That is my guess too, but what is your reference for the statement?

Max Reheat - you are not entirely correct.....

From the ATSIN :

4.2 Exceptions. Where a controller deems it necessary, for traffic separation purposes, to ensure that an aircraft joining the ILS does not commence descent until specifically cleared by the controller, the following alternative form of phraseology may be used:
a. ATC Instruction:
(Callsign and vectoring instructions as at present)
followed by
“……..report established on localiser, maintain (level )”

Have to use it where Intercept is beyond protected range of Glidepath, which for our traffic depending on runway can be 75% or more of the inbounds.

DD

Today at LGW produced
"Left heading 290, report established on the loc. When established descend with the glide path" (or similar!) which seems to cover most eventualities, if somehwat long-winded.

I might be wrong, since i am just a trainee, but i thought that "cleared for ils rwy XX" meant the acft was cleared to intercept and follow the localizer, then the glide path and descend until the landing (when cleared from twr) or MAP, as stated in the proper chart. Do you mean it is necessary another clearance to descend when established?. It makes no sense to me.

@belk 78,
you are right but here we have another problem.
Some CAA , ANSPs have different rules, for some reasons and that is the difference. They have paper where is written that you have to clear a/c to LOC only, then another transmision for GP descent.
If someone is first and better it doesn't mean that he is always right!

In the US it is pretty straight forward you either clear the aicraft for the approach with the vector, or clear the aircraft to intercept the locilizer and maintain an altitude. We use both depending on circumstances. We do not expect a pilot to report established unless asked to report established during the clearance. A lot of foriegn airline pilots report all the time and we just say roger.

"[aircraft] xx miles from [outer marker] fly heading xxx join the runway xx locilizer maintain xxxx until established cleared runway xx ils approach"

"[aircraft] fly heading xxx join the runway xx locilizer maintain xxxx"

An example of when we use the later is the SFO runway 19L ILS, we vector aircraft to join between berks and shake. If we issued the approach clearance with the vector the aircraft could descend to 2900 as soon as they capture the localizer. The OAK 11 ILS is right under the SFO 19L ILS, Aircraft cross ALCAT at or above 2900. In that situation the SFO arrival is restricted above the OAK arrival until the aircraft cross courses or the OAK arrival decends past Plaza.

http://204.108.4.16/d-tpp/0713/00375IL19L.PDF

http://204.108.4.16/d-tpp/0713/00294I11.PDF

Even more, ICAO's "cleared for ... approach" also clears the a/c to execute go-around, which is part of the approach procedure. UK phrase does not mention that, maybe CAO should add some extra words to cover it? :}

its another case of ICAO, NATS, FAA all using different terms. I think it needs further looking at.