Question regarding descending on ILS when localiser established

[rainman43]

I was going into a Spanish airfield where they wanted us to call localiser established, we called however they never cleared us to descent with the ILS, although we were very close to capturing the glide. As a result I never armed the GS capture button, because I was not sure and didnt want to presume. I had a brief discussion with my Captain regarding this point and he thought that the controllers presume you are going to descend once esb on the localiser and glide captured , however I would normally ask as to "presume" can get you into all sorts of trouble.

I have also had it at some UK airports where they DONT say "once established descend with the ILS" they just want you to say Loc estab. Whats the offical line on this?

Cheers!

[BOAC]

What was your initial clearance? Normally outside UK your clearance is either "cleared for the approach 25R" or "cleared for the ILS 18L...." in which case you just do it. The "call established" request could have been for many other reasons but is not routine in my experience.

[Canoehead]

What he said. In my experience, the magic word is "cleared" for the approach. Once you hear that, you follow the approach plate. You descend on the glide or whatever the plate says. ALSO, any previous ATC assigned speed is cancelled. Of course, a busy approach controller will always assign you a speed on the loc.

[av8boy]

Agreed (although I don't know how it's done in Spain...).

I may say "three miles from LIMMA turn left heading 270 maintain 1900 until established on the localizer cleared ILS runway 25L approach. Report established on the localizer," but that means you are cleared for the approach. The call established is not part of the clearance, but rather, informational for me.

Dave D

[Jumbo Driver]

rainman43, I don't believe a clearance to intercept the localiser ever implies a clearance to descend with the glideslope.

I would normally expect to be given glideslope descent clearance at the latest by my actual localiser intercept. If I was asked to "report localiser established" and still not cleared when that report was acknowledged, I would immediately ask for clearance to "descend with the glide path". There is little point in ATC clearing you to intercept the localiser in anticipation of an ILS Approach if you cannot then subsequently descend to follow the vertical profile.

There are of course places (e.g. LAX, profile descent to runways 24 and 25) where a stepped descent profile does happen These LAX descents start at over 14,000- 15.000 feet when you are over 50 miles out on a straight-in approach but such vertical profiles are only really practical when you are a significant distance out from the landing threshold.

More normally, if you are not given clearance to descend by glideslope intercept, you have the prospect of either a non-standard glideslope intercept from above (not usually recommended) or, if you are a fair distance out, a steeper descent to the next platform height, in order to await a further conventional glideslope intercept from beneath. Neither of these generally tend to make for a comfortable approach.

Generally, therefore, you should expect to be either cleared to "intercept the localiser and descend with the glide path" or cleared to "descend with the glide path" when becoming localiser established. Anything less than this and you should prompt ATC for descent clearance, otherwise you may be setting yourself up for a "rushed approach" or in the worst case a go-around.



JD
:)

[Capt H Peacock]

The UK is peculiar in that you only get cleared a bit at a time, and you can only go down the glidepath when O'Grady says.

Everywhere else in the World, cleared for the approach means just that. Additionally in France, if you're given a heading towards the localiser for your assigned runway, you're expected to establish whether cleared or not.

[bookworm]

The UK is peculiar ... Everywhere else in the World, cleared for the approach means just that.

Well we're British old chap and we're proud to be different...

As a result I never armed the GS capture button, because I was not sure and didnt want to presume.

...and it's probably going to take an accident caused by the confusion of a UK flight crew before we realise that there's a real safety cost to being different.

[BOAC]

JD - NB we still have not had the answer to my Q in post#2 as to what the clearance was. As others have said, around the world it is different to the UK and your post really applies to UK approach clearances, and not the rest of Europe. I cannot comment on the USA, but Canada seems to be 'clear for the approach' also, in which case you are free to arm 'G/S' IAW your company's SOPs without further wittering.:)

[Jumbo Driver]

BOAC - agreed, I was looking mainly at UK.

I believe USofA is "clear for the approach" as well. I am happy to say I have no personal experience of España ...


JD
:)

[ComJam]

Happens a lot in Spain, you get a "cleared for the approach Runway xx" or similar and are then asked to report LOC established...so you are cleared for the ILS. It can be a bit ambiguous, especially for those of us from the UK where the RT standardisation is much tighter.

(Pilar, That's not a critism of Spain if you're watching :})

[rainman43]

Thanks for the replies guys. I just wanted an ATC answer to this. Im sure that ATC did NOT say cleared for the approach, all they asked was to report loc established. We were at an altitude where we were very close to capturing the glide as well which made matters slightly worse.