(endre) writes:

I was being radar vectored for the SHN NDB approach. I was cleared
in the following way: Cessna 61786 14 miles from NDB descend and
maintain 2000 until established.

The problem: I was outside the 10 mile ring on the plate, established
on the inbound course, no way to tell when I would be inside 10 mile.
However, I would need to descend to 1400 before the NDB to have a
chance to descend to MDA of 900.

What would you all do?

Since you were being vectored and not flying a full procedure, I'd
guess that you were OK to descend as soon as you intercepted the
inbound course, but if in doubt I would have asked ATC to clarify (as
I often do -- better embarrassed than dead). In my real-life IFR
flying so far, I've noticed that ATC often vectors me onto the
approach path far out beyond the PT limits -- once so far that I could
just barely pick up the localizer (in night IMC no less) -- and that
they intend for me to follow any altitude instructions as soon as I'm
on the course, even if I won't be inside PT limits for another 10
minutes or more.

Even if my experience is unusual (or U.S. ATC works differently, and
"established" means explicitly "inside PT limits"), they still gave
you the information you needed -- you were 14 nm from the NDB, and
with a 90 kias approach speed, 3 minutes (4 with a strong headwind)
should have been good enough to ensure that you were inside the 10 nm
circle.


All the best,


David