To: Air Arabia pilots. From: UAE ACC

[pacificgypsy]

Gypsy: If you receive an unexpected descent instruction out of the blue- say, you are 200nm to run at FL370, and get "UAExxx, descend now to FL 330", how is that achieved? What different ways are there to do it, and what is the most common way?

ferris...this type of clearance is very common and there are a number of ways you can handle it. Some aircraft types have specific limitations eg B777 with RR engines require descent to be idle thrust for first 30 seconds. A gentler descent would be to use VS of 500 fpm (unless ATC requires an increased rate) until you reach your VNav profile.

[Sciolistes]

Here you go chaps, plenty of reading and training material including the R/T manual mentioned earlier. It is all good stuff so fill yer boots.

SKYbrary - Solutions:ALLCLEAR

A phraseology database: https://trainingzone.eurocontrol.int...ogy/search.jsp

[ferris]

I ask because there are rare occasions when it's ok for you to drift down, but most times we want to see some action. When it's needed, different guys use different instructions to achieve that end (with varying results).

[omaATC]

DW, not to make your life more difficult too, but I also stand by what i have said earlier. And all my colleagues I have spoken to agrees with me, neither of them have ever heard that an approach clearance cancells any speed restrictions.

If you are on the 340 or 777, you are welcome to use those rules you have quoted when you fly in to Toronto, JFK and Chicago, but on this side of the Atlantic (or Pacific if you travel the long way around) you need to follow the ICAO rules, and I will give you a bullocking every time you dont comply with any clearence given.

And I am sorry, I cannot prove othervise, just like a cannot prove that any climb or decent clearence does not cancel any heading clearence (which it doesn't.) My point is, unless the rules specifically say that an approach clearance cancels any speed restricion, it doesn't.

And as I said before, if you want to slow down, just ask, and we will accomodate. We also do not enjoy you going around, it generates a lot of extra work (and paperwork) for us.

[desertwarrior]

No worries omaATC, if it makes everyone happier I'll ask you next time I need to slow down on the turn. I appreciate the dialogue mate.

DW

[pacificgypsy]

I ask because there are rare occasions when it's ok for you to drift down, but most times we want to see some action. When it's needed, different guys use different instructions to achieve that end (with varying results).

ferris, my point exactly. So if you need us at Desdi at a specific time, include that in the clearance and we'll adjust the speed to comply. If you need a specific rate of descent till through an altitude eg 1500fpm till passing F280 then include that in the clearance. Although the descent (from an aircraft efficiency point of view) may not be optimum, it does allow us to return to a more efficient profile as soon as we've passed the conflicting traffic etc.

[ATCO1962]

The problem is, mensaboy, the relevent documents can be different around the world. desert warrior has pointed to the American definition of "Pilot's discretion" that exists in the FAA docs but nowhere else, as far as I know. I can't believe that they would allow for an aircraft, in controlled airspace, to descend to any level they want, stop at any intermediate level (including a non-standard one) and then resume their descent whenever they want, based on this flimsy phraseology.

It just highlights the need to synchronise RT manuals across the board, regardless of the whining that may emanate from the world ATC superpowers, and ensure everyone follows the agreed-upon standards. Doc 4444 and any others that contain RT standards aren't enough; we need ICAO members to insist that we sing from the same score when it comes to phraseology and not allow filed differences to suit individual countries.

[BlueSkye]

I'm pretty steamed right now, just spent the better part of an hour writing and researching a reply here, just to have it evaporate into cyberspace somewhere unknown.

This happens to me too. You have see the distance of dummy-spit to appreciate it when it happens.

[ferris]

I can't believe that they would allow for an aircraft, in controlled airspace, to descend to any level they want, stop at any intermediate level (including a non-standard one) and then resume their descent whenever they want, based on this flimsy phraseology.

Why not? They have to have a 'clear run' to be given either PD or "When ready". They either have a clear run, or they don't.

As a cure to losing the posts, I suggest; right click- copy- the entire text, before hitting the submit button. (for some reason, our work computers sometimes have issues like this- maybe to do with the firewall software?)

[Chatz]

I have to admit that on my ATC course (quite a few years back now) we were taught that a clearance for final (ie. approach) cancels all speed control instructions.

Having not been out here long, one of the things I've found it most difficult to get used to is the varying amounts of RT. I guess that's what happens when so many nationalities converge on one location, pilots and ATC alike. It would be nice to see both parties attempting to align their RT with ICAO a little more regularly. Sometimes I feel like I need a translator, and that's just for some of the terminology from my fellow native english speaking friends.