When ready to descend

[Kian Milani]

Silly question but if I'm at cruising altitude, I've nearly hit my TOD and Controller says 'Descend to FL130 when ready to descend'. What do I do in this situation? Do I have to tell them when I'm descending or can I just descend. Thank you.

[Sean Harrison]

Depends which country you are talking about.

[Kian Milani]

Sean Harrison, I am talking about Australia

 

[Sean Harrison]

For Australia. Ok, it’s been a while but I believe the proper report from ATCO would be “..when ready, Descend FL130…”

If you are ready then you are now clear to descend to FL130,  if your not ready and there is a ti e delay, it is best to report when you are vacating your current FL!

e.g. “..Descending FL130!”

[Andreas Fuchs]

I think that is a judgement call. When you are on a very busy frequency and you get such a clearance, do not report that you have commenced your descent, don't clutter the control frequency with irrelevant information. When it is quiet and you personally feel better by reporting your descent, then do it, but unless ATC asked you to do so, don't. It's like intercepting a final approach track: unless ATC asks you to report it, don't. They have radar, they can see you. If they don't, they will ask you to report it. In some countries you may have to report it, but ATC usually let's you know, e.g. in Switzerland.

In the real world I do not report descent in such circumstances, because ATC has a) instructed us to do something and b) we read the instruction back: ATC knows that we are going to descend at some point and he would only instructed us to do it, because the airspace is clear for this maneuver. Case closed.

The phraseology usually is:

• when ready descend flight level/altitude xxxxx (QNH/altimeter)
• when ready descend flight level/altitude xxxxx (QNH/altimeter), cross ABCDE at level OR reach level yy miles before ABCDE
• pilot's discretion descend flight level/altitude xxxxx (QNH/altimeter)
• pilot's discretion descend flight level/altitude xxxxx (QNH/altimeter), cross ABCDE at level OR reach level yy miles before ABCDE

[Trevor Hannant]

To add to Andreas' points above, experienced controllers will have a fair idea of where your TOD point is so will be expecting to see you start descending around there.  If you don't and it looks a little late, they may come back and ask you to report descending or ask you to confirm you are aware you can...

On a slight tangent, recently I've had a number of pilots simply descend as soon as I give this instruction, resulting in them being level anything up to 50 miles before they need to be!  So for those unsure on what this means, in simple terms - if you're given a "when ready" descent, stay at your current level until the TOD point in your FMC/plan THEN descend to the level given by the controller (and no further!)

[Sean Harrison]

In Australia, he said!

[Andreas Fuchs]

Sure, but when you have received clearance to descend and you made your readback, that report is done with the readback. That would be my cheeky interpretation. Don't forget, pilots are lazy 😄

Edited February 7, 2023 at 09:24 AM by Andreas Fuchs
Better wording

[Kian Milani]

Thanks everyone!

[Dustin Rider]

23 hours ago, Andreas Fuchs said:

Sure, but when you have received clearance to descend and you made your readback, that report is done with the readback. That would be my cheeky interpretation. Don't forget, pilots are lazy 😄

There is no denying that last statement, speaking on behalf of myself. While the AIM also requires vacating altitudes, which is accomplished when you readback a descend and maintain clearance. For pilot's discretion descents, though, since you're not required to vacate the altitude the initial readback doesn't always meet the requirement.

That said, even though the AIM requires it in the States, it's a rare day that I ever hear a pilot report vacating an altitude on a pilot's discretion descent. Even when I do it, which isn't all the time due, as you put it earlier, to determining that such a report would be more hindrance than help on a busy frequency, at least half of the controllers sound surprised at the report.

Back when I worked at ZDV, I always appreciated the report because it did two things: made me look at the datablock to see if I needed to do anything else with it (handoff, pointout, etc.) and gave me one more chance to make absolutely certain there was no traffic for that aircraft, just in case I missed anything when I initially gave the PD descent.