Head orientation in turns--how is it taught for aviation?

On 2007-06-11 12:39:10 -0400, "Maxwell" said:


"Dudley Henriques" wrote in message
news:2007061101084716807-dhenriques@rcncom...

Bertie is correct. Barrel Rolls are perhaps the most misquoted and
misunderstood maneuver done in an airplane.
Basically, you can do a barrel roll as loosely or as tight as the
airplane's flight envelope will allow. You can also enter a BR from many
different flight conditions involving many different g loadings.
The main thing to remember about barrel rolls is that they are a 3
dimensional maneuver through 3 dimensional space and that the common
denominator in a barrel roll regardless of the g used is that it will
remain POSITIVE all the way around. The one exception to this would be
after the pull and roll application, you can unload the airplane over the
top and drop the g to +1 if you like to loosen the roll rate, but that g
must be regained during the recovery.
Basically, you will be somewhere over +1g in the entry as you raise the
nose, then at some positive +g throughout the roll ranging from as
unloaded as you want to loosen up the airplane or as high a positive g and
tight a roll as the envelope will allow. As long as the airplane
transverses 3 dimensions through the roll, it's a barrel roll.
I've done them as loose as a 90 degree change of direction at the top apex
in a P51,the F8F, and several jets including the T38, and as tight as a
corkscrew in a Pitts S1Sl which was highly loaded with +g and extremely
tight.
Bob Hoover's rather famous Iced tea stunt in the Shrike is probably
responsible for much of the misconception about barrel rolls. He does them
fairly loose and with just enough positive g on the airplane to keep the
glass from spilling without stressing the airplane. The "secret" to Bob's
tea trick is simply his smoothness through the roll as much as keeping
positive g on the tea. It's really this smoothness that makes this stunt
possible, as although positive g will keep the tea inside the glass. (You
can actually POUR tea as you're rolling the airplane but ONLY if you're
as smooth as Hoover :-)
The reason smoothness is so necessary for the tea trick is that even
though you might have positive g on the airplane and in effect doing a
barrel roll, if you are not perfectly coordinated through the roll (any
excessive yaw for example) your tea will slide off the glare shield
laterally and you don't want that......not if you're Bob Hoover anyway :-)
So it's positive g for the roll, and smoothness and perfect coordination
for the tea stunt.

I'm not talking about Bob's tea trick. Obvoiusly, positive Gs and
coordination is the key there. And I'm not sure I understand or agree with
your post. But I think it might be possible we having a terminology issue
here with the definition of a barrel roll.

I fully admit barrel rolls as defined by most pilots require more than
"exactly 1g", and usually a little negative, depending on the desired flight
path. Also, doing a near 1g roll as I mentioned, more than 1g will be
required to set up the manuver, and return to level flight afterwards. But I
disagree that it one needs to deviate much from 1g to roll the wings of an
aircraft 360 degrees if flying an arc. Depending on the arc and corkscrew of
your flight path, you can roll with very little if not no stress on the
aircraft.

No. Barrel rolls do NOT go negative generally. If you went negative you
would change the roll arc and destroy the roll. You can unload to 0 g
through the top however without destroying the roll arc, but if you do,
you have to reapply positive g almost immediately as you pass through
inverted to regain the roll arc. As I said, you can do a barrel roll
at any positive g; as tight or as little as the flight envelope for
the aircraft will allow up to 90 degrees of flight path direction
change at the roll apex.
Generally the roll profile will be the application of positive g above
+1 from the roll initiation (either from level flight or from a slight
dive offset to gain energy if needed) followed by coordinated roll and
back pressure into the roll arc maintaining positive g with varying
back pressure to maintain the roll arc through the roll and through the
recovery back to the entry heading.
You can NOT at any time during a barrel roll, allow the g to go
negative as doing so will instantly destroy the arc of the roll.
Dudley Henriques

Erik writes:

How the hell would you know?

Because I took training in motorcycle riding, and I've driven motorcycles in
the past. Bicycles work on the same principle. And so, apparently, do
aircraft.

Nomen Nescio writes:

By already being in a climb at "one altitude" and maintaining it through
"another".

At some point your vertical speed must change, and then your net acceleration
will change as well.

