Originally Posted by
alexbrett
I heard a claim it's because setting up a new hold (eg at one of the RNAV IAFs) would require an ACP (airspace change proposal) to be done, but not sure on the truth of that.
Your source was correct: CAP725 - Introduction - para 6iv is the reference. Whereas many of the triggers for an ACP contain the caveat "within controlled airspace", the one referring to holding patterns does not. Therefore, by clear inference, changes (as described in the CAP) to holding patterns in Class G airspace are subject to an ACP. Consequently, airports try to retain their existing holding patterns, based on terrestrial navaids, to minimise expense and avoid stirring up the NIMBYs.
https://publicapps.caa.co.uk/docs/33...16%20amend.pdf