Teaching the aerotow

[Paul Moggach]

I'm sorry, but I'm with the others that simply delay
teaching the aerotow until the students have a firm
idea of how to turn the aircraft using co-ordinated
use of the stick and rudder, and know how to judge
that the aircraft is in straight and level flight.
Any early notion that you turn or control the direction
of the aircraft with the use of rudder alone is just
not right and will plant the seeds for the stall/spin
scenario later. Also it is important for the first
6-8 flights that the student not have their hand on
the stick during the takeoff and landing. During the
initial and final phases of flight the aircraft requires
large movements on the controls. A high per centage
of students that are are exposed to these movements
early in their flight training become 'stick mixers'
on aerotow. On the other hand, once you stop introducing
the aerotow too soon (they can follow through on the
controls once you are through lower level turbulence),
you see the 'stick mixing' virtually disappear and
you get better aerotowing skills out of a wider range
of your student populations. Further they don't seem
to take any longer in terms of total flights, to learn
the aertow.

Both the phenomena noted above are good examples that
our students learn both what we intend and what we
don't intend if we are not careful, and how powerful
the law of primacy is. What appears to be easy in
the beginning is not always the right thing to do.

Paul Moggach (4,000 flights in the back seat)
Paul Moggach

[Terry]

Any early notion that you turn or control the direction
of the aircraft with the use of rudder alone is just
not right and will plant the seeds for the stall/spin
scenario later. Also it is important for the first
6-8 flights that the student not have their hand on
the stick during the takeoff and landing.
================================================== ==============

I did not write that nor have I advocated "turning ... with the use of
rudder alone." The object of formation flight is to maintain relative
position. Coordinated flight should be accomplished, but not at loss
of position. A coordinated turn with a bank angle greater or less
relative to that of the tow plane will result in becoming out of
position. Primacy for coordination would have the student looking to
the yaw string when they should be looking through the tow plane at the
horizon. Like Burt said, watching the trend.

In showing what the rudder can accomplish, I am contributing to
coordinated flight off tow. When your students perfom "boxing the
wake" how do they maintain the corners while coordinated? I usually
ask for a two count at each corner to prove it is not an accident and I
do not think I could maintain that position in any other manner than by
rudder with bank matched to the tow plane's level wings.

I don't understand you reluctance to allow your students to fly.

Respectfully,
Terry

[Eric Greenwell]

Paul Moggach wrote:

> Any early notion that you turn or control the direction
> of the aircraft with the use of rudder alone is just
> not right and will plant the seeds for the stall/spin
> scenario later.

Actually, I had problems getting students to steer with rudder.

A few students had a difficult time "uncoordinating" so they could
properly control the glider while on the ground. As the glider slowed
down during the landing roll and the wing tip started down, they would
use the ailerons to level the glider (no problem) AND the rudder (big
problem as we'd go shooting off the runway) to "coordinate" with the
ailerons.

Only a couple students had this problem in excess, but it made me
rethink the concept of "coordination". I decided the important thing was
to make what you saw outside the glider look right:

* controlling the bank angle with the ailerons
* controlling the pitch angle with the elevator
* controlling the yaw with the rudder

I stressed "getting the view out the window" correct by using the
appropriate controls. This seemed to make it easier for students to
"coordinate" in free flight, to follow the tow plane as desired (such as
boxing the wake), and to keep the wings level even when steering with
the rudder while rolling on the ground.

Of course, for this method to work, the student has to know what things
should look like during the flight, but that's what we are teaching them
anyway. The difference, perhaps more conceptual than practical, is they
don't have to learn you "coordinate" in flight and you "don't
coordinate" on the ground (and when boxing the wake, and when slipping,
and when spinning, etc). In other words, I think "coordination" is often
over-emphasized, and the student learns to do the right thing in spite
of this emphasis.

> Also it is important for the first
> 6-8 flights that the student not have their hand on
> the stick during the takeoff and landing.

