comms are not a cure-all.

2. Europe and the North Atlantic are a tiny portion of planet Earth. Since that is all that the influential populations know about, it can escape their notice that the other bits are BIG.

3. Some of the thing that tell you where ships and planes are around here are terrestrial-based VHF and not satellite-based.

In reply to JJL:

I love UKC. Climbers providing piercing insight into problems that whole industries around the world struggle with.

Somewhere in a parallel universe on a site called UKairtrafficcontrollers.com the air traffic controllers are dispensing their armchair insight into how to predict exactly when winter conditions will be in on any given route; it's simple, just read the forecast and work it out, surely?

In reply to JJL:

It sounds horrific..

If as suggested now the plane landed on the water.. like the Hudson landed, so no beacon, then sunk.. that is my worst nightmare... obviously it was a slow enough descent for people to know.. just awful.

In reply to nickinscottishmountains:
The discussions on PPRuNe (Professional Pilots' Rumour Network) are always worth a read on this kind of thing.

Edit: and they appear largely to be talking about the stall theory.

Neil

In reply to nickinscottishmountains:

That'd be quite funny... if I'd actually done anything other than ask a question. I was hoping that someone suitably informed might explain the answer - as the obvious reasons don't (at first blush) stack up.

In reply to JJL:

Expensive because you need satellite coverage for the sea which is a moot point because we have this. Plus some a320 have WiFi via a Sat link so it's there.

Difficult because everyone needs to agree and use it. Current example would be IFF transponder freq which is still classified(I think) in the USA even though everyone uses it. Try working with bureaucracy like that. There are many many many tests to qualify something for flight.

Flight radar uses info sent via ground and sat link, mh370 was tracked using the Doppler effect on a Sat link, ping time gives distance but the Doppler shift showed it was traveling south. Rolls Royce use this to monitor in realish time. Tracking using this was a first and is dependant on the atmosphere. At the end of the day flight radar isn't tracking via a radar so you still need a connection to your plane like other systems. Flight radar is just another way to show position which is good but it's never going to be radar.

These systems cost way more than a grand.

In reply to itsThere:

Intresting stuff.

Is it truly *that* expensive to pipe out a small datset at fairly frequent intervals via satellite?

As you say, the satellite cover is there and many planes now let you make satellite calls - I could ring through the data if that helps?

In reply to IainRUK:


That is highly unlikely. I would read nothing into the non-functioning of the ELT. While nothing is impossible there is always a load of utter rubbish spouted in the media in the early days after these sort of events. ELTs have a very low probability of functioning in an accident, usually the antenna is destroyed in the crash or it's underwater where they don't work.

In reply to JJL:

Do we even need it, we can do it with the transponder. In this case there would be no difference, we lost radio contact 2min after it had asked to climb to avoid a storm. To me that says why didn't we avoid the storm like many other planes do or not fly over a known conflict zone. No matter how good your system is that reports the data it didn't bring the plane down. The plane should not crash anyway.

With regards to this plane, finding the wreckage has been limited by weather and your last known position from 30,000ft gives a wide area. Even with all that they will find the black box sonar soon enough.

In reply to Daysleeper:

Still (if true) the people did have time to get life jackets on supposedly.. I'd much rather not know anything about what was going on..

In reply to JJL:
Bit of a name change to answer this question (popular on mums net apparently)

It really is a fair question I'll have a go at answering it...

There are 190 (ish) States signed up to the International Civil Aviation Organisation (ICAO) (a bit of the UN based in Montreal) and they set the standards and recommended practices (SARPs) for states to then get their airlines to adopt. To change SARPs requires a lot of negotiating and what seems obviously a good idea to one State can be obviously a bad idea to another. People I know suggest it takes roughly 10 years to change a SARP especially if the idea is novel or technically complex. 10 to 15 years ago the tech to track lots of aircraft in real time far offshore didn't really exist at anything like a reasonable cost/benefit to persuade the States that it needed to be done. Of course many operators chose forms of data links, satcoms etc for various commercial reasons and 2009's AF447 had some data with appended position information downlinked from the maintenance reporting system.

Tracking aircraft over land and in areas close to the coast (say 100nm) is done by ground based Radar often these days aided with data linked GPS position reporting by VHF (picked up by web tools like FR24) and finding crashed aircraft in those environments is considered simple(ish). The current search off Indonesia appears to have been more limited by the weather than any broad uncertainty over location.

Set against the cost of tracking is the relative risks, (beware statistics, those of a low boredom threshold should skip ahead)
Airbus reckon in 2013 there were 0.21 fatal accidents per million flights and the global long haul fleet is dominated now by the A330 and Boeing 777 where the rate is about half that (0.11) . So roughly 1 in 9,000,000 long haul departures will result in a fatal accident. The cruise phase (the bit where you might be out of range of ground based aids) accounts for about 12% of all fatal accidents. So we roughly 1 in 75.8 million departures will result in a fatal accident in the cruise. Of course the majority of routes are in fact over the land whether long haul or not so even a cruise accident we probably know where the aircraft was. I can't quite do the maths for the % of cruise phase routes that are beyond land based aids but a guestimate was that about every 10 years or so we might lose a long haul aircraft with enough uncertainty to need to spend a lot of time/money looking for it.

So how much is "a lot" AF447 cost in the region of $100 million to find and recover, seems like a lot but it's about the list price of a new A330. Equally it should have been less but in the initial search too much confidence was put on one assets capabilities which turned out to be crap.

Overall only in the last few years is the tech reasonably available to track or datalink lots of data and the cost benefit is still mainly against it from a purely safety point of view but it is coming as part of a package other upgrades and changes.

In reply to IainRUK:


Subsequently been denied by Indonesian search team, confused report was passenger found and later life jacket found.
Tatang Zaenudin, the deputy head of operations at Indonesia's search and rescue agency said ; "There is no victim that has been found wearing a life jacket. We found a body at 8.20 a.m. and a life jacket at 10.32 a.m. so there was a time difference. This is the latest information we have,"

In reply to Daysleeper:

ahh thanks..

In reply to ToraToda:

Thank you

Understood, but could a carrier not simply decide unilaterally, the same way they pick an entertainment system?

Fair enough


Excellent. However the same logic would say we should shrug and say "it happenstance" rather than spend £70m searching (and a heap more for 370?)


Good news!

In reply to nickinscottishmountains:

It can be done, easily, it just costs a bit:


http://www.independent.co.uk/news/world/americas/after-airasia-and-mh370-fl...

In reply to JJL:


Yes and several do, though no one system has truly global coverage. There is in everything a cost benefit analysis.

Harsh though this sounds there is a school of thought that says, given what we already know, there is no safety purpose in continuing the search for MH370. The 777 is so statistically safe that one loss for reasons unknown makes little difference its risk profile.

In reply to nickinscottishmountains:



Thanks for that, you've got my thoughts in a nutshell.