I wondered if British area controllers listen to / have a switch to emit on 121.5 MHz or whether that is “reserved” for the actual search & rescue guys (I believe that is the Royal Air Force Distress and Diversion units) in the UK, or if they somehow have other restrictions (low power emitters?) on their capacity to use the guard channel? I “often” hear Langen Radar call up airliners that they’ve lost contact with on 121.5, and occasionally I also hear French ATC do that. But yesterday, I left the coverage area of one of London Control’s frequencies, and they resorted to relaying the request to switch to the new frequency to me via a Speedbird (British Airways) plane. Anybody know why they had to go such an indirect route?
UK ATC for Class A and Class D don’t listen or talk on 121.5, this is delegated to RAF(U) D&D who handle it, D&D sits within NATS Swanwick so coordination is easy
I did call 121.5 on ground at Southend by mistake, I think some airliner with Spanish accent called back to tell me I am on the wrong frequency just as I was about to switch to Ground frequency
RAF cover for 121.5 is down to 1000ft agl with VHF-style direction finding
No idea if ATC can transmit but I imagine for airliners on lost com they would get RAF to do it?
“RAF cover for 121.5 is down to 1000ft agl with VHF-style direction finding.”
I think only in the South. I’ve seen a cover map somewhere.
But yesterday, I left the coverage area of one of London Control’s frequencies, and they resorted to relaying the request to switch to the new frequency to me via a Speedbird (British Airways) plane. Anybody know why they had to go such an indirect route?
Because the Speedbird was close and ATC found it will be the easiest and best solution that way.
I think only in the South. I’ve seen a cover map somewhere.
Maybe, also I heard they are cutting back on some nationwide VHF transmitters & receivers, so they can’t triangulate easily…
It’s not very clear; the blue line is the coast with the red circle over London. The original is on this pdf from the CAA, and a bit more info from the RAF at Swanwick. Scotland, Northern Ireland and Cornwall are obviously expendable
Edited to add: the second pdf has a list of direction finding stations, but it’s from 2017 so may not be current
Thanks for the reference my guess that refers to AMSL not AGL? and it is for VHF triangulation not raw radio TX/RX coverage?
My understanding anyone flying bellow 3000ft amsl OCAS without ModeS/C is not worth saving, they already sold their lives to the devils
I don’t think there is any connection between
I can’t see a tech reason why LTCC cannot listen on 121.5. Presumably it is just a policy; nobody with the time to respond.
The above mentioned 2000ft/3000ft coverage is just D&D, which nowadays gets very little use.