"Teacherjh" wrote in message =
...
Well, lets ask the controllers here (rather than AIM, which we all =
have access
to). On a cruise clearance, for example Cruise 6000, you observe =
(mode C) an
aircraft has descended from 6000 to 4000. There is another aircraft =
which
could use the 6000 altitude. You've received no communications from =
the
aircraft on a cruise (except the acknowlegement of the clearance). Do =
you
consider the 6000 foot alititude vacant?
=20
Same question, but the cruise aircraft has reported descending to =
4000. Has
his report of a descent vacated the 6000 foot altitude? (no bobbing =
back up)
=20
Same question, but instead of a cruise question, it's a "descend at =
pilot's
discretion to 2000". The pilot acknowleges the clearance, and later =
is
observed at 4000 feet, having not reported the descent.
=20
Same question, same airplane, but in this case the pilot reported =
descending
from 6000 to 4000.
=20
So, in which cases does 6000 no longer belong to the pilot, in your =
eyes and
actions?
=20
Jose
=20

In my experience, if the controller needs an altitude I will be =
vacating,
I'll either not get a Pilot's Discretion descent, or else I'll get a =
request to
"Report leaving altitude or flight level".
I like it that way. There's less opportunity to misconstrue intentions.
---JRC---