Descent instructions

[Let'sgoflying!]

Last week my copilot and I received this instruction approaching our destination.
We were at I think 180, and we were not on a star.

"N123 descend now to 14000, then descend and maintain 6000."

We looked at each other to see if we heard it right.

I'll make clear now that this was not a typical variable-rate descent instruction. We've heard 'descend now to xxx, then PD to yyy' a thousand times, same for 'best rate to xxx then descend to yyy'

I responded, "Understand you want us to descend to 6000, N123" in the hope he'd see the possible question his instruction had introduced.

He responded exactly as before
"N123 descend now to 14000, then descend and maintain 6000."
So I repeated his instruction, and we used normal descent rate to 6000 without further interaction.

If anyone has P/CG or AIM clarification on this, I need to learn it.

To make my point obvious, I'd ask - why does he not specify any other altitudes between 180 and 6000? Why not
"N123 descend now to 14000, then 12000, then 10000, then descend and maintain 6000."
The intermediate altitude which was stated changed nothing.

 

[FORANE]

Just a WAG, but the "now" typically would convey an urgency. I would guess he's got conflicting traffic if your descent to 14000 were delayed. Sounds like non-standard phraseology.

 

[Let'sgoflying!]

Could be. Maybe he had a flat affect tone as normal; we did not notice the usual emphasis.
If I were king of the atc world, I would have said 'Descend to 6000, I need you out of 14 in 2 minutes or less'

 

[luvflyin]

Last week my copilot and I received this instruction approaching our destination.
We were at I think 180, and we were not on a star.

"N123 descend now to 14000, then descend and maintain 6000."

We looked at each other to see if we heard it right.

I'll make clear now that this was not a typical variable-rate descent instruction. We've heard 'descend now to xxx, then PD to yyy' a thousand times, same for 'best rate to xxx then descend to yyy'

I responded, "Understand you want us to descend to 6000, N123" in the hope he'd see the possible question his instruction had introduced.

He responded exactly as before
"N123 descend now to 14000, then descend and maintain 6000."
So I repeated his instruction, and we used normal descent rate to 6000 without further interaction.

If anyone has P/CG or AIM clarification on this, I need to learn it.

To make my point obvious, I'd ask - why does he not specify any other altitudes between 180 and 6000? Why not
"N123 descend now to 14000, then 12000, then 10000, then descend and maintain 6000."
The intermediate altitude which was stated changed nothing.

AIM 4-4-10 is where this is covered. There is nothing there that supports what the Controller said with out saying something like expedite descent, best rate, immediately etc. Controllers are warned in the 7110.65, their rule book, that they cannot rely on the 500 to 1500 fpm specified in AIM 4-4-10 d.

4. Controllers need to be aware that the descent rates in the AIM are only suggested and aircraft will not always descend at those rates.

That Controller probably thought by saying now that it would ensure you would. Wouldn't surprise me if he was in training and the instructor didn't have him, or himself, come back to clarify because your last read back had it covered.

 

[BillTIZ]

Descend NOW to 14,000, and then essentially Pilots Discretion to 6,000.

 

[Greg Bockelman]

Descend NOW to 14,000, and then essentially Pilots Discretion to 6,000.

It really isn’t any more complicated than that.

 

[Let'sgoflying!]

The below screenshot is the closest example I can find in the AIM; and in it, atc does say “PD”.

I guess my controller simply left off the PD part, but I had expected to hear it when I restated his clearance with a questioning manner.

It seems I can take some clearances with a more relaxed interpretation, as Bil implies - that’s what the controller essentially meant.
(although unstated, the implied PD in this case means I could have leveled off at 14000 if I’d wanted, right?)

 

[luvflyin]

The below screenshot is the closest example I can find in the AIM; and in it, atc does say “PD”.

I guess my controller simply left off the PD part, but I had expected to hear it when I restated his clearance with a questioning manner.

It seems I can take some clearances with a more relaxed interpretation, as Bil implies - that’s what the controller essentially meant.
(although unstated, the implied PD in this case means I could have leveled off at 14000 if I’d wanted, right?)


