"Descend at your Discretion"??

[Mig29]

flew once toward YUL from the north of Quebec, and the controller told me (I was VFR) to descend to xxxx feet at my discretion.

I was quite a way from the destination and not that high (single piston a/c) so I wanted to go little further. After not even a minute, controller came back to me and then said 'descend to xxxx feet', after which I did.

Now, is there are time period that best defines the word 'at my discretion'???

Thank you guys!

[Dog]

No, it means just like it sounds. However I like to let them know if I'm planning to maitain alttitude a little longer, just to be polite. I think you just got a cranky one or he really meant to sa "Maintain #####"

[bater]

Maybe he meant if it is safe to do so.. seeing as how you were VFR.

[ski_bum]

This happens in Winnipeg all the time too, "at your discretion " means exactly that. However as Dog said, its polite and good airmanship to say that your gonna stay at XXXX feet for another 10 miles or so, or give a reason why you want to stay high, ie. turbulence and they will know what your thinking. I have had the "descend to XXXX feet at your discretion" as far as 35nm back from the airport.

[Hotel Tango]

Just like everyone else said, I believe that you did nothing wrong... as for the controller it may very well be that there was no conflict at the time he made the first call but had to get back to you due to a traffic conflict that arose which necessitated you to now descend and hold that newly assigned altitude.

Just a guess. The controller may have just been looking out for you.

[polythene_pam]

pilot's discression, in the Canadian ifr world at least, means that you can start your descent whenever you want, but once you start down, you are expected to maintain a normal descent rate.

In the states, you're allowed to level off on your way down, but not in Canada.

VFR in class E or G airspace, altitude is always at your discresion, meaning atc can't tell you what to do, only suggest.

In your situation, you were obviously under positive control, so you were right to maintain your altitude till you see fit to descend. You could say "planning descent in 10 miles/5 minutes" or whatever, but there's no real need to. If the controller said "at your discression", he obviously expected that you may not want down right away. if not too busy on the rt, it's nice to get a little "leaving 9500 now for 5500" when you finally begin your descent.

Don't feel belittled by the fact that he came back and pushed you down so quickly. It's just standard procedure. Maybe his plan changed and he decided he actually has to get you down sooner. You did nothing wrong. I'd even say it's bad controlling to give a discressionary descent and then push you down less than a minute later. Just bad planning on his part.

Possibly, he says "at your discression" to every plane to come over, and just spat it out, when really he intended to get you going down.

Often, every aircraft coming into a sector will get an automatic discressionary descent. Then when one of the aircrafte decides to start down, you have to go to the others and push them down too. If it happens 10 seconds after you got your discretionary descent, then so be it.

[fougapilot]

Mig,

Don't worry about it, it happens all the time. ATC gives you this descent because they expect you will start a descent at a certain point. when you pass that point and are still maintaining your altitude, some of them may get cranky. Such is life

D

[Dog]

It might be useful to point out that controllers expect a "standard rate of descent" of 500 ft/min for a non-pressurized a/c. If you fly beyond the top of that profile (requiring a higher rate of descent) you might catch him off gaurd.

[polythene_pam]

when you pass that point and are still maintaining your altitude, some of them may get cranky.

Not true. If a controller gives a discressionary descent, they don't care where you start your descent.

If they need you to start down, they'll tell you to start down.. Doesn't mean they're being cranky!! Some controllers just sound cranky when they're doing their job.

Giving a discresionary descent is basically doing you a favour. He could have just waited til he wanted you down, and then given you the descent with no descresion. He could have pushed you down right away instead of giving you the discresion. He's trying to restrict you as little as possible.

There's no WAY a controller would get cranky at a pilot who wants to hang it up for a while after being given a discresionary.

On the other hand, if he gave you a descent without Pilot's discresion, and you waited, or tootled down at 100fpm, He could get very cranky. Like was said before, he may have thought he didn't give you P.D. Either way, not your fault.

[Mig29]

no I didn't take it personally, as a matter of fact ATC guy was quite nice, just something that happened first time, so I figure I'll ask you guys if you were in the same boat

thanks guys

[gr8gazu]

All good points Polythene, I would just like to add a note that in many, no most countries outside of Canada and the US, a clearance to descend "at pilots discretion" shifts the responsibilty of terrain clearance to the pilot. This is very impotant to keep in mind!!

[fougapilot]

Poly,

Perhaps my words were chosen poorly.

the fact is, most Jets will descend on Vnav with a preprogram 3deg descent angle. ATC is aware of this "standard" procedure and tries thier best to facilitate our operation by giving us a PD down to xxx alt.

More often then non, if we select a steeper angle in our FMS and "bust" the point where ATC expected us to go down, they will come back and insist you initiate a descent. Nothing wrong with it, just the way it is.

bottom line, anytime you plan something that differs from the "norm" let ATC know.

D