As there are a number of inaccuracies in above phraseology quotes here is the
latest guidance from the CAA - it has changed so many times in the last year it's difficult to keep up
Reasoning for the difference (from AIP/CAP 413):
Due to procedure design and airspace complexity, along with lessons learned from flight safety related incidents and occurrences, the UK has elected to enhance safety by adopting unambiguous phraseology that includes a positive descent instruction to ensure that descent is initiated only when it is safe to do so.
additionally:
Phraseology ‘CLEARED FOR ILS APPROACH’ is used in the UK only for self-positioned approaches. For radar-positioned ILS approaches in the UK, pilots will be instructed: ‘When established on the localiser, descend on the glidepath...’
The actual phraseology to be used
(for a combined localiser/glidepath single stage clearance) is as follows:
"turn right heading (xxx) degrees closing localiser from the right. When established on localiser, descend on glidepath QNH (xxxx)"
Note: glidePATH not slope, not descend ILS etc. No requirement to request "Localiser Established" report but CAA say you can ask for one if you want to.
No doubt it will all change next week....
Instead of all this verbal contortionism why don't they just publish on the approach plates (in very big letters if deemed necessary) "DO NOT COMMENCE DESCENT UNTIL INTERCEPTING ILS GLIDEPATH, THEREAFTER, DO NOT DESCEND BELOW ILS GLIDEPATH." Then we can join the rest of the world in saying "Cleared ILS"
DD