"Descend Pilots Discretion Maintain..."

[Everskyward]

My observation does not agree; I think more than that report. I always did and that's the way the charter company I flew with did.

Your company SOPs can be whatever they choose as long as it's within the bounds of the regs with that would be. That doesn't mean it's required for everyone.

I agree I have not heard people chastised by ATC for not reporting, but what I have heard many more times than once is "Cessna 12345, Minneapolis Center, have you started your descent?"
You can read that a couple of ways, such as, "hint, hint, are you thinking of starting down" of "my scope or your transponder is scratchy today and I don't know for sure how high you are" or "I think you've started your descent at about 200 fpm but want to know for sure before I tell you something different".
In any case, when ATC asks something like that you can imagine the pilot is doing a quick to see why such a question would be asked.

I think it's a "hint, hint" thing. They can see your altitude on radar. If they lose radar contact they tell you. Or if the traffic situation changes they will take away the "discretion" part and just tell you to descend, sometimes within a time limit or a certain FPM.

 

[Geico266]

As McFly notes, AIM 5-3-3a.1.(a) says:
Note the lack of any exception for when altitude reporting equipment is in use. IOW, those controllers were wrong to criticize you for making a report the AIM says you are supposed to make.

That said, a controller who criticizes a pilot for making a recommended report is out of line.

That's what happened to me. I'm on a CC and going near KRFD "C" at night (MAJOR UPS & FEDX sorting facility) thought I would be a nice guy and check in. I reported I was climbing after they said altitude "my discretion". I was "corrected" for reported it. It really took me by surprise. There was inbound cargo heavies coming in, I thought it would be a good thing to let them know, but obviously they could see me on radar.

 

[roncachamp]

You would think so...but it looks like Ron's working at getting his post count up to 30,000 so you can expect this thread to go for a few more pages.

 

[vintage cessna]

Whether a controller is annoyed or not by a pilot stating he is starting a decsent is probably dependent on workload. With a high work load the controller doesn't want any unnecessary BS.

 

[roncachamp]

Only if people keep saying you should ignore what the AIM recommends, or that it's OK for controllers to criticize a pilot on the ATC freq for doing what the AIM recommends.

What's the downside in ignoring this AIM recommendation?

 

[roncachamp]

No, it's a lot more than that. It is the result of a lot of thought by a lot of people including both ATC and highly experienced operations types with backgrounds including light plane instructors, corporate and charter pilots, and commercial air transport pilots. The NTSB and courts generally look on it as the bible on how one is supposed to operate, and deviations from its recommendations are generally considered inappropriate conduct unless you have a really good safety reason for doing it otherwise. So, while it only "suggests" or "recommends", it's more like when your Dad says, "I suggest you get [this] done before bed tonight" than "Hey, here's an idea for you to consider."

If highly experienced controllers had input in to the procedures in the AIM there would not be a significant disparity between what the AIM says and what controllers expect.

 

[Henning]

If you are given a pd decsent you can start and stop the descent at any altitude between 9 and 6 without saying anything. Once you have vacated an altitude you could not return to that altitude without permission.

That's my understanding, as long as you are heading down, you don't need to report anything. If you start back up for some reason, then you need to call. Checking in with a new controller I'll give him my altitude thru and cleared to.

 

[poadeleted20]

That's my understanding, as long as you are heading down, you don't need to report anything. If you start back up for some reason, then you need to call.

I've never seen that as a requirement or a recommendation. Can you point out where that's written?

 

[roncachamp]

The question is, can Cessna 12345 stop the descent on his own volition at some altitude above 6,000 or must he continue to 6,000?

The pilot can begin descent whenever he likes, can descend at any rate he likes, and can stop at any intermediate altitude he likes. What he cannot do is climb.

1. Do I have to ask for permission to stop a descent at an interim altitude once it has been initiated? If I do not have to ask permission, do I have to advise ATC?

No.

 

[vintage cessna]

What's the downside in ignoring this AIM recommendation?

Good question. I for one can not imagine any possible repercussions. It is easy to see the possible repercussions of just acknowledging reciept rather than repeating a clearance or instruction, but this I see none.

 

[roncachamp]

That's what happened to me. I'm on a CC and going near KRFD "C" at night (MAJOR UPS & FEDX sorting facility) thought I would be a nice guy and check in. I reported I was climbing after they said altitude "my discretion". I was "corrected" for reported it. It really took me by surprise. There was inbound cargo heavies coming in, I thought it would be a good thing to let them know, but obviously they could see me on radar.

KRFD TRSA

 

[roncachamp]

That's my understanding, as long as you are heading down, you don't need to report anything. If you start back up for some reason, then you need to call. Checking in with a new controller I'll give him my altitude thru and cleared to.

You should call before starting back up.

 

[kayoh190]

What's the downside in ignoring this AIM recommendation?

If you happen to be flying with an AIM Nazi, you have to listen to the resulting diatribe.

(speaking from experience)

 

[vintage cessna]

I've never seen that as a requirement or a recommendation. Can you point out where that's written?

