Cleared for the Approach.......

[LadyMatilda]

OK, here is one for all you smart guys 'n gals out there. This is the best way I can demo this, please bear with me.

ATC: Descend 3000'
then
ATC: Turn right XXX cleared for the ILS XX, call est.

If the published glideslope intercept alt is at 2000', does the above clearance allow the pilot to descend to 2000' before GS capture?

[cossack]

No it doesn't.
Or should I say no it shouldn't.
Published Instrument Approach Procedures are published usually with a non-radar environment in mind.
Under radar control, the contoller usually vectors the aircraft onto the localiser at an altitude appropriate to both its distance from touchdown and terrain clearance.
i.e. At 3000 feet you will normally intercept the GP at about 8-10 miles dependent on airfield elevation. As long as you will be on the localiser outside this range no further descent will be given and you will descend with the GP from 3000.
If, however, you want a short final, descent will be given to say 2500 or 2000 feet prior to establishing closer in.
Descent below your last cleared altitude is only permitted either:
a) when localiser established and cleared for the apporoach: or
b) when instructed by ATC.
There has been another thread about RT phraseology with respect to being cleared for the approach before or after establishing on the localiser.
I clear an aircraft for the ILS with the closing heading as long as they are descending to 3000 feet or below, since the protected range of the GP is only 10 miles.
Some people still wait until the "established" report is received. On busy frequecies this can cause the aircraft to follow the Loc at 3000 feet and not, technically, be permitted to descend.
Hope this helps...

[blueball]

If "cleared for the approach", you can descend t0 2,000 (in your example) if you are on a published segment of the approach, otherwise you need to stay at 3,000. Procedure in US was changed after a flight hit the ridge on an approach into Washington Dulles in late 70's or early 80s

[Special VFR]

In the UK we cannot use, when radar vectoring, 'cleared for the ILS' or 'cleared ILS'. It is 'closing the localiser from the [left/right], report established', then 'descend on the ILS'. It is considered that 'cleared ILS' when the aircraft is above the procedural approach altitude is an instruction to descend to that altitude and carry out the procedural approach, if only straight in.

[fweeeeep]

This whole thing was thrashed out about a month ago on this forum. You might want to look back and find the thread.

The sad thing is, that there appears to be different rules for different parts of the world, and that the interpretations can vary widely from one unit to the next.

I do not even want to add my "understanding" to the thread.

I think that if I were a pilot, I would probably verify with ATC what they expected in terms of decent when given such an instrustion or clearance.

[fweeeeep]

In addition to the above, I think that that from a safety perspective, if an aircraft were cleared for the ILS approach from an altitude above the initial approach altitude, a response like:

"ABC123, cleared ILS approach RWYxx, leaving altitude 4000' for altitude 2000'"

would at least let ATC know what you are planning to do and give them chance to stop your decent if that is not what they had in mind for you.