Allocated but unused airfield VHF frequencies ?

[Mooncrest]

Do we still have any of these in the UK ? I don't know but I would be surprised if we did, given the pressure on the VHF airband. I remember East Midlands once had GMC as 121.9 but it wasn't in use in the early 1990s. More recently, Bristol had a GMC frequency but it was seldom used. Leeds Bradford has a Delivery frequency which is manned most of the time (Tower assistant job) but that doesn't stop KLM crews frequently trying to get their clearance from Tower and being patiently redirected.

[Equivocal]

I'd be very surprised if any assignments exist that are never (from when?) used.

If an audit of frequency use was done I imagine most airports would claim that rarely used frequencies are needed for busy periods, backup and in case of other frequencies being blocked.....and are probably used in these circumstances.

[Gonzo]

LHR has a ‘spare’ VHF for use if one of the others gets jammed/too much interference etc.

[Equivocal]

Just curious, Gonzo, but how much is it used? And does Ofcom or the CAA (or whoever looks after such things in the UK these days) ever audit spectrum use/availability that you are aware of?

[chevvron]

LHR has a ‘spare’ VHF for use if one of the others gets jammed/too much interference etc.
At one time all NATS airports had a 'spare' which coud be used for either ADC or APP/APS and yes it was seldom used but 'deemed' necssary in case of main failure or other reasons and likewise there was often a GMC frequency at many NATS and non NATS airports which was seldom used but if it was desgnated as GMC, the DOC was usually very small and it was not supposed to be used for aircraft in the air..

[TCAS FAN]

Is there now any pressure on the UK AMS band now that it is allocated on 8.33 KHZ spaced channels?

[Mooncrest]

Leeds Bradford also has a seldom used secondary Radar frequency in the 125 mhz range. It's needed as a just-in-case back up and was once designated as 'Leeds Director' a few years ago. Very grand! I expect the Delivery frequency would be reallocated to GMC if such a position were ever to open there.

[chevvron]

In addition to frequencies used for ATC/AFIS/AGCS don't forget many others in the VHF airband were allocated for company frequencies plus some were allocaed for MOD trials (I know of 2 allocated to Farnborough which ATC weren't allowed to use) and these latter were ones which were seldom used.

[Buster the Bear]

You require a licence from OFCOM to use a frequency which last 12 months. I assume if you do not renew, the frequency would be re-allocated after a set period of time.