If you think you can go back up once you start down on a pd, you may be confusing this with a cruise clearance.

 

[Henning]

I've never seen that as a requirement or a recommendation. Can you point out where that's written?

Nope.

 

[Henning]

You should call before starting back up.

Yeah, normally I would, but it only seemed to ever come up when I would be on a PD descent into SoCal and suddenly I'd be in an uncommanded climb on a mountain wave. "SoCal, 04Y is in an uncommanded climb, not sure where I'm stopping."

 

[vintage cessna]

Yeah, normally I would, but it only seemed to ever come up when I would be on a PD descent into SoCal and suddenly I'd be in an uncommanded climb on a mountain wave. "SoCal, 04Y is in an uncommanded climb, not sure where I'm stopping."

Well, I believe that to be incorrect. If for example, an acft at 9 was given a pd to 5, once 7 thousand mode c was displayed the controller could assign another aircraft 8 thousand. That wouldn't work very well if you could climb without further clearance. A cruise clearance is different however.

 

[peerlesscowboy]

If you think you can go back up once you start down on a pd, you may be confusing this with a cruise clearance.

If you don't report leaving your previously assigned altitude on a PD decent in a non-radar enviroment then ATC has no way of knowing you've descended, he/she can only assume that you're somewhere between your previously assigned and your new'ly assigned. So.......if you were at an assigned of 9000 and given "pilots discretion descend & maintain 6000", subsequently descended to and leveled at 7000 and then decided to climb back to 9000 yeah you could do that.

 

[peerlesscowboy]

Well, I believe that to be incorrect. If for example, an acft at 9 was given a pd to 5, once 7 thousand mode c was displayed the controller could assign another aircraft 8 thousand. That wouldn't work very well if you could climb without further clearance. A cruise clearance is different however.

You're assuming (incorrectly) that PD descents are only issued in a radar enviroment?

 

[peerlesscowboy]

.................... Or if this is one of those things where you're supposed to but don't have to... Thanks!

I think that's the case

 

[vintage cessna]

If you don't report leaving your previously assigned altitude on a PD decent in a non-radar enviroment then ATC has no way of knowing you've descended, he/she can only assume that you're somewhere between your previously assigned and your new'ly assigned. So.......if you were at an assigned of 9000 and given "pilots discretion descend & maintain 6000", subsequently descended to and leveled at 7000 and then decided to climb back to 9000 yeah you could do that.

Even non radar when given a pd you can not go up and down . True, ATC would have no clue unless you were instructed to make reports. On a cruise clearance, radar or no radar, you can go up or down within the defined parameters of the cruise clearance, unless the pilot chooses to verbaly report vacating an altitude. In which case, you could not climb back to or through that altitude without an ammended clnc.

 

[peerlesscowboy]

......... True, ATC would have no clue unless you were instructed to make reports.

that's the point I was trying to make ^^^^

 

[vintage cessna]

You're assuming (incorrectly) that PD descents are only issued in a radar enviroment?

Nope. A pd only gives you permission to go down, not up. A cruise clnc or a block altitude assignment would give you permission to go up or down. Radar or non radar is irrelevant.

 

[vintage cessna]

that's the point I was trying to make ^^^^

Ok, and the point I'm trying to make is what you are actually permitted/required to do.

 

[peerlesscowboy]

FWIW it seems to me that not reporting starting descent on a PD is a little like assuming a "pilots discretion" descent is the same as a block altitiude? That said, most people don't do it and my understanding is most controllers don't expect it.

 

[peerlesscowboy]

Ok, and the point I'm trying to make is what you are actually permitted/required to do.

OK, let's assume we're non-radar @ 9000, "pilots discretion descend & maintain 6000". If we don't report leaving our previously assigned 9000 at what point would you say that ATC can assume you vacated nine and assign another aircraft 9000?

 

[vintage cessna]

FWIW it seems to me that not reporting starting descent on a PD is a little like assuming a "pilots discretion" descent is the same as a block altitiude? That said, most people don't do it and my understanding is most controllers don't expect it.

No, nothing like a block a block altitude. If you are IFR in a radar environment and are at say 9000 thousand feet. The controller gives you a pd to say 7 thousand feet. You descend to seven thousand and say nothing, which is fine. Once the controller observes your mode c at 7000 thousand, another aircraft can be assigned 8000 thousand. That would be a real problem if you were allowed to climb without permission.

A controller will expect that once you start down on a pd you only level off or descend, never climb. This is different than a cruise clnc which is a type of discretionary decsent. But you will be specifically told to "cruise" .

 

[vintage cessna]

OK, let's assume we're non-radar @ 9000, "pilots discretion descend & maintain 6000". If we don't report leaving our previously assigned 9000 at what point would you say that ATC can assume you vacated nine and assign another aircraft 9000?

ATC wouldn't assume anything about your altitude without a report in a non radar environment. I'm not trying to determine what you can get away with as far as the rules go. Airline pilots that have been around for a while and are Savvy can pick up on when a controller actualy wants a pilot to lie about his altitude. If a controller has screwed up and is in a bind, a pilots verbal report of an altitude will trump the model c report, provided they are not ridiculously different.

