Good practice for using both radios / going off frequency
 

Hi, say in the case of having a LARS/radar service but about to overfly or come close to airfield zone (but not enter it) and wanting to give a heads up to that zone (e.g. just to advise on overfly ETA and altitude) without leaving the LARS service (because it's still wanted after passing the zone), what is a good practice? Two options I can see, (1) request the service for a temporary off frequency to speak to the zone, (2) utilise second radio to do it (making sure to navigate the tx/rx audio panel switches). Can some more experienced pilots advise? I'm a relatively new PPL(A) on PA28,

option 1 is better, just tell the lars youre going off freq for a minute, tell the zone you are working xxxx lars, and are making a courtesy call to advise them of your transit, especially if they have instrument procedures outside of the zone, ie holding traffic may be above 2000ft, and then tell the lars youre back on freq.
option 2 if you have two pilots, one flying using box one, your mate can use box 2 for the courtesy call.

Good questions.

I think that telling the LARS controller you want to have a quick chat with the airfield is a great idea, as that controller might already have coordinated your track with the airfield, and save you the bother. In which case, your call on box2 would be a needless interruption to the zone controller.

What's not at all acceptable is when you have only one radio and you just go off freq to talk to someone else. When you have engaged (contracted) with the LARS controller, even for a Basic Service, you should let them know before changing.

Regardless, using Box 2 is a great idea when you have it, as you can still (try to) follow what's going on around you on the LARS freq.

There are differences of course, if the airfield is Linton or if it's Shobdon.

LARS can co-ordinate the crossing clearance of an ATZ if it has ATC; if it's AFIS or A/G the pilot should give them a call.
Even Heathrow allow you to go off frequency when crossing over Fairoaks/Waltham/Denham.

Yesterday I asked Leuchars if I could leave the frequency to pass a message to Dundee. The controller passed the message for me.

That seems to me, to be a much safer way to operate.

The snag with operating two boxes at once comes when there are simultaneous transmissions and you're not sure which one was for you, or even if either were - doing more harm than good. Most RADAR units will gladly let you call another agency and keep the assigned squawk but one unit I know say 'Squawk 7000, change en-route good day' then expect you to go through the whole diatribe of a new call to them 30 seconds later. That's still better than leaving the LARS frequency without telling them - a complete no-no.
We've one new 8.33 COM/NAV box and a second 25kHz box. We now only use the 2nd box for listening to ATIS etc. The new box has all the local frequencies programmed and is easy to flip between them. It also saves a lot of mucking about with our overly-complicated COM panel.

One tip - try and stay one step ahead of the next agency you need to contact sep up on the 'standby' side. You might not always be right, but be prepared. Also, write down every frequency you're given and read it back (along with pressure settings and squawk codes)

TOO