Leaves me quite pensive given that our field is at 8500'. The instructors
won't do spins up here.
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of
rparigor@suffolk.lib.ny.us
Sent: Tuesday, August 05, 2008 11:44
Subject: RE: Europa-List: Re: Spins
Hi William
"> I would thoroughly concur. I did an unusual attitudes course in St
> Augustine in an extra 300 and would thoroughly recommend it. great fun
and
> huge confidence builder."
I agree that it is a great idea to get spin training first hand.
The only thing I would like to add is that just because you spun in a
plane many times does not mean you know exactly how the plane you are
flying may exactly react as far as spin entry and recovery???
Many know that with all other things the same (weight and air density) a
more aft CG will make spin entry easier and a spin harder to recover than
with a more forward CG.
Some know that with all other things the same (Air density and CG) the
heavier the weight of the aircraft spin entry will be easier and harder to
recover from a spin than in a lighter weight aircraft.
Fewer yet know that all other things the same (Weight and CG) that the
thinner the air spin entry will be easier and harder to recover from a
spin compared to flying in thicker air. Air will get thinner the higher
you go, the warmer the air, and the more moist the air is. If you know how
your airplane for a given CG and weight handles spin recovery with a
density altitude of 3K, it will most definite be far less forgiving with a
density altitude of 12K. Think about it, if you put an airspeed indicator
on the rudder measuring the rotational speed lets say it would normalize
at 20 knots (????). It would normalize at 20 knots with a density altitude
of 1K or 25K, its just at 25K you would be spinning like a pinwheel (much
faster RPM)! Add to equation that the rudder to stop the spin is airspeed
dependent as well and you should get the idea. If you added a more aft CG,
and more weight so the rotational inertia is greater you may very well
have a airplane that is in an unrecoverable spin.
You don't have to go to extremes, go on a trip and push weight to limit,
have CG pretty aft, and land at a high elevation airport, or even a lower
elevation airport but it is hot and humid and you have an airplane that
you may not know as intimate as you may think.
I spoke to a P-51 (the hot I think it was the G model) WW2 test pilot and
he spoke of his 2 weeks of testing by the book. His commander let him take
it up to fool around with after he did such a good job, but warned to not
break it. He rocketed up to ~ 20K to meet up with 2 other friends and
figured he would loop and meet them upside down. Horror set in when he was
going to meet nose to nose with him being upside down. He pulled on the
stick, stalled and entered a spin so fast he could not believe it. He did
many a spin, never that high. Spin was unrecoverable, he said he was
spinning so fast it was amazing. He decided at 8K to jump. He opened
canopy and unbuckled and when he stood on seat to get out plane, it began
to fly, so he got back in. His buddy was following him down and he was so
dizzy and disoriented he could not fly the plane. His buddy followed him
and told him what to do with controls for 20 or so minutes and he was then
able to land safely.
I am not mentioning this to scare anyone, just to bring awareness so you
are more confident to know how your plane might react configured in
conditions you never experienced before.
After Europa building often I go flying my model at night at the Local
High School. Often will get in many dozens of spins from high altitudes.
Sometimes the model for a given CG and weight would not even enter a spin,
sometimes it would just be wanting to spin and if you entered would be
unrecoverable and would make a hole in the ground. Elevation of field is
bout 80MSL. It was the thickness of air, hot and humid makes spin entry
very easy, cold and dry far harder. After learning plane and understanding
what was going on, I can adjust CG to make it perform as I want.
Ron Parigoris
Andy mentioned in a letter I saw some time ago that if you fly above 1370
up to 1450, limit CG less aft by 1" and less forward by 1". Probably not a
bad idea, but if you are at aft CG for 1370 and flying at 1525 you better
be on your best behavior. If you are flying into Denver at 1525 and 1370
aft CG when it is very hot and humid, better best your best behavior. Not
much different than flying a tailwheel sometimes, strong gusty cross from
right on hard runway comes to mind, if you don't let things get out of
hand things work out nicely. For those that things worked out nicely for,
I am sure they knew what they were in for, and compensated. Of course you
could try and avoid undesirable things as hard as you can, but be prepared
in case you must deal with.
Checked by AVG.
19:23
|