On Mon, 22 Nov 2004 13:59:04 -0800, "Peter Duniho"
wrote:

"Chris" wrote in message
...
[...]
With the 182, it is 80 knots turning from the 45 to downwind, 75 on base,
and 70
on final. I don't understand why pushing the prop to full flat has any
noise
effect whatsoever.

Exactly

Exactly, except for those airplanes that cannot maintain level flight at
pattern speed with gear and flaps out at final descent power settings.


You should hear me on a circle to land. Gear out, bout 20-25 deg of
flaps and go to cruise power until within about 30 degrees of the
landing runway heading. Then back to about 12" and full flaps. Turning
with everything hanging out while maintaining altitude takes about
22-23" of MP at 2400 RPM. At that power setting and low altitude
~500' AGL I try to keep it over the airport for the full circle to
land.

Which is, by the way, all airplanes with a constant speed prop. The power
setting for final descent is necessarily lower than that required for level
flight within the pattern, even if you slowed ALL the way to your final
approach speed. RPM will thus be higher, assuming the pitch is set to full
fine pitch (high RPM). Higher RPM means more noise.

For a VFR pattern: On my old Debonair they taught; slow to 110-100 on
down wind, 90 on base and 80 minus 1 MPH for each 100# under gross on
final. This produces quite a steep final, but with the consequences
of a relatively short roll out.

I generally start the descent after gear down at the end of the runway
on down wind. Prior to that with the old 2-blade prop would have been
noisy.

Some airports want you to keep pattern altitude much longer. Some till
you start final.

I would add that I'm usually coming down hill just prior to the 45
entry (pattern alt one to two miles out) and the Deb takes its time
slowing down. I probably have the MP back to the point where the prop
is already turning slower prior to pattern entry.

Sooo... power is back (but a long way from idle) prior to pattern
entry, down wind is basically low power (16"-17")with the Deb slowing
down. Gear down at the end of the runway and a bit of flaps down to
about 100 MPH, MP about 12". Turn base, add flaps, retrim for the
slower speed of 90, Turn final, full flaps, speed ~75-80, prop full
in. Adjust MP to maintain aiming point.

Actually if I enter a bit on the fast side while slowing down I use
less power in the pattern than I would if I entered the pattern at 110
as I'd have to apply power on down wind while I'm normally reducing
power.

If I didn't put the gear down until I had the runway made it'd be one
mighty big pattern power off. Almost as big as some of the local
Cessnas and Cherokees fly. (sorry, I couldn't help it) :-))

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com
If Jim's 182 flies along level in the pattern at the same airspeed and prop
RPM that he uses for final descent, I have no idea how he accomplishes a
final descent at all. A plane like that would be stuck up in the pattern
indefinitely.

Pete