# Where have the planes gone?



## KeithChesterfield (Mar 12, 2010)

In my time between walking the dog and the 'bar' opening I've been watching at least 8 planes flying over South Korea on www.planefinder.net.

They are all on the same flightpath and as they approach North Korean airspace they disappear one by one off the screen.

I presume they haven't all crashed or been shot down so why would they go off the radar?

Don't waste too many brain cells or time worrying about it - but it does seem peculiar for them to vanish.

Sic Luceat Lux Vestra - as we used to say.


----------



## Spacerunner (Mar 18, 2006)

Has no one told you about N. Korea?


----------



## rod_vw (May 10, 2005)

My understanding of how these aircraft tracking sites get their data is from ground radar type tracking stations. It's reasonable to assume that North Korea doesn't want the rest of the world to be able to monitor flights so doesn't broadcast such data.

Rod


----------



## rosalan (Aug 24, 2009)

You can, or so I believe, only see the aircraft when their transponders are switched on, whatever they are. Have a look at Africa, almost no aircraft have them on. Perhaps for security or that nobody is looking for them.

Alan


----------



## Stanner (Aug 17, 2006)

It's not the transponders it's the receivers on the ground - if there are no receivers there is no detection and no location of the plane.

If you watch a low flying plane such as the flying school planes that operate out of Oxford they sometimes vanish "off the radar" occasionally because they have broken contact with the ground stations receiving the transponder signals. The higher a plane flys the easier it is to keep in contact.

So the loss of contact over N. Korea could be A- No ground stations or B- The planes transponder has been turned off for some reason to do with being over N.Korea.

Planefinder are always asking for more ground detectors in areas of poor coverage so if you know anybody in N. Korea why not ask them to sign up.
http://planefinder.net/about/coverage/

Now another question for you............

I live under the usual flightpath for planes eastbound from BHX. I can go the whole evening without hearing any of them all flying on roughly the same path and at roughly the same height BUT I nearly always hear the Emirates 777 BHX-DXB flight EK38 why? 
Do Emirates have noisier engines than anyone else? Other airlines use 777s on that flightpath, but none are so regularly noticeable as the Emirates planes.


----------



## Landyman (Apr 3, 2010)

As I understand the system it is mostly based on enthusiastic aircraft spotters who have Mode-S receivers, a small radio connected to an antenna, hooked up to their computers.

Most large aircraft have a Mode-S transponder that transmits an ID code. The code is a jumble of data that is converted into the aircraft type, speed, heading etc.etc. by the computer software. That data is shared over the internet with Planefinder, FlightRadar etc.
As they share their data they usually get free subscription to the apps.

Small 'puddle jumpers' usually aren't equipped with Mode-S and military aircraft, if it is fitted, usually don't transmit.

If you were unfortunate enough to live in North Korea I very much doubt that you would be allowed to have anything like a receiver let alone send the information out to the wider world.

Richard.


----------

