A Lieberman wrote:
When an airport has multiple approaches, like GPS, ILS, VOR and so on, and
lets say ceilings are above the GPS minimums, will Center automatically set
you up for the most precise approach available such as an ILS, or do you
have to request it.

For the most part, if there's an ILS at an airport that makes sense for the
prevailing wind direction, they'll be using that in preference to any other
type of approach. If the airport has an ATIS, they'll be advertising which
approach is in use there.

If you want to use some other approach, it's best to tell the first
controller you check in with from the approach facility that owns the
airport (if center is running the approaches, tell the guy who's on the
frequency listed on the approach plate as the approach control frequency).
Or, just tell whoever you're talking to when you're 20 miles out.

If you want to use some other approach which has roughly the same FAC as
the one being used by default (say, the GPS-22 instead of the ILS-22),
that's a no brainer. If you want to use some approach running differently
from the major traffic flow, you may have to wait until they can work you
in if it's busy.

If you should need to request a particular approach, when do you request
it? Especially at uncontrolled airports such as PIB (Hattiesburg/Laurel
MS). Can the approach be requested at the time I file with FSS?

In theory, you could tell FSS to put the approach name in the remarks box
on the flight plan, but I'm not sure it's worth the effort. It's easy
enough to just request what you want on the air. It's also easier to
predict what the weather is when you're 20 miles out then when you're on
the phone with FSS a couple of hours before.

Is it assumed you will be provided vectors by center or should one assume
that full procedure approaches are in order? I know you can request full
procedures, but what is the "default" or "expected" from ATC's point of
view?

If they have radar coverage in the area, ATC tends to prefer to give
vectors. If you want the full procedure, just ask for it.