Vacating altitudes

[A Squared]

Here's one:
Yesterday, my student and I were decending into Socal. They cleared us for a STAR about 20 miles from the first VOR. A little while later, we reach the first point of descent on the STAR, and my student starts to descend without a radio call. "Let them know you're leaving 8000," I said. He did, and they told him to stay at 8000.

Hence, we acknowledged a clearance, but that didn't mean we could descend without letting the controller know, especially where we didn't reach a point of descent until several minutes after the clearance was recieved.

To expand on Booker's question, did you get a clearance to fly those altitudes? It's hard to tell for sure from your post. If you're not clear on the matter, if you have been cleared for the XXXXX arrival, that is a clearence to fly the horizontal track of the STAR at your previously cleared altitude. In order to descend to the published altitudes, you must be cleared to "descend via the published altitudes" or words to that effect.

If your instructions were only to "fly the XXX arrival" then you were not cleared to decend out of 8,000 ft.

 

[nosehair]

Just to clarify, you must have been issued a "descend via" clearance, right?

Doesn't matter. From a practical standpoint, it is just plain good operating practice to inform ATC "when leaving an assigned altitude".
Expect the unexpected. Plan on mistakes and changes from prviously assigned instructions. Report when changing altitudes.

It has happened a *few* times, in my experience, that when making an altitude change and reporting that change, that ATC says "Wait, maintain that altitude". So why not do it? Adds another level of safety.

BTW, that's not quite the same as repeating a newly assigned heading, IMHO.
A heading change is much more noticable than an altitude change. And the AIM says "when leaving an assigned atitude".
For a reason. More accidents have occured from misunderstanding altitude assignments than from heading change misunderstandings.

What we are, or should be, talking about is the possibility of human error, not legalese.

 

[A Squared]

I respectively disagree, if a controller issues a clearance that is to be complied with I would assume that a readback of the altitude cleared to and my tail number is proof that I as the pilot have received and will comply with the new clearance. Same with vectors, if I am given a vector say 270 a repeat of that vector plus my tail number to me indicates that I understand and will comply with the new vector. I would not say in my readback that I am now turning to 270.

Of course you don't report "vacating" a heading, there is no requirement to do so. There is however a specific requirement to report vacating an altitude. You need to spend a little time in the AIM. I suspect that you don't have one, so I'll quote the parts you're confused on:

4-4-6. Pilot Responsibility upon Clearance Issuance

a. (not pertinent to the discussion)

b. ATC Clearance/Instruction Readback. Pilots of airborne aircraft should read back those parts of ATC clearances and instructions containing altitude assignments or vectors as a means of mutual verification. The readback of the "numbers" serves as a double check between pilots and controllers and reduces the kinds of communications errors that occur when a number is either "misheard" or is incorrect.

Read that carefully. This is the part of the AIM which instructs you to readback assigned altitudes and vectors. This is the readback part, it applies to altitudes and headings. This is the guidance you are following when you say, Roger, descend and maintain 8000, 1234BX

Now, skipping forward in the AIM we have:

5-3-3. Additional Reports

a. The following reports should be made to ATC or FSS facilities without a specific ATC request:

1. At all times.

(a) When vacating any previously assigned altitude or flight level for a newly assigned altitude or flight level.

Now, ask yourself, if 5-3-3(a) really just means "readback your assigned altitude" , why would they even bother to waste the ink? You are already instructed to readback your altitude in 4-4-6(b), so if 5-3-3(a) really just means "readback your altitude" it is pointless and unnecessary.

Answer, 5-3-3(a) really *does* mean report vacating the altitude, just like the words say, it does not actually mean "readback the new altitude"

Look, whether you believe that the guidance of 5-3-3(a) is mandatory, optional, advisory, merely a courtesy, or whatever ....the idea that reading back an altitude assignment statisfies the AIM guidance to report vacating an altitude is just silly, absurd even. The words are very clear and understandable, no jargon, no obscure latin phrases, just simple plain English.


Look, I would again encourage you to read the Avweb articles written by Don Brown. These articles were written with precisely you in mind, pilots who create unnecessary work for controllers because they don't understand correct communication. In one (or even several) of those articles he explains, in detail, why this report is a good idea, and it will be abundently clear why reading back an altitude assignement is not the same as reporting vacating the previously assigned altitude.

 

[Booker]

Doesn't matter. From a practical standpoint, it is just plain good operating practice to inform ATC "when leaving an assigned altitude".

That's nice. But that wasn't my point. I wanted to clarify that time builder had been issued a "descend via" clearance for the STAR they were flying. The message implied they were descending via STAR altitudes, but like A Squared writes, being cleared for a STAR does not also clear one to descend via the STAR altitudes. That's what I addressing, not mic-keying protocol.

 

[time builder]

My mistake, they didn't say "descend via," so making the report saved us. Thanks for the clarification.

 

[zbwmy]

Quote:
It does not state anywhere in the 7110.65 that aircraft must state their assigned altitude on every freq check in. The first Center sector checks the mode C. It seems all American pilots report altitude climbing, decending, level, on every check in. Only about half the foreingers do. It sounds odd when you only hear "Boston Center AZA692". I insisted they had to state their altitude, but looked it up and cannot find it.
by zbwmy
From 7110.65

Quote:
5-2-18. ALTITUDE CONFIRMATION- MODE C
Request a pilot to confirm assigned altitude on initial contact unless:
NOTE-
For the purpose of this paragraph, "initial contact" means a pilot's first radio contact with each sector/position.
a. The pilot states the assigned altitude, or
b. You assign a new altitude to a climbing or a descending aircraft, or
c. The Mode C readout is valid and indicates that the aircraft is established at the assigned altitude, or
d. TERMINAL. The aircraft was transferred to you from another sector/position within your facility (intrafacility).
zbwmy, is this what you were looking for?

5-2-18 does not tell me a pilot must check in with his altitude if level. Under
c. The Mode C readout is valid and indicates that the aircraft is established at the assigned altitude. This mode c has already been validated by a previous sector.