Wrong!
It's not!

It is constant for all practical purposes.

If one G is defined as 32.2 ft/sec/sec, it can be done. I'll leave it to
you to figure out how.

It cannot be done, and you cannot demonstrate otherwise.

In rec.aviation.piloting Mxsmanic wrote:
Erik writes:

How the hell would you know?

Because I took training in motorcycle riding, and I've driven motorcycles in
the past. Bicycles work on the same principle. And so, apparently, do
aircraft.

Let's see, airplanes free to move in 3 axis, orientation and velocity
determined by gravity, engine thrust, and aerodynamic forces on the
control surfaces.

Motorcycles, free to move in 2 axis, orientation and velocity determined
by gravity, engine power, coefficient of friction between the tires
and the surface, the surface itself, relative angle between front
and rear wheels, gyroscopic action of the wheels.

Yep, you're right, they're identical.


--
Jim Pennino

Remove .spam.sux to reply.

Tell you what. Sit at your sim, do things with the joystick, including
a roll.

What do YOU feel? I g straight down.

As it happens, rolls can be done the same way, but you don't have the
analytical skills to demonstrate that to yourself on paper, and for
sure are never going to experience it in real life.

On Jun 11, 4:13 pm, Mxsmanic wrote:
Nomen Nescio writes:
By already being in a climb at "one altitude" and maintaining it through
"another".

At some point your vertical speed must change, and then your net acceleration
will change as well.

Wrong!
It's not!

It is constant for all practical purposes.

If one G is defined as 32.2 ft/sec/sec, it can be done. I'll leave it to
you to figure out how.

It cannot be done, and you cannot demonstrate otherwise.

On Jun 12, 1:53 am, "ManhattanMan" wrote:
Bertie the Bunyip wrote:

I think he probably tried Viagra, but found it only made him taller.

Boom! Head shot!

Or straight over the top :-)
You are awarded the kooks tail and both ears

writes:

Let's see, airplanes free to move in 3 axis, orientation and velocity
determined by gravity, engine thrust, and aerodynamic forces on the
control surfaces.

In a coordinated turn, aircraft move in two dimensions, not three. They roll
into turns to keep the acceleration vector parallel to the yaw axis.

Motorcycles, free to move in 2 axis, orientation and velocity determined
by gravity, engine power, coefficient of friction between the tires
and the surface, the surface itself, relative angle between front
and rear wheels, gyroscopic action of the wheels.

In a coordinated turn, motorcycles move in two dimensions. They lean into
turns to keep the acceleration vector aligned with the center of gravity and
the plane of the rear wheel.

Yep, you're right, they're identical.

Pretty much, in this context.

Erik writes:

3) Meet me in real life, I'll beat the living daylights out of
you just to make me feel better. Yep, violent, but who gives
a ****?

District attorneys do. You've established premeditation, for one thing. It's
a really bad idea to threaten people in writing, especially in written forms
that will be archived indefinitely and exposed to public view. It can work
against you in ways you may not at all suspect.

Mxsmanic wrote:
Erik writes:


3) Meet me in real life, I'll beat the living daylights out of
you just to make me feel better. Yep, violent, but who gives
a ****?


District attorneys do. You've established premeditation, for one thing. It's
a really bad idea to threaten people in writing, especially in written forms
that will be archived indefinitely and exposed to public view. It can work
against you in ways you may not at all suspect.

Yep. I'll be suspect number one if I ever fly into france and
you happen to disappear.

Mxsmanic wrote:

writes:


Let's see, airplanes free to move in 3 axis, orientation and velocity
determined by gravity, engine thrust, and aerodynamic forces on the
control surfaces.


In a coordinated turn, aircraft move in two dimensions, not three. They roll
into turns to keep the acceleration vector parallel to the yaw axis.

Hey, asshole, airplanes move in three dimensions period.

Motorcycles, free to move in 2 axis, orientation and velocity determined
by gravity, engine power, coefficient of friction between the tires
and the surface, the surface itself, relative angle between front
and rear wheels, gyroscopic action of the wheels.


Yep, you're right, they're identical.


Pretty much, in this context.

And that is why you're an idiot. Or, rather, proof there of, the
why is probably something very old and long surpressed.