View attachment 136336

What page of the AIM is that on? It is not consistent with the Controllers rules. 'To' is the word used in conjunction with the interim altitude, maintain with the final altitude. Yes, you can level off at the interim altitude. It's likely that's what your Controller meant, but starting to do what you think the Controller meant rather than what was said can be a slippery slope.

e. When a portion of a climb/descent may be authorized at the pilot’s discretion, specify the altitude the aircraft must climb/descend to followed by the altitude to maintain at the pilot’s discretion.
PHRASEOLOGY−
CLIMB/DESCEND NOW TO (altitude), THEN CLIMB/DESCEND AT PILOT’S DISCRETION MAINTAIN (altitude).
EXAMPLE−
“United Three Ten, descend now to flight level two eight zero, then descend at pilot’s discretion maintain flight level two four zero.”

 

[Let'sgoflying!]

It's likely that's what your Controller meant, but starting to do what you think the Controller meant rather than what was said can be a slippery slope.

Thank you; that is actually my original concern. And why I replied to atc as noted.

But others seem to think I can accept what I think the controller meant.
That does fly in the face of our normal 'all communications must be precise and without confusion - to avoid a cluster' modus operandi.

At the time I did not cob on to the possibility that he meant PD but I think next time I will specifically ask, "did you mean after 14000, PD to 6?"

 

[Martin Pauly]

I would give the ATC facility a call. There is no place whatsoever for ambiguity in altitude assignments on IFR flights.

If they meant "descend now to x, then pilot's discretion to y", they should have said that. Same for "good rate to x, then ...".

Seriously, file a NASA ASRS report and talk to the facility. This is a safety concern.

- Martin

 

[BillTIZ]

I would give the ATC facility a call. There is no place whatsoever for ambiguity in altitude assignments on IFR flights.

If they meant "descend now to x, then pilot's discretion to y", they should have said that. Same for "good rate to x, then ...".

Seriously, file a NASA ASRS report and talk to the facility. This is a safety concern.

- Martin

I agree, sloppy controller phraseology. And when the pilot questioned or asked for clarification, the controller did not take the hint and use correct phraseology.

I've heard "xxx maintain 6000, give me a good rate through 10,000" or "xxx give me a good rate through 10000, maintain 6000". Both prime examples of improper phraseology.
I've responded "Roger, xxx maintain 6000, Pilot's Discretion after 10,000", just to kick them in the ear.

Yes, I've been on both sides of the mic.

 

[RussR]

Descend NOW to 14,000, and then essentially Pilots Discretion to 6,000.

It really isn’t any more complicated than that.

I can't agree that "inferring" a PD for further descent is a good idea, nor that the instruction was essentially the same thing. It SOUNDS like the same thing, and maybe that was the controller's intent, but that's not how it was said, so I'm not going to assume anything.

The below screenshot is the closest example I can find in the AIM; and in it, atc does say “PD”.

I guess my controller simply left off the PD part, but I had expected to hear it when I restated his clearance with a questioning manner.

It seems I can take some clearances with a more relaxed interpretation, as Bil implies - that’s what the controller essentially meant.
(although unstated, the implied PD in this case means I could have leveled off at 14000 if I’d wanted, right?)

Please do not take clearances with a relaxed interpretation. Ask for clarification, as you did, but when you didn't really receive any actual clarification, ask for more specific clarification as you suggest you would do in a later post, "did you mean PD to 6000?"

It's likely that's what your Controller meant, but starting to do what you think the Controller meant rather than what was said can be a slippery slope.

Absolutely agree 100%. It's like the repeated discussion about being VFR and assigned a heading that takes you into Class B, can you assume a Class B clearance? No, you cannot. And is this situation, I wouldn't assume a PD descent either.

But others seem to think I can accept what I think the controller meant.
That does fly in the face of our normal 'all communications must be precise and without confusion - to avoid a cluster' modus operandi.

At the time I did not cob on to the possibility that he meant PD but I think next time I will specifically ask, "did you mean after 14000, PD to 6?"

Clearly I am one who disagrees with accepting what I think the controller meant in this case. Because if the controller meant a PD after 14000, that does mean that I can hang out at 14000 for as long as I like, not descending any further. Whether that's what was intended by ATC, nobody knows.

I would give the ATC facility a call. There is no place whatsoever for ambiguity in altitude assignments on IFR flights.

If they meant "descend now to x, then pilot's discretion to y", they should have said that. Same for "good rate to x, then ...".

Seriously, file a NASA ASRS report and talk to the facility. This is a safety concern.

- Martin

I agree. Contact the facility and do an ASRS.

 

[RussR]

I agree, sloppy controller phraseology. And when the pilot questioned or asked for clarification, the controller did not take the hint and use correct phraseology.

