How tough are EPIRB's

An aircraft as well - most likely detroyed in the crash.

Personal Distress radio-beacons are not EPIRBs. They are PLBs (Personal Locator Beacon.) EPIRBs float, PLBs do not. A personal beacon would go down with the passenger.

Aviation ELTs (Emergency Locator Transmitters) are the class of beacons used in aircraft. They are designed to be as tough as the black boxes. They will survive the crash.

There is a problem with PLBs and ELTs however. Their signals will not penetrate a few thousand meters of salt water. The authorities are reliant on finding some reckage to locate the plane and then to track the signal emitted from the black box for sonar detection

I simply had no idea that commercial aircraft can't be tracked if their transponder (or whatever) is turned off.

just wondering if the whole story will ever be known.

Robin

I’m with you on this one, an aircraft flying into the Southern Ocean region via the Indian Ocean, seemingly going no-where, would have been of interest to defence interests in the least. Maybe I’m a bit of a cynic, but even if they did track it, whoever they are, they are unlikely to divulge as it gives up defence monitoring capabilities. The Jindalee over the horizon radar has far reaching capabilities for instance…

On EPIRBs, we were required to have one located in our aircraft, and this is a requirement for all aircraft on the Australian register that will activate on impact – at least they get to find the remains of aircraft and occupants. They are very robust as they are designed for that specific purpose.

Cheers

Landy You are touching on a very big problem with our huge coastline. Land base radar only goes to the horizon and the OTHR (Over The Horizon Radar) system I believe is looking northward. I don't even know if is even working.

So unless we have a plane or ship patrolling out that way, then we wouldn't have know they were there. And then we get to the Defence budget! Let's not go there hey.

Yes it would be nice but we can't afford it. I can't afford a guard parked out the front. I rely on a phone call to the security center if the house is breached or on fire.

Phil

Robin

Wouldn't EPIRBS be a bit like the plane's Black Box growth and development. Originally not much more than voice and a few controls. These days I saw that they get almost a full breakdown of all sensors, voice and a whole bunch of the computers flight log etc, and of course all voice.

I think that the EPIRB is also a growing technology and as the Americans have done will also extend into cars especially as the later models are so electronically "smart" and physical size of the components inside an EPIRB shrink. Isn't it true that the technology that we wonder at today has been known for decades but mainly for financial and mechanical or physical reasons has not been implemented until today.

Now just some food for thought and not necessarily OT:
They will "grow". I also wonder where it will stop though. Will we all have one on our wrist watch or embedded into the lose skin at the back of the neck. Will the doctor be able to connect to my pacemaker and give me a medical.

How long will we be able to maintain control.

Now there is a little food for thought.

Phil

Hi Phil

" Land base radar only goes to the horizon"

That would be correct if it is trying to detect something on the surface.

For airborne targets there are a number of things that affect range. If the radar is powerful enough, the two most important are the elevation of the radar and the altitude of the target.

Our civilian radars used for air traffic control have a typical range of about 160 nautical miles (about 320km) for aircraft at civilian jet altitudes (29,000 to 40,000 feet).

Even so, MH370 would not have been detected by Australian ATC radar - it was never within the range of any of them.

There are other tracking devices used by ATC when an aircraft is out of radar range, but they had been disabled on that flight. (Reason yet to be determined)

So authorities are now relying on position data supplied by the military technologies (which are vastly superior to civilian ATC technologies) of various nations. There are political inferences with that - revealing accurate location information may also reveal the intelligence-gathering capabilities of the country supplying the information, something most regimes are unwilling to do.

Cheers

Being a mere mortal I’ll preface this by saying “what would I know”.

But here is the thing. The Indian Ocean is crawling with military assets; in the air, on the surface, and under the water. These days it is all about detection, and if you look at the defence capabilities of some nations that we know of, it is astounding.

Without wanting to get into a hypothetical discussion about who might have known what, I find it difficult to conclude that it wasn’t observed and tracked by military hardware at some stage given its flight path, seemingly to no-where.

And of course, we many never know, as to reveal that a country’s defence forces observed it raises to issues, firstly they didn’t step forward earlier, and secondly, usually no country wants to highlight its capability.

Perhaps I’m a bit of a conspiracy theorist, but I suspect the real truth will never emerge…

I am leaning toward that too, Landy.

I didn't worry about the accuracy of my post. 160 kilometers in thousands is not worth the hassle of then telling the uninitiated why it would go beyond the "horizon".

