The most likely loss of comms is not a hardware failure but a loss of contact with the current unit because you flew out of their range at ~150kt. Perhaps preceeded by having been given the wrong frequency and taking a while to discover that. It is quite possible if you are flying at a low level, and more so along a coast with mountains on it.
I don’t think this is true anymore but when I last did a lot of VFR in France (2005) I sometimes – at weekends – found a large area FIS region frequency totally dead.
This doesn’t just happen low level VFR. A couple of months ago I was flying IFR at FL100 from Cordoba to Mallorca. Sevilla approach wanted to hand me on to Valencia. No response from Valencia, Sevilla eventually gave me four frequencies to try Valencia on. By the time the fourth one got no response I couldn’t raise Sevilla either. (Probably just wanted rid of me by then.) I flew for about 30 minutes before getting a response from Valencia. Fortunately I was on the FP route, so just continued. Nonetheless, I found it a bit disturbing, as it hadn’t happened before.
I flew for about 30 minutes before getting a response from Valencia. Fortunately I was on the FP route, so just continued. Nonetheless, I found it a bit disturbing, as it hadn’t happened before.
I would be very worried, if such a thing happens while one is flying in IMC.
Wouldn’t that be almost a reason to squawk 7600 for radio failure? One will probably try some other stations and, as the equipment aboard is not broken, reach someone… But it is a weird situation.
A few years ago I went to a presentation by NATS (the main UK ATC place) at Swanwick, where we were told that if you squawk 7600 “you will probably be shot down”. I asked the guy (a senior official) to repeat it and he did.
I do mean 7600, not 7500 which is obviously much more dangerous.
I am sure the rules of engagement aren’t quite that stupid (because a temporary loss of contact is so common in the airline world… 500kt speeds) but it does seem to me from that and other stuff that 7600 is probably one of the last things you want to do, especially in IMC where a visual ID on interception is impossible, so some crazy person might do something stupid.
I would continue with the filed route and try to call up some FIS unit for that bit of the VFR chart and then work from there. If you don’t have a VFR chart, try 121.50.
No response from Valencia, Sevilla eventually gave me four frequencies to try Valencia on. By the time the fourth one got no response I couldn’t raise Sevilla either. (Probably just wanted rid of me by then.)
Was that in the ‘Yeste corridor’? If so, then pretty standard. There is an area where at FL100 or so you cannot communicate with either Valencia or Seville. Mostly the controllers alert you to that, but not always.
Wouldn’t that be almost a reason to squawk 7600 for radio failure?
Well, it would certainly attract attention. But, as Peter said, not necessarily in a pleasant way 
And, at that stage, I had no reason to think that I had any problem with my radios.
Was that in the ‘Yeste corridor’?
Yes, it was. Valencia didn’t respond on any frequency (I continually cycled through them for the period) until I reached ASTRO, which is about 45nm from Valencia.
In fact, these are all no cases of radio “failure”, but rather loss of communication.
So I stand by my statement that a dual radio failure (unless the entire electrical system failed) is a very improbable event.
Yes, it was. Valencia didn’t respond on any frequency (I continually cycled through them for the period) until I reached ASTRO, which is about 45nm from Valencia.
Ah well, standard event for the area then. Surprised ATC didn’t mention it to you. I’ve flown that route quite a bit, and 10k simply isn’t high enough there. If you really need to speak with someone, then try a relay through an airliner (plenty around on that route) on 121.5 or one of the high-alt frequencies if you have them.
Ah well, standard event for the area then. Surprised ATC didn’t mention it to you. I’ve flown that route quite a bit, and 10k simply isn’t high enough there.
Thanks for that. What’s the minimum alt for continuous radio coverage around there? I liked Cordoba and will be going back.
Thanks for that. What’s the minimum alt for continuous radio coverage around there? I liked Cordoba and will be going back.
Not 100% sure. I’ve been up to about 15k in that area and IIRC even on that flight the Valencia controller said she’d probably lose me soon and try to contact Seville in about 20-30 miles. Normally fly a/c w/o O2, so in the 8-10k region. There it’s exactly what you experienced. Does depend a bit on the wx, but by and large there is a stretch of about 20-30 mins (at around 120 – 140kts) where nobody hears you. If you are nervous about this ‘hole’, suggest you obtain the high alt frequencies for the area so you can talk to CAT above you for a relay.
I once tried to contact Albacete, didn’t get a reply. Guess they were closed / off duty (it’s one of these mil fields with limited civ ops hours). There are a few areas around southern Spain where due to terrain you are in and out of radio contact quite a lot. The most annoying is the western VFR approach to Malaga, where LEMG can only hear you once you are almost over the field. One gets used to it….
Other than that, second Cordoba. Nice place and some great restaurants (and of course some amazing architecture)!
If you are nervous about this ‘hole’ …
Now that I know it’s normal, and the controllers are aware of it, I’ll be a bit more relaxed about it
