ShawnD2112 wrote:

> loops is to pull about 3.5-4 gs at the bottom

Just under 4 G's seems to work very well for a "normal" loop
in the Pitts, which I believe, you, Peter and I all fly :)

It's all a matter of your entry airspeed, and how big a
loop you want to fly, and how much energy you want to spend.

For example, in the S-2B, I can loop starting at anywhere
from 120 to 210 mph.

A loop with an entry speed of 120 mph must be flown
very precisely, with less than 4 G's, and there is
little room for error, otherwise you will either stall
in the pull (if you pull too hard) or run out of airspeed
on the vertical upline (if you don't pull hard enough
and try too fly too large a loop that you just don't
have the energy for).

A loop with an entry speed of 210 mph can be flown
with a light (eg 3) G entry, which results in a big
loop with a large radius. Or it can be entered with
a lot of G which results in an (admittedly subjectively)
ugly little loop which costs you energy. Both loops
enter and exit at the same altitude, but the low G
loop exits with a higher airspeed than the high G
loop.

As the man says, you can spend it on the (vertical)
lines, or you can spend it in the corners.

High G pulls, which I do admit nicely square off
the corners, involve large angles of attack to
generate the large amounts of lift required to
pull the G. However, there is a tremendous amount
of drag produced at those high angles of attack, so
unless you have a very powerful engine and a large
diameter propeller, high G pulls are going to reduce
your total energy, requiring you to constantly lose
altitude during a sequence to keep your airspeed up.

--
aboyd@igs.net ATP

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