barrel roll in 172

Unfortunately I do. Most of them are crash films. I believe you can catch a
glimpse of what I'm talking about by viewing Hoof Proudfoot's P38 crash in
the UK. You can find that on Jay Honeck's aviation film page on his site. I
should point out strongly along with this that when viewing the film, you
should realize that the dishout during Hoof's second roll (the one that
killed him) was artifically caused by what both the accident investigation
board and I believe was the intervention with his control yoke by the
kneeboard he was wearing.
Regardless of the cause, dishing out of the second roll was what nailed him.
Dudley Henriques

"Matt Whiting" wrote in message
...
Dudley Henriques wrote:

"Matt Whiting" wrote in message
...

Dudley Henriques wrote:


Scotty McCray flew a Schweizer 2-22 EK for his demonstrations. We
appeared at the same shows many many times and I knew him quite well.
The 2-22 wasn't exactly the "cleanest" glider in the world by today's
standards. Scotty was an absolute master at energy control. His
technique for energy management was in my opinion the best I've ever
seen done in an unpowered aircraft. I think I watched Scotty perform
hundreds of barrel rolls in the 2-22 and never once did I see him dish
it out of a roll.
Strangely enough, it was the addition of horsepower to his aerobatics
that killed him down in Brazil in 73, when the Decathlon he dished out
of a low altitude roll.
One of the nicest and finest guys I knew in aviation.
Dudley Henriques

What does "dished out" mean?

Matt


When you do a roll, the second half of the roll requires changing rudder
and blending stick in elevator and aileron. If you are late on the rudder
change, or late on the elevator blending out from forward elevator to
back elevator, its possible to allow the airplane to change from rolling
on its longitudinal axis to an arc through the back side recovery.
Basically what happens is that you "slide" off the roll axis and widen
the roll nose low through the arc. In effect, you are changing the
aircraft's roll axis from a controlled slow roll to an aileron roll
format, which is primarily aileron and allows the nose to arc naturally
during the roll unlike the slow roll format where the airplane is "flown"
through the entire roll from the roll initiation at the apex of the pull
on the airplane's longitudinal axis.
We call this coming in late and allowing this to happen on the back side
"dishing out" of the roll. Allowing this to happen is one of the major
killers, if not THE major killer of pilots doing low altitude roll
maneuvers.
Not allowing dishout on a roll is so critical in low altitude
demonstration work that when I practiced slow rolls for demonstration
purposes, I would set the airplane on the roll apex at it's inverted nose
attitude while right side up after a pull to the set point from a point
where the altimeter needle was covering the 0 on the altimeter, then roll
the airplane from the initiation point returning the needle to recover
the 0 again as level flight was achieved again on recovery. Any deviation
from that standard was considered a blown roll, and the entire practice
session would have to be re-flown.
Dudley Henriques

I think I got it, but this is a case where a graphic would be worth a
thousand words! :-)

Do you know of any web graphics that illustrate this error?


Matt