I've heard "xxx maintain 6000, give me a good rate through 10,000" or "xxx give me a good rate through 10000, maintain 6000". Both prime examples of improper phraseology.
I've responded "Roger, xxx maintain 6000, Pilot's Discretion after 10,000", just to kick them in the ear.

Yes, I've been on both sides of the mic.

I agree that "good rate" and similar terms is improper phraseology. But I don't agree that your clearance and your readback are equivalent. In your readback, you imply that you may hang out at 10,000 for a while (after all, PD allows you to not begin a descent if you don't want to yet). But that isn't what the controller is clearing you to do - they want you to descend to 6000, but not take your time getting through 10000. It may not be a by-the-book radio call, but I don't think it's vague in its intent, unlike the OP's scenario.

 

[MauleSkinner]

I agree that "good rate" and similar terms is improper phraseology.

“Good rate” has always annoyed me. If they need something specific, they should tell me.

 

[flyingcheesehead]

Last week my copilot and I received this instruction approaching our destination.
We were at I think 180, and we were not on a star.

"N123 descend now to 14000, then descend and maintain 6000."

We looked at each other to see if we heard it right.

I'll make clear now that this was not a typical variable-rate descent instruction. We've heard 'descend now to xxx, then PD to yyy' a thousand times, same for 'best rate to xxx then descend to yyy'

I responded, "Understand you want us to descend to 6000, N123" in the hope he'd see the possible question his instruction had introduced.

He responded exactly as before
"N123 descend now to 14000, then descend and maintain 6000."
So I repeated his instruction, and we used normal descent rate to 6000 without further interaction.

If anyone has P/CG or AIM clarification on this, I need to learn it.

To make my point obvious, I'd ask - why does he not specify any other altitudes between 180 and 6000? Why not
"N123 descend now to 14000, then 12000, then 10000, then descend and maintain 6000."
The intermediate altitude which was stated changed nothing.

That... Is unclear, which is not good for altitude assignments.

They could have meant best rate through 14 and then down to 6, or they could have meant descend to 14 now, and PD to 6. Those are not the same thing, and they should have recognized by your query that it wasn't clear and, well, been more clear!

I agree, sloppy controller phraseology. And when the pilot questioned or asked for clarification, the controller did not take the hint and use correct phraseology.

I've heard "xxx maintain 6000, give me a good rate through 10,000" or "xxx give me a good rate through 10000, maintain 6000". Both prime examples of improper phraseology.
I've responded "Roger, xxx maintain 6000, Pilot's Discretion after 10,000", just to kick them in the ear.

I *hate* "good rate through"... What is a good rate? How nervous should I be making the passengers in the back? Generally I'll give you 2,000 FPM unless you're specific. "I need you at 14,000 in three minutes" is WAY better, I know exactly what you need and can dial it up and give it to you without any unnecessary discomfort in the back.

Clearly I am one who disagrees with accepting what I think the controller meant in this case. Because if the controller meant a PD after 14000, that does mean that I can hang out at 14000 for as long as I like, not descending any further. Whether that's what was intended by ATC, nobody knows.

I definitely wouldn't be doing what I think they meant. I'm gonna ask for clarification until I know we're on the same page.

 

[35 AoA]

Phraseology is jacked up. I could see "descend and maintain 6 thousand, expedite through 14 thousand" or something like that. I also wouldn't automatically infer PD from 14 to 6, though maybe that is what he was getting at. Needs to say it that way if that is the case. That is a nonsense clearance IMO, open to far too much interpretation.

 

[luvflyin]

Phraseology is jacked up. I could see "descend and maintain 6 thousand, expedite through 14 thousand" or something like that. I also wouldn't automatically infer PD from 14 to 6, though maybe that is what he was getting at. Needs to say it that way if that is the case. That is a nonsense clearance IMO, open to far too much interpretation.

Ah, interpretation. I’ve been asked that before. What’s your interpretation of this. From fellow Controllers and Supervisors a notch or two up the food chain. My response was, deliberately snarkily, I can’t interpret it, I am not bilingual, English is the universal language of Air Traffic Control.

 

[35 AoA]

Ah, interpretation. I’ve been asked that before. What’s your interpretation of this. From fellow Controllers and Supervisors a notch or two up the food chain. My response was, deliberately snarkily, I can’t interpret it, I am not bilingual, English is the universal language of Air Traffic Control.

Even you guys don't know what you're saying???!!! I KNEW IT!!!!