Vacating altitudes

[surveypilot]

Pilot's Discretion

From the Pilot/Controller Glossary:
"PILOT'S DISCRETION- When used in conjunction with altitude assignments, means that ATC has offered the pilot the option of starting climb or descent whenever he/she wishes and conducting the climb or descent at any rate he/she wishes. He/she may temporarily level off at any intermediate altitude. However, once he/she has vacated an altitude, he/she may not return to that altitude. "

When you accept the Pilot's Discretion clearance you are reporting that you are leaving the previously assigned altitude and meeting the AIM's reporting requirement. If you decide to delay the descent, an additional report is not required, and only serves to congest the frequency more.

 

[avbug]

Accepting a PD clearance does not constitute reporting vacating an altitude. Accepting a PD clearance to a lower altitude, and then starting descent for that lower altitude ten minutes later, one has not vacated one's altitude until starting that descent...ten minutes later.

A long time ago an aircraft talking to approach experienced a lightening strike and reported it to ATC with "XXX approach, XXX has been struck with lightening. We are descending in flames."

ATC responded, "Roger XXX, cleared to descend."

Gotta report. Gotta report. Gotta report. Gotta talk. Gotta talk. Gotta talk. Gotta...

 

[A Squared]

[/B]surveypilot;1130449]
When you accept the Pilot's Discretion clearance you are reporting that you are leaving the previously assigned altitude and meeting the AIM's reporting requirement.

Absolutely not A pillot's discretion descent means exactly that, you descend at the pilot's discretion. This is stated very clearly in hte definition you quoted

".......ATC has offered the pilot the option of starting climb or descent whenever he/she wishes.........."

It doesn't get much clearer than that

 

[zbwmy]

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.

 

[PA31Ho]

What about assigned headings? For instance if ATC says fly heading 340.. then 5 minutes later they switch you to next center, are you REQUIRED to tell them your heading? It's probably helpful so they don't forget about you.

 

[avbug]

You should inform ATC during a handoff of a heading assignment.

I've been handed off before and didn't mention it, droned along mindlessly for a short while until ATC asked where I was going...the vector didn't get handed off with me.

"XXX one-six thousand, heading zero niner zero."

No muss, no fuss.

 

[ksu_aviator]

http://www.faa.gov/ATpubs/AIM/Chap5/aim0503.html#5-3-3

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.
(b) When an altitude change will be made if operating on a clearance specifying VFR-on-top.
(c) When unable to climb/descend at a rate of a least 500 feet per minute.
(d) When approach has been missed. (Request clearance for specific action; i.e., to alternative airport, another approach, etc.)
(e) Change in the average true airspeed (at cruising altitude) when it varies by 5 percent or 10 knots (whichever is greater) from that filed in the flight plan.
(f)The time and altitude or flight level upon reaching a holding fix or point to which cleared.
(g)When leaving any assigned holding fix or point. ​

___________________________________________

91.183 IFR radio communications.​

http://ecfr.gpoaccess.gov/e/ecfr/graphics/ret-arrow-generic-grey.gif top ​

The pilot in command of each aircraft operated under IFR in controlled airspace shall have a continuous watch maintained on the appropriate frequency and shall report by radio as soon as possible—
(a) The time and altitude of passing each designated reporting point, or the reporting points specified by ATC, except that while the aircraft is under radar control, only the passing of those reporting points specifically requested by ATC need be reported;
(b) Any unforecast weather conditions encountered; and
(c) Any other information relating to the safety of flight.

___________________________________________

http://www.faa.gov/Atpubs/ATC/ATC.pdf​

Do not draw a horizontal line through an
altitude being vacated until after the aircraft has
reported or is observed (valid Mode C) leaving the
altitude.
___________________________________________​

Ok, I linked all of that stuff for a reason. The AIM states that vacating an altitude "should" be reported every time. Part 91, however, does not specifically list altitude reports as mandatory. It does mandate that any information pertaining to the safety of flight be reported. Because ATC uses pilot reports to verify Mode C during initial contact, the case could be made that ATC does not trust Mode C for altitude changes.

Every altitude change is verified by ATC. Usually the verification comes by way of the clearance read back.

ATC: N123AB climb and maintain tree thousand
N123AB: Climb and maintain tree thousand.

When the Mode C for 123AB shows level flight, ATC will verify that it reads 3,000 (corrected for non standard pressure). If it does not read 3,000, ATC will verify the assigned altitude with the aircraft. The same holds true for descents and frequency changes. At all times, the pilot will help ATC to verify the correct Mode C output.

Verification of the Mode C is the most likely reason that the AIM lists leaving an altitude as a mandatory report. Should the pilot choose not to report leaving an altitude and the Mode C output does not operate correctly the controller has no way of knowing that the Mode C is unreliable.

Therefore, reporting vacating an altitude is a "safety of flight" issue. With out the report, the unreliable Mode C may lead a controller to issue a clearance that does not meet the sepration standards. This holds true for all types of altitude changes, whether the altitude change is suppose to be immediate or discretionary (crossing restriction climbs and descents are discretionary with limits).