Seems like there finding more and more bits by satellite. Nothing picked up yet to confirm it.

Seems more likely that the Inmarsat boffins tracing the phone "keep alive" ping were maybe on the correct track. I don't think that this Inmarsat work was done by defence technologies. But the photos were for sure. Or maybe by oceanographic and weather satellites that do not necessarily have a defence roll.

However I really don't care. But it would be nice to find the plane and give the relatives closure. That does matter.

Phil

I think one thing that people may not fully grasp is the distance the suspected crash site is away from anything.

2000 Km is a very long way...and its not 2000Km away from London or New York its 2000Km away from Perth...as far as the rest of the world is concerned that is 2000Km away from nowhere.

There are not many wireless electronic systems that are reliable or at all effective over that distance without a satelite.

The middle of the indian ocean might as well be a black hole......its so far from any where it would be of very little military interest to any body...as for crawing..with anything but fish.....I don't think so.

The area is just vast.

You could put all the ships of all the Navies in the world out there and have enough room that they could all be out of visual range of any other ship.

Vast serioulsy vast.

cheers

Dennis Isn't that how they now believe they know what direction the plane took. I though that I heard something released by Inmarsat that they finally worked out which direction it took.

It appears that the on-board mobile phone system had a "keep alive" network connection to it's satellite network, and it allowed the boffins at Inmarsat to eventually get an idea where the plane could have gone.

I wonder if they could trace us. We use Inmarsat. Hmmm. Can't bloody well get away can we!!! Big Brother is watching.

Phil

Bob,

We have GPS Auto Steering Control on two of our Row Crop tractors which records all movements including speed, direction etc. Even does a loud warning every 15 min. "Driver Alive Alert" where you have to tap the screen or the tractor will stop.

http://www.spidertracks.com/

Designed for tracking aircraft, cheap as. Designed after it took 2 weeks to find a smashed helicopter. The aircraft industry is still using technology of the 60's in the main for comm's and location, not making use of the satellite technology of today.

http://english.martinvarsavsky.net/general/aviation-is-stuck-in-the-60s-a-reflection-on-mh-370.html

All aircraft on the Australian register are required to have EPIRBs fitted that operate on an inertia basis, that is on impact...

But when a large plane hits the water at a couple of hundred miles an hour.
Not much is going to be in one piece.

cheers

Usually only a blackbox and an epirb!

My experience with those sorts of devices doesn't actually relate to the physical characteristics but rather the internal electronic design.

Still , when I was once reviewing the design of a saftey device at petrol stations , I always remember the comment about wether to implement a better sort of oscillator and comment went - well its not as though its likely to ever actually be used !

As The Landy said, aircraft Crash Position Indicators (CPI) are operated by an inertia or G switch. They also have provision to be switched on by a switch on the CPI or a switch in the cockpit. They transmit a code which relates to the aircraft tail number and position.

"The biggest problem is what the transponder will transmit too and how much power is required to do this.....the plane in question is suspected to have gone down what..2000Km away from the nearest contenent...that is Australia..that is a long way from anywhere."

There has been considerable mention here and elsewhere of the aircraft's transponder. It is not really relevant because it relies on a query from ATC radar (max range about 320km - see Followup 811969 further up the page) before it replies with limited information (which does NOT include position) to ATC.

The really useful piece of kit is ACARS. This broadcasts, amongst a heap of other things, the aircraft's position, via satellite to whoever wants to receive it. Range from land-based stations is not an issue. For a demonstration, install an app called Flight Radar 24 on your iOS or Android device. (Get it from the Appstore or Google's Playstore. It is free.) It will appear that your phone or tablet has turned into a world-wide radar system. The info required to make this happen comes from ACARS.

The missing aircraft had this equipment and was using it, but along with other communications equipment, it was switched off or deactivated early in the flight for reasons as yet unknown. Had it not been deactivated we would know precisely where the aircraft went down.

I would not be surprised if one of the results of this accident is the compulsory use by commercial aircraft of a tracking device like ACARS that is somehow powered separately from everything else and cannot be switched off while the aircraft is in flight.

This raises issues of the sovereignty of nation states. There is an organisation called the International Civil Aviation Organisation. Member states (the majority of nations) of ICAO bind themselves to its recommendations and directives. Some other states like to go their own way.

Cheers

Frank (retired ATC)