On Wed, 29 Jun 2005 19:56:38 -0400, "Morgans"
wrote:


"gregg" wrote in message
...

I have often wondered about inertia and twins in general:

with the engines off the centerline was it harder to get a twin into a
roll, and harder to stop?

Saying nothing of P effects, and torque, it is the fact that a object with
most of it's weight at the center is easier to spin. Think of the figure
skater pulling the arms in. She started with arms out, slowly. Arms in,
the same energy spun her faster.
--
Jim in NC

What you say is true Jim, but in WWII, it wasn't the configuration of
the airplane that limited fighter maneuverability so much as how the
controls stiffened up at speed.

Take for instance the Mitsubishi A6M-21 Type Zero fighter, the famous
Zero. Looking at the wings you will notice that the ailerons extend
nearly all the way from the wingtips to the base. The length of the
aileron looks a lot like the typical unlimited aerobatics airplane of
today, only it had no spades to assist it.

You don't have to be an aerodynamics engineer to look at that and just
know that that configuration would be hard to deflect at high speeds.
And that's exactly what happened. Navy pilots flying Grumman F4F
Wildcats learned early on that they could escape a tough situation by
diving and rolling at high speed because the Wildcat's controls did
not stiffen up as much as the Zero's.

Both the Spitfire and Messershmitt 109's suffered stiffening controls
at high speeds to the point where at high speed (near 400 mph), it
took 4-5 seconds to bank from one 45 degree bank to the opposite 45
degrees and most pilots had to use both arms to push against the stick
to accomplish this. Just think about that and put that image in your
head of pushing against the stick and then counting the seconds. A
high speed dogfight must have looked like the airplanes were banking
in slow motion.

Given that situation, ANYTHING that lightened up control forces was
going to give a significant advantage to the pilot of that airplane.
Brute strength and stamina were likely a factor in a maneuvering fight
early in WWII.

So when the P-38 got hydraulically boosted controls, the pilot was
able to deflect the ailerons with a lot less effort, and the airplane
could bank and turn faster than many single engine fighters with
unboosted controls despite it's large size and twin engine
configuration.

Corky Scott