In article et,
"Dudley Henriques" writes:
Thanks much Pete. This training manual supposedly says that the 51 can't
hold a slip due to aileron or rudder issues that make it straighten out
if the pilot tries to hold it in a slip.
I've done hundreds of slips to both sides in this airplane and never had
such an issue. I'm assuming the training manual was written as an aid in
transitioning low time pilots into the high performance 51, as the dash
one specifically states that slips are not an issue.
The 51 does pay off fairly quickly on landing if you get it too deep
into the left side before touchdown and it can be a bit hairy. You
generally wouldn't hold a slip in the 51 under 200 agl for safety
reasons, and between the last flap position drag index and running the
prop up to low pitch, you really don't need slips in the 51, but I'm
really interested in researching the obvious conflict between the
training manual, the dash1, and my own personal experience in the
airplane along with every other 51 driver I have asked about this.
Thanks much for the help. I'll watch the thread for you.

Dudley,
Here's what I have. From AAF Manual 51-127-5, "Pilot Training Manual
for the P-51 Mustang", 15 August 1945.

Page 66:
"The P-51 does not hold a sustained sideslip. The aileron control is
not sufficient to hold the airplane in a sideslipping angle. However,
you can sideslip it long enough to avaid enemy fire in combat. When
any sideslipping is attempted, be sure to recover completely above 200
feet."

In truth, that sounds a bit fishy to me, as well. Of late, I've been
wading through the incredible amount of Tech Reports that have been
made available on the NACA Tech Reports Server. (About 10,000 inindexed
files. I'm not complaining. Indexing them is a huge effort, and I
_like_ roaming through huge reams of extreme Aero-Geekery. Color me
strange.) Among them are the reports on the wind tunnel test series
that were run to prove out the extended fin used on the P-51H (And the
Temco TF-51Ds from the 1950s, and the Cavalier '51s). They show that
for the P-51D configuration, with the great big long nose, the
direction stability's a bit weak at low speeds. (Not bad, mind, but
they wanted it better) Even though the '-51's ailerons get a bit mushy
when slow, that ahouldn't have been a problem.

I've also got a copy of the report of the modern-era flight tests
comparing the F6F, P-51, P-47, and F4U by John Ellis and Chris Wheal
that were published in _Cockpit_. (The journal of teh Society of
Experimental Test Pilots)

I regards to sideslip behaviour, they make this comment:
"Steady heading sideslips in cruise and land configurations revealed
nothing out of teh ordinary beyond the fact that the rudder forces in
both the Hellcat and Corsair were extremely high. Full rudder
sideslips generally required 50-60% of available aileron deflection in
cruise at 180-190 kts, and 20-50% aileron in the landing
configuration."
That doesn't sound like it can't sideslip to me.

There is one thing in the _Cockpit_ article that I find a bit odd.
They rate the P-51 as being rather heavy in pitch. According to their
data, they measured 'bout 20 lbs/G. That doesn't seem right to me -
from other data, I'd have thought that about 6 lbs/G would have been
more like it. Now, I know that late-model P-51Ds had bobweights in
the pitch system to help counteract the really light forces that you
got with an extremely aft CG, such as when the fuselage tank was
installed & filled. Would having the bobwights in the airplane with a
forward CG heavy things up to that extent? Or could hte airplane have
been out of rig? (If it helps, the P-51D they used for the tests was
N51HT, Harry Tope's airplane.


--
Pete Stickney

Without data, all you have are opinions