Question to ATCO´s

[A-3TWENTY]

During final vectors a controller tells you to descend to 4000FT and clears you to an ILS that starts at 3000Ft.

May I descend to 3000FT or I have to intercept it at 4000?

Thanks All...

[Chilli Monster]

1) There may be traffic below you at 3000ft which is why you're being kept high.

2) What makes you think the ILS starts at 3000ft? It might say that if the approach is being flown procedurally, but you've already stated you're being vectored. Provided you're put on the localiser at a distance that will allow glideslope capture from below you can start it from any altitude with the DOC of the equipment.

So - maintain 4000 ft until glideslope intercept in your particular example.

[eyeinthesky]

I think this question shows quite clearly why we have to do what's discussed in this thread!

http://www.pprune.org/forums/showthr...ight=localiser

[Little One]

Here in SA when We say Clear Approach It means one has unrestricted decent so in a case like at JNB Initial approach altitude is 8000ft. Initial instuction is say decend to FL120 Once you are now clear of traffic below and nothing else should affect The clearance will be Cleared ILS aproach. This now meands that one can decend to the initial approach Altitude and then further on the Glideslope.

If we want trafffic to maintain a specific altitude above the initial approach alt for traffic etc we will say cleared approach leave 9000ft on the glideslope. (or a Specific DME)

Most Foreign crews do not decend when cleared for the approach here so it has become standard for us to say decend 8000ft cleared approach but only to the foriegn crew all locals just get Cleared approach but according to our ATCI that is all that is required (decent is now applicabe according to the relevant chart)

[Spitoon]

Th UK gets a lot af bad press for doing things slightly differently sometimes, particularly when it comes to clearing aircraft for an ILS, but as eye points out it helps to overcome misunderstandings about the level the aircraft should fly at. As someone who has been caught out by an aircraft descending when I didn't expect it to, I'm a great supporter of the UK phraseology.

I think it's important to point out that I don't think anyone is at fault - controller or pilot - when there is a misunderstanding about the level to which an aircraft can descend in the circumstances that A-3 describes. It's actually the result of imprecise phraseology set by ICAO.

I'll now duck 'cos I know it's an emotive topic!

[Scott Voigt]

If you don't like ICAO phraseology just use ours <BEG>... It works just fine for getting them on the ILS...

<grining, ducking and running like hell...)

regards

Scott