Leaving aside the tail hitting the ground aspect, a glider doesn't
necessarily stop accelarating just because it has left the ground
- in fact it is sometimes quite noticeable to me (in a Discus
2cT) that the accelaration is increasing after lift off - especially
with a powerful winch that is capable of acheiving a safe cable
speed of 60+ knots (depending on the type being launched).

Long ago, even with a low powered old winch and far less than
1g acceleration, I remember routinely having to keep the stick
forward in a K8 to prevent over-rotation.

I put my trust in the BGA advice on winch launching which is
based on many decades of experience by dozens of clubs,
thousands of individual pilots and instructors, and with
numerous winch and glider types.

John Galloway


At 15:44 01 July 2013, Bill D wrote:
Nigel, I read your post and it's mostly an "old wives tale".

Yes, gliders lower their tails which can be an issue on hard
surfaces so
so=
meone holds them down as seen in the PW-5 video. On turf,
it's a
non-issue=
.. However, it has nothing to do with acceleration causing
premature
uncomma=
nded rotation. The tailwheel on the ground prevents it.
Glider's don't
"s=
hoot into the air" or do anything else inappropriate under 1G
acceleration.=
It's been thoroughly flight tested.

On Monday, July 1, 2013 8:58:00 AM UTC-6, Nigel Pocock
wrote:
If Bill D could be bothered to read my posting before
spouting a reply he
=20
wouls see that I had started the launch with full forward
stick in both
=20
cases.
=20
Hard acceration with these gliders can cause the tail to hit
the ground
=20
hard - not safe. To avoid this the tail of the K8s are usually
held down
=20
for the launch. Too hard acceration can cause the glider to
shoot into
th=
e
=20
air and immediately into a 45 degree climb despite the stick
position. If
=20
the rope breaks at this point you have too little height to
recover.
Henc=
e
=20
the winch driver will give slower initial acceleration with
these types.
=20
By regained control I mean the elevator having any effect.
Until then you
=20
are just a passenger.
=20
I was always taught with ground launch to keep it straight
and level
unti=
l
=20
the glider lifts off in a shallow climb. When a safe speed
had been
reach=
ed
=20
to rotate steadily into a full climb. At any point in this
process you
ca=
n
=20
still recover and land safely using the correct procedures -
as taught be
=20
both the german and british systems.
=20
=20
=20
=20
=20
At 14:42 29 June 2013, Bill D wrote:
=20
On Saturday, June 29, 2013 8:22:46 AM UTC-6, Nigel
Pocock wrote:
=20
Excessive initial ecceleration can cause problems with
certain types.
=
I
=20
=3D20
=20
have experienced it with 2 types.=3D20
=20
=3D20
=20
PW5 with stick fully forward at the start of the launch.
Hard
=20
acceleratio=3D
=20
n
=20
=3D20
=20
caused the glider to rotate from the nose wheel to the
tail wheel and
=20
=3D20
=20
rocket into the air. I only managed to regain control at
about 50ft.
=20
=3D20
=20
The other one is the K8. Light glider, high wing. Similar
problem.
=20
=3D20
=20
=3D20
=20
=3D20
=20
If slow acceleration is a safety problem what about the
ground run and
=20
ta=3D
=20
ke
=20
=3D20
=20
off with aerotow using belly hooks, and autotows?
=20

=20
K8's and PW-5's, as with all "nose dragger's, are
supposed to rotate
bac=
k
=20
o=3D
=20
nto their tail wheels. What do you mean exactly by
"regained control"?=
=20
=20
Yo=3D
=20
u're still with us so, presumably, it worked. With those
gliders you
=20
shoul=3D
=20
d have started the ground roll with the stick full forward.
=20

=20
Aero tow with a CG hook isn't safe as discussed elsewhere
on this
forum.=
=20
=20
H=3D
=20
owever a tug can't generate the forces a winch can so a
wing drop
induce=
d
=20
g=3D
=20
round loop likely won't be as severe.
=20