Compare/Contrast: CG hook on aerotow vs. CG hook on winch

On Thu, 31 May 2012 18:05:10 -0700 (PDT), "noel.wade"
wrote:



2) On liftoff - as you get rolling try to use forward-stick and stick-
trim to get the tailwheel off the ground as soon as your rudder is
effective. That'll give you better steering control on the remainder
of takeoff *and* put the wing at a lower angle of attack (so you won't
jump/kite as quickly).

Hi Noel,

I have to admit that I regard this technique as bad airmanship. Really
bad airmanship (for example, an LS-6 will not lift off at all with
that technique).

Let me explain:
I've often seen gliders roll behind the towplane for ages, balancing
on the main wheel, creating lots of rolling drag and bouncing all over
the place with each bump they hit. Usually lots of control deflections
to balance crosswind (a tail wheel in the air doesn't really help to
stabilize against a crosswind...), and often multiple touchdowns after
the first lift off due to PIO.

Sometimes I even see gliders with a pith attitude, effectively
creating negative lift until the pilot decides it's time to lift off.
Scary.


In my opinion it's so much easier to simply lift off with tail and
main wheel at the same time and let the glider float behind the tow
plane - once in the air, any glider is a lot easier to control, and in
my experience on grass strips the acceleration of the tow plane is
significantly better.

I fly from a 2000 ft grass strip where one really can see the
difference in the length of the takeoff run.
It doesn't make a huge difference with a light DG-300, but flying a
fully ballasted open class ship or a Duo Discus the correct technique
(liftoff at minimum speed) is usually the difference between the tow
plane being able to lift off or not (don't ask...).

One additional benefit: If the glider lifts off close to its minimum
speed, control authority of the elevator is less agressive, therefore
it's far less likely to overcontrol the glider and enter a PIO.




Be prepared to add forward stick as you come
off the ground, and don't be shy about changing your trim multiple
times on the takeoff and aerotow.

I'm a little bit puzzled why one should mess with the trim during
aerotow.
By setting the elevator trim to the recommended position for aerotow
before launch (trim forward) you get a slight nose-down stick
pressure on all the (German built) gliders I've flown, which in my
opinion is extremely effective to prevent ballooning: The glider is a
lot more likely to descent behind the tow plane if you don't pay
attention for a moment. Better be too low behind the tow plane than
too high.

In my opinion messing with the trim during aerotow is not a good idea
for an inexperienced pilot - gliders with modern trim systems like the
DG-300 cannot be trimmed nose-down at all (as you have probably
noticed in your 300, it needs a significant stick push which isn't the
best idea if you want to keep your position behind the towplane).

Make one mistake, and you have a neutrally or even nose-up trimmed
glider - one further mistake and you might create brown pants in that
tow plane in front of you that is just disappearing under the nose of
your glider.



3) Throughout the launch and aerotow - USE YOUR FEET!

Indeed. Always. And ignore that yaw string.

But I again
have found many newbies recently that don't think to use their feet on
aerotow.

Clear case of bad training. One needs to learn to actively fly the
glider during an aerotow, otherwise problems are pre-programmed.




Best wishes
Andreas