Also, frequency congestion is a really lame excuse for not making a mandatory radio call, whether or not you believe the call is regulated by FAR or advised by AIM.

 

[avbug]

Reporting vacating an altitude is a courtesy issue. It may or may not be a safety of flight issue.

 

[ksu_aviator]

Yes it is. Reread the above.

Mode C is not considered reliable. The only way to accurately determine and aircraft's altitude is to query the pilot and cross check that altitude with the Mode C indication.

If Mode C was reliable we wouldn't be verifying the indication as often. In fact, there is not a time in which Mode C goes unverified by a pilot report. Not one single climb or descent goes unverified. That speaks volumes to the distrust that ATC and the FAA have for the Mode C output.

 

[avbug]

You're far into the speculative left field with that...you don't know what you're talking about.

ATC has proceedures. Reporting altitude changes is a proceedure, and in this case, really a courtesy. ATC and the FAA does not have an inherent distrust of mode C. Where you came up with such a ridiculous idea, one an only guess.

I can just imagine an ATC version of the Verizon guy, constantly saying "Say your altitude now." "Can you tell me how high you are now?" "Now?" "How about now?" "Say altitude now." Gee wilbur, it might have changed in the last ten seconds, how about now? Sir, I'm going to need you to give me a blow by blow account of your altitude because I have a deep distrust of Mode C. I actually lose quite a bit of sleep over it.

Get real.

XXX, descend and maintain flight level three three zero.

Cleveland, XXX descend and maintain flight level three three zero.

Cleveland, XXX is leaving flight level three five zero for level three three zero.

Thank you.

Cleveland, XXX is now two hundred feet into the descent below light level three five zero, descending three three zero, with eighteen hundred feet, no, make that sixteen hundred feet to go now.

Roger.

Cleveland, XXX, we're showing flight level three four four and sixty six feet. What altitude are you showing for us?

XXX, Cleveland shows you flight level three four zero.

Cleveland, roj, that matches, we're now two hundred feet below that, descending three three zero, doing three seventy five knots.

Roger.

Cleveland, XXX is three three five, descending three three zero, my shirt is white with blue epaulets, I am five foot nine and three quarters, I have brown hair, blue eyes, and prefer blondes who can speak czech, and my sign is scorpio.

Roger, XXX

Cleveland, XXX is almost at three three zero, I nearly levelled there briefly just a little early, leaving three three three for three three zero. Speed has increasesed slightly from my previous report, and my dislikes include people in Starbucks who order more than two cups of lattè and change their mind at least six times.

Roger, XXX.

Cleveland, XXX is level at three three zero, plus five feet.

Roger XXX, Cleveland shows you level three three zero, thank you for keeping me informed. I have an inherent distrust Mode C, your reporting has helped immensely.

Cleveland, XXX. No worries. We are now one hundred feet high and wish to advise that it is my copilot's fault, but are returning to our assigned altitude.

XXX, Cleveland, thank you.

Cleveland, YYY with emergency traffic. Five minutes ago we experienced left wing separation and have departed our assigned altitude.

YYY, Cleveland, understand you are no longer maintaining three seven zero. Say intentions.

Cleveland, YYY is unable to maintain controlled flight, and estimate terrain impact in two minutes thirty seconds, presently descending through flight level two two zero.

YYY, understand wing separation. Understand you plan on striking the ground directly beneath you, is that correct?

Cleveland, YYY, that is correct.

YYY, Cleveland, roger. Say altitude you intend to terminate this flight.

Cleveland, YYY, we believe terrain elevation to be five thousand.

YYY, understand your descent will stop at five thousand. Be advised if you intend to go lower, and also be advised my radar stops at one five thousand.

Cleveland, YYY understands, we will maintain five thousand upon impact.

YYY, cleveland, say altitude now?

Cleveland, YYY is passing one seven thousand, descending five thousand.

YYY, Cleveland, stand by to copy center number regarding altitude deviation.

Cleveland, YYY is unable, and cockpit pen has been pinned out of reach due to centrifugal force. We're sorry about not reporting leaving altitude earlier, we were unable to break through the traffic.

YYY, Cleveland, altimeter 29.96. Advise centrifugal force and not centripetal. Understand traffic, but understand I have an inherent distrust of Mode C. Say altitude.

Clevelad, YYY is passing one three thousand, corrected centripetal. Altitude has been fairly spot-on so far.

YYY, contact next controller on 133.85.

One three three eight five, good day sir.

Cleveland, YYY checking in niner thousand descending five thousand, with second wing separation.

YYY, Cleveland, good day, understand second wing has left you. Be advised I'm unable five thousand. For now, descend and maintain seven thousand. Say altitude leaving.

Cleveland, YYY is six thousand three hundred, unable seven thousand, with request.

YYY, Cleveland, go ahead with request. YYY? YYY?