 

[Velocity173]

OK, let's assume we're non-radar @ 9000, "pilots discretion descend & maintain 6000". If we don't report leaving our previously assigned 9000 at what point would you say that ATC can assume you vacated nine and assign another aircraft 9000?

Once you report leaving 8,000.

 

[LuisO]

That's my understanding, as long as you are heading down, you don't need to report anything. If you start back up for some reason, then you need to call.

I've never seen that as a requirement or a recommendation. Can you point out where that's written?

AIM 4-4-10 (c)

c. The term “AT PILOT'S DISCRETION” included in the altitude information of an ATC clearance means that ATC has offered the pilot the option to start climb or descent when the pilot wishes, is authorized to conduct the climb or descent at any rate, and to temporarily level off at any intermediate altitude as desired. However, once the aircraft has vacated an altitude, it may not return to that altitude.
....
EXAMPLE-
2. “United Four Seventeen, descend at pilot's discretion, maintain six thousand.”

NOTE-
2. The pilot is authorized to conduct descent within the context of the term at pilot's discretion as described above.

There is NO mention whatsoever in that (very specific "Pilot's Discretion" AIM entry) that the pilot should report leaving the altitude that he was just given leniency to leave!!!

So I really don't understand what the fuss is about here. It's very clear that there is no need to report it.

 

[Ghery]

I report when leaving my previously assigned altitude on a PD descent and SEA center has yet to complain. I've heard many an airline pilot do the same while I'm listening on ch 9 on UA and have yet to hear ATC complain. I'm not sure what the big fuss is all about.

 

[LuisO]

Other than congesting the frequency unnecessarily there should be no fuss. In the case of the OP I guess ATC was trying to direct him (us) to AIM 4-4-10 (c)

 

[roncachamp]

I report when leaving my previously assigned altitude on a PD descent and SEA center has yet to complain. I've heard many an airline pilot do the same while I'm listening on ch 9 on UA and have yet to hear ATC complain. I'm not sure what the big fuss is all about.

Complaining tends to take a bit more time than just saying "roger".

 

[vintage cessna]

I report when leaving my previously assigned altitude on a PD descent and SEA center has yet to complain. I've heard many an airline pilot do the same while I'm listening on ch 9 on UA and have yet to hear ATC complain. I'm not sure what the big fuss is all about.

If you read what the OP wrote, he didn't say ATC complained or were criticizing him, just that they were confused. Someone else, who has a habit of confusing the issues made the claim that ATC was being critical.

The only really big fuss is that is was revealed in subsequent discussion that some people think you can not only descend but climb also in pd descent.

 

[LuisO]

You're assuming (incorrectly) that PD descents are only issued in a radar enviroment?

Why is his assumption "incorrect" ? Do you have any reference?

Seems like a very plausible assumption that ATC will only issue these PD clearances in a radar environment, especially when AIM 4-4-10 (c) has no specific requirements for reporting anything (other than the required acknowledgement of the clearance).

 

[Velocity173]

Why is his assumption "incorrect" ? Do you have any reference?

Seems like a very plausible assumption that ATC will only issue these PD clearances in a radar environment, especially when AIM 4-4-10 (c) has no specific requirements for reporting anything (other than the required acknowledgement of the clearance).

6-6-2 of the controllers manual. Post # 70.

 

[MikeELP]

Complaining tends to take a bit more time than just saying "roger".

 

[roncachamp]

Why is his assumption "incorrect" ? Do you have any reference?

Seems like a very plausible assumption that ATC will only issue these PD clearances in a radar environment, especially when AIM 4-4-10 (c) has no specific requirements for reporting anything (other than the required acknowledgement of the clearance).

Discretionary climbs or descents are not just those that include the phrase "at pilot's discretion". When an aircraft is instructed to be at a specified altitude over a specified fix, that portion of the climb or descent is discretionary. Some examples:

"Waco 01V, cross Smallville VOR at and maintain 6000." The pilot can begin descent at any time and descend at any rate provided he reaches 6000 not later Smallville VOR.

"Waco 01V, cross Smallville VOR at or below 8000, descend and maintain six thousand. The pilot can begin descent at any time and descend at any rate provided he is no higher than 8000 when he reaches Smallville VOR. Once he reaches the VOR the descent is no longer at pilot's discretion.

Descents like these are common in non-radar environments.

 

[frfly172]

Another p****** contest over nothing. Acknowledge the instructions and comply.

 

[vintage cessna]

That's my understanding, as long as you are heading down, you don't need to report anything. If you start back up for some reason, then you need to call. Checking in with a new controller I'll give him my altitude thru and cleared to.

That is good practice. If you are switched from one ATC facilties jurisdiction to another's, if you don't check in with what your altitude is or what altitude you are leaving, there will have to come back and ask you because they need to verify the accuracy of your mode c. Stating your assigned altitude, if you are transitioning to an altitude, could also catch a mistake someone has made.