Confusion about when it's my navigation, and when it's ATC

"Mxsmanic" wrote in message
So it would probably be best to set the MCP to prevent any descent
until I'm cleared, then?

MCP = max continuous power? Sorry- not familiar with the term as used on an
FMS. The important thing is to not set the altitude hold for descent until
cleared by ATC.

In simulation, too, even though traffic is sometimes too light to
justify it (the ATCs need practice as well). In fact, it seems that I
almost never follow the arrival procedure as published. Often just as
I'm beginning it, ATC gives me other instructions. I suppose it's a
bit of a relief as then all I have to do is follow their instructions,
rather than try to follow the arrival chart (but if the FMC is doing
it, it's easy).

A good center controller will have all of the arrivals spaced like pearls
before everyone hits the arrival's gate. That way everyone can follow the
arrival as charted with ATC isssuing speed changes to maintain spacing.

Is there a specific phrasing that means "you can do your own lateral
AND vertical navigation"? Or does ATC as a rule never let IFR flights
select their own altitudes?

The most common is a clearance to cross a fix at an assigned altitude
(crossing restriction). Say for example you are cruising at FL290 and the
controller isues you a clearance to cross a fix at 12000'. It is your
perogative as to when to start your descent so long as you cross the fix at
the assigned altitude.

During the climb, ATC sees the final altitude we requested on our flight
plan. They try to get us up there, traffic permitting. After that we request
from ATC any altitude changes we want and they work us to that altitude,
traffic permitting.

What does ATC say if they want you
to follow everything on the plate, including the indicated altitudes?

"DESCEND via the Korry 3"

Did your colleague get into significant trouble?

No, because seperation wasn't lost.

OK, so should I say something like "leaving FL290 for 12000 at CLARR,"
assuming I'm already cleared to descend at my discretion?

Sounds professional.

So there is no equivalent of "resume own navigation" for altitude,
like "resume own altitude," or whatever?

In the IFR world, altitude is all important. There are crossing restrictions
and block altitudes, but most of the time we follow

If ATC regularly overrides the plates and (apparently) doesn't often
clear anyone to follow the altitude indications on the plates, why do
all the approach plates seem to mention altitudes? Just for radio
loss?

In the real world we usually follow the arrival procedures with the
altitudes as published. When flying the big jets, just remember that you
will need 3 miles for every 1000' you want to descend plus another 5 miles
to slow for the 250 knot speed restriction at 10000'.

D.