Radio Problem with London Information
 

Has anyone else had problems communicating with London Information on 124.6000 when out over the North Sea? On a group trip to Ostend on Wednesday at least 3 aircraft lost contact with London Information when more than about 15 miles off the Kent coast. In each case we were able to hear them clearly but they were unable to hear our replies when they called us or we called them. In my case I made a blind call to London and then made contact with Ostend when crossing the FIR boundary. Ostend said they would let London know we were in touch with them. On the return trip, when I tried to contact London at the FIR boundary, I could get no reply although I could again hear them clearly. I called Southend and made two way contact although they said they could give me no service until I reached the coast. Bit worrying when 25-30 miles from the coast (at 4000-5000 feet) and you can't talk to London. Since the problem affected at least 3 aircraft it was clearly not a problem with our radios - unless the fact that we'd all got 8.33kHz radios and there is some incompatibility with London's system...

There was a notam for London Info availability on certain frequencies for that day but I don't recall the details.

In fact it's still open till 11th. 124.600 not available plus two others. Use H24 freqs

NOTAM B1611/17

Flight was not during those late hours. Contact outbound was initially made on 124.6 and then lost. London continued to call us on124.6. Notammed unavailability is not the explanation.

What route were you flying out from Kent?

If they were going offline for a bit that day it seems likely that they might have been using backups/temporary antennas or something else that reduced London's transceiver(s)'s efficiency.
Anyway there are often holes in London Info's coverage offshore, I should not worry about it.

Aircraft known to be affected were in the area of DVR KONAN VABIK Manston. If London Info knew they were using temporary antennae, I'm surprised they just kept calling on 124.6 and did not suggest re-contacting on a different frequency. I worry if I'm seen to disappear on an ATC frequency because I've seen many reports of the efforts the controllers then have to go to in order to ensure the safety of their non-responding contact. The fact I was squawking mode S might have reduced their concern though.

I was under the impression that London FIS was a non radar service?

I quizzed them about that when they gave me a code some years ago and later provided a traffic avoidance suggestion. They said they sat about 10 feet away from a radar screen and would look at it if it seemed like a good idea.

I believe they have a radar screen for situational awareness but are not allowed to use it.I used them that day whilst outbound on 124.6 as far as the boundary but on the way back from Ostend was totally unable to raise them at 2500 feet. They were very busy and possibly bandboxing as I could hear aircraft talking to then as far away as Enniskillen and St Athan.I like to use them but it never worries me if I can,t raise them.Much better service from the units on the other side of the channel.Regards Stampe.

London Info is operated by licenced Area FISOs and in the UK, the privileges of the licence do not permit the provision of radar service. I occasionally used to phone them when I was operating Farnborough LARS to warn them one of their squawks was (for instance) about to infringe CAS, so maybe that's how andrewgr2 got his traffic info. On the other hand they can provide a 'proximity hazard warning' if two aircraft advise they are in positions close to each other.

Not even an alerting service???

As the notamed closures of London FIS affect all 3 frequencies, I think it unlikely to be any kind of technical issue. It's probably (like most ATC notamed closures these days) down to staffing.

If you are concerned by FIS coverage then you should MOR it.

Over East Kent we have usually had to climb rather high to get establish comms with London Info and it's always seemed a bit flakey.

When I requested a basic service Southend said something like - "you are outside our service area. Call us again when crossing the coast. "

So far as technical issues are concerned, it still seems strange to me that I could hear their calls to me clearly, as well as other aircraft on the other side of England but they could not hear my replies. Are their transmitters and receivers not co-located?

Try 123.225. They may say you're outside their area (things have changed since I retired) but at least you'll be talking to a radar unit so if you need to use the 'M' word they'll be able to identify you quickly. Radar coverage over east Kent is excellent using either Pease Pottage 23cm or Heathrow 10cm radars (much to my surprise I could 'see' at helicopter between Herne Bay and Reculver at 800ft when they first piped the 'new' 10cm into Farnborough) and RTF coverage is excellent too; I had no problem talking to traffic at low level (300ft ish) over Pevensey Bay.

I presume their transmitters and receivers are co-located. I would think that their transmitters are a lot more powerful than an aircraft's radio. Which might explain why you can hear them, but they can't hear you.

As for hearing aircraft on the other side of the country.....this is because when London info are operating with one controller on all three frequencies, their system re-transmits calls on the other frequencies.....ie if someone calls on 124.75, this call gets transmitted by their transmitters on 124.6 so everyone there knows not to step on the transmission. ....and vice versa, so that is why you can hear aircraft hundreds of miles away.

Your radio must be ok if you got comms with Southend over the sea.

Hmm. One might have felt tempted to reply along the lines of "I can't establish contact with London Information, so can I remain with you for an alerting service only until I reach the coast?".

No temptation at all....perfectly normal. I did it all the time with
Lydd and Manston.

Thanks, Chevron. Noted for the next cross-Channel trip.