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Thread: 8.33 exemption extended to end of 2018

  1. #1

    8.33 exemption extended to end of 2018

    This is not unexpected to be honest

    The text in the link reads as:

    ‘UK adoption of 8.33 kHz VCS capable equipment is increasing and feedback shows that over 50% of the UK GA fleet is already equipped, many successfully applying for funding,’ said the authority in a statement issued last week. ‘But the CAA has recently become aware of aircraft equipage issues regarding the limited availability of installers. Hence the Authority has agreed to invoke a number of limited time exemptions to provide flexibility for users and to help with the capacity issues that have been identified. The exemptions will run to 31 December 2018 and are listed in CAP 1606 which may be viewed at the following link.

    ‘Please note that 8.33 kHz compatible radios are backwards compatible, so will retain the capability to communicate with existing 25 kHz ground stations before those ground stations have been converted. Also that existing 25kHz radios can be left installed provided that they are only used for exempted frequencies.’

    In response to a request from Amarjit Singh Bamrah Falcon Flying Services/Bigginair Ltd for confirmation that operators of aircraft transmitting on 25hKz after Dec 2017 will not automatically be prosecuted, CAA GA ANO Project Manager Bob Liddiard made it clear that 25kHz units would remain legal in specific cimcumstances:

    ‘1. If an aircraft is only communicating to ground services on 25 kHz frequencies, then it is permitted that they continue to use a 25 kHz radio until the end of 2018. However, if their flight means that they communicate to any ground service that has transitioned to an 8.33 kHz channel, then they must also be using an 8.33 kHz capable radio. This applies to all aircraft and also overrides part 2 of this list below.

    ‘2. Some specific frequencies have been granted a 12 month exemption to end of 2018 and these are listed in CAP1606. These frequencies cover “sporting frequencies” and the intent is that gliders, balloons, microlights etc. where they mostly communicate air-to-air, can continue on the 25 kHz frequencies. It is felt that within the next 12 months that equipage of 8.33 kHz radios in those areas will have improved.

    ‘During 2018, ground services will be transitioning to 8.33 kHz channels and so part 1 above will have more impact on where an aircraft that has not transitioned can fly. We believe that the timing of their transition will be driven by the renewal date of their annual radio licence which are spread across the year.

    ‘You will no doubt have read about all the other frequency options that we also applied for with EuroControl . These other ones are ground service frequencies and allow the CAA, if requested by the ground service, to grant a temporary exemption to stay on that 25 kHz frequency. It should be noted that we do not expect to have many of these exemptions requested because there is a financial saving in radio licence fee to any ground service that changes to an 8.33 kHz channel. Note that the cost of an 8.33 kHz ground licence is predominantly just one third the cost of the 25 kHz licence…

    ‘It is important that we dispel any incorrect interpretations so that the GA community flies safely and within the law.’

  2. #2
    Diamond geezer 500 Club
    Join Date
    Jul 2007
    Reading that carefully it's clear that it's a very limited exemption. Only if your flight requires you to communicate with ground stations that are themselves still using 25khz and no ground stations using 8.33 can you continue to use your old radio.
    Martin Watson
    Microlights in Norfolk
    Fixed Wing Instruction - Exams and GSTs - Revalidations
    07805 716407

  3. #3
    Quote Originally Posted by Martin Watson View Post
    Reading that carefully it's clear that it's a very limited exemption. Only if your flight requires you to communicate with ground stations that are themselves still using 25khz and no ground stations using 8.33 can you continue to use your old radio.
    How many ground stations do you know that are already using 8.33 frequencies? I can't think of any so far.

  4. #4
    Henry, may I respecfully suggest that that is because you read your NOTAMs in graphic form.

    I am constantly reading NOTAMs that say "XXXX is changing frequency from 129.825 to 129.8250"

    Which means that they have gone over to 8.33 - on the same frequency.

    Laurie (2)
    (that's just an invented example)

  5. #5

    I do understand & this link clears it up a bit better http://www.lightaircraftassociation..../May/radio.pdf
    In summary:
    For good old 25khz channels - what you select on the radio (e.g. 118.625) matches the frequency (118.625MHz). All 25khz channels have a nominal 15khz width.

    For 8.33 the 'channel' that you select on the frequency doesn't necessary match the frequency. For example 118.630 will give a frequency of 118.625MHz but with a 8.33 spacing channel width (7.5khz).

    You may ask why you couldn't simply use 118.625 with a 8.33khz spacing to talk to a 25khz ground station. In most cases this would work - but there are some circumstances where it wouldn't (e.g. where multiple transmitters and offset frequencies are used) and therefore a radio needs to be able to operate in either 25khz spacing or 8.33khz spacing.

    Rather than have two bits of information (a frequency and a spacing) which would have to appear on charts, get passed over the radio, etc .... it was decided to use arbitrary channels that roughly align to the frequency. The pilot doesn't need to know if it is 8.33 spacing or 25khz spacing - he just enters the number given.

    My concern was less the technology - that is what it is - but more how coordinated (or not) the migration to 8.33 channels will be. Whilst I accept the point a chart is always out of date somewhere - if recent experience of the frequency change at Leeds is representative (3 months later AIP and Skydemon still show the old frequency) it has potential to be chaotic.

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