Now, this bothers me. By 8 flights, my students were flying the takeoff
and landing. The takeoff was generally "OK", the landing wasn't pretty,
but little intervention was required to make it safe for the pilots and
plane. They were no where near ready for solo, of course, or for
anything but easy weather conditions, but they knew what things should
look like out the window in front of them.

> During the
> initial and final phases of flight the aircraft requires
> large movements on the controls. A high per centage
> of students that are are exposed to these movements
> early in their flight training become 'stick mixers'
> on aerotow.

All students seemed to do this at first, even though they had not been
exposed to the initial and final phases of flight. I'd just tell them to
hold the controls steady, and when they saw the glider settle down and
tow by itself, it usually didn't happen again. Another effective
demonstration was to wiggle the controls around rapidly as they do, and
to show them how the glider can't possibly react that quickly. No more
stick mixers after those demonstrations.

--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

[Robert Ehrlich]

Eric Greenwell wrote:
> ...
> Only a couple students had this problem in excess, but it made me
> rethink the concept of "coordination". I decided the important thing was
> to make what you saw outside the glider look right:
>
> * controlling the bank angle with the ailerons
> * controlling the pitch angle with the elevator
> * controlling the yaw with the rudder
>
> I stressed "getting the view out the window" correct by using the
> appropriate controls. This seemed to make it easier for students to
> "coordinate" in free flight, to follow the tow plane as desired (such as
> boxing the wake), and to keep the wings level even when steering with
> the rudder while rolling on the ground.
>

I completely agree with this point of view. Thinking about it, any phase
of flight is in some way "coordinated", i.e. involves some simultaneous
action on more than one control in order to fulfill some objective. The
main difference between the "coordination" applied during ground roll
and free flight is in this objective, in the first case keeping the
glider properly lined up and in the second case keeping the flight
symetric. The way students are often taught, i.e. "coordinate" in free
flight and "don't coordinate" on the ground often induces them to do
as if there is no more adverse yaw while on the ground, when the truth
is that this parasite effect often is the most important in this case,
although it may be partially hidden as long as the gliders has 2 points
on the ground (main and nose or tail wheel or skid).

[Stefan]

Robert Ehrlich wrote:

> symetric. The way students are often taught, i.e. "coordinate" in free
> flight and "don't coordinate" on the ground often induces them to do
> as if there is no more adverse yaw while on the ground, when the truth
> is that this parasite effect often is the most important in this case,

I am certainly the scientific and theoretic guy, but it was only when
I've completely stopped to think about those things when my flying
enhanced considerably. The way I do it:

- In free flight, use ailerons to get the desired bank angle, your feet
to keep the string in the middle and the elevator to keep the nose at
the horizon.

- On the ground, use the feet to steer and keep the wings level with the
ailerons.

- On tow, stay in position using all three controls as needed and when
possible try to center the string.

No theory needed. Works for me.

Stefan

[Eric Greenwell]

Stefan wrote:
> Robert Ehrlich wrote:
>
>> symetric. The way students are often taught, i.e. "coordinate" in free
>> flight and "don't coordinate" on the ground often induces them to do
>> as if there is no more adverse yaw while on the ground, when the truth
>> is that this parasite effect often is the most important in this case,
>
>
> I am certainly the scientific and theoretic guy, but it was only when
> I've completely stopped to think about those things when my flying
> enhanced considerably. The way I do it:
>
> - In free flight, use ailerons to get the desired bank angle, your feet
> to keep the string in the middle and the elevator to keep the nose at
> the horizon.
>
> - On the ground, use the feet to steer and keep the wings level with the
> ailerons.
>
> - On tow, stay in position using all three controls as needed and when
> possible try to center the string.
>
> No theory needed. Works for me.

Exactly what I found to be true for my students: make the "picture" (the
view out the front of the canopy look right, and you'll be flying right.

The theoretical reasons for how the glider reacts to control inputs can
be interesting, but you don't need to know them to fly properly. I've
talked to a lot of pilots that know how to fly properly, but don't
understand the theory. The basics of controlling the glider don't
require thinking, but just mechanical reactions to the what the eye sees
(primarily) and what the body feels (secondarily). Thinking is very
important for things that require judgment, of course.

--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA