Unclear Clearance

On 11/27/2005 9:30 PM, Daniel Roesen wrote the following:
* Ron Rosenfeld :

From the (US) AIM:


Thank you very much for citing the relevant regs. Is this stuff available
online for future reference?


Some of that stuff is hard to find but virtually everything
the FAA publishes is available on line. Here is a links
page that has a lot of it:

http://www.clubcherokee.com/links/

Look towards the lower left for the FAA stuff. I find the
searchable FAR database at risingup.com to be particularly
handy.

"Daniel Roesen" wrote in message
...

Thank you very much for citing the relevant regs. Is this stuff available
online for future reference?


The AIM can be found online at:

http://www.faa.gov/atpubs/AIM/index.htm



Hm... interesting. "optimum rate consistent with the operating
characteristics of the aircraft". This is fuzzy.

The most economically way to descend a jet is at near idle thrust,
tactically. But strategically, that's only true if I'm on my computed
economic descent path. So if ATC orders me earlier than reaching my ToD
to "descend now FL270", at what rate do I descend? "optimum rate"
would be very shallow and be not quick enough for the controller who
wants to get me out of the way of something. Should I descend at near
idle thrust? But that would bring me down much quicker than strategically
economic, as I have to fly a longer distance on a suboptimal low flight
level.


When the descent is to avoid other traffic, as it is whenever "descend now"
is used, quicker is better than slower.

"Daniel Roesen" wrote in message
...

Hm. I'm lacking any real world experience, but in our little wannabe Sim
world (VATSIM) I'm used to crossing restrictions like "XYZ, descend FL120
(to be) level(ed) at FIX" which is to be interpreted as "start descent
now with at least 1000fpm and be at FL120 latest at FIX". This is for
Europe and confirmed to be real-world compatible by several real-world
ATC controllers here. Now I happen to like "flying" in US airspace, where
instructions like "XYZ, cross CEDES at 11000ft" are used. Is that to be
taken analogue to European interpretation to start descending to 11000ft
_now_, or to be taken as "descend 11000ft at own discretion"?


It means the pilot can begin descent at the time of his choosing and use the
descent rate of his choosing so long as he reaches 11,000 feet not later
than CEDES.



If the latter, does ATC expect a report like "leaving FL240 for 11000" if
not
explicitly requested?


No.



What is the US equivalent of the European
clearance to "descend now to X with 1000fpm or more, to be level at
FIX"? Is there any at all (short of a full "descend and maintain 11000ft,
1000fpm or more, cross CEDES at level")?


There is no equivalent standard US phraseology.