Glider accident while filming commercial in 2011. NTSB Report updated

If Bill D could be bothered to read my posting before spouting a reply he
wouls see that I had started the launch with full forward stick in both
cases.
Hard acceration with these gliders can cause the tail to hit the ground
hard - not safe. To avoid this the tail of the K8s are usually held down
for the launch. Too hard acceration can cause the glider to shoot into the
air and immediately into a 45 degree climb despite the stick position. If
the rope breaks at this point you have too little height to recover. Hence
the winch driver will give slower initial acceleration with these types.
By regained control I mean the elevator having any effect. Until then you
are just a passenger.
I was always taught with ground launch to keep it straight and level until
the glider lifts off in a shallow climb. When a safe speed had been reached
to rotate steadily into a full climb. At any point in this process you can
still recover and land safely using the correct procedures - as taught be
both the german and british systems.


At 14:42 29 June 2013, Bill D wrote:
On Saturday, June 29, 2013 8:22:46 AM UTC-6, Nigel Pocock wrote:
Excessive initial ecceleration can cause problems with certain types. I
=20
have experienced it with 2 types.=20
=20
PW5 with stick fully forward at the start of the launch. Hard
acceleratio=
n
=20
caused the glider to rotate from the nose wheel to the tail wheel and
=20
rocket into the air. I only managed to regain control at about 50ft.
=20
The other one is the K8. Light glider, high wing. Similar problem.
=20
=20
=20
If slow acceleration is a safety problem what about the ground run and
ta=
ke
=20
off with aerotow using belly hooks, and autotows?

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

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

On Saturday, June 29, 2013 8:22:46 AM UTC-6, Nigel Pocock wrote:
Excessive initial ecceleration can cause problems with certain types. I

have experienced it with 2 types.

PW5 with stick fully forward at the start of the launch. Hard acceleration

caused the glider to rotate from the nose wheel to the tail wheel and

rocket into the air. I only managed to regain control at about 50ft.

The other one is the K8. Light glider, high wing. Similar problem.



If slow acceleration is a safety problem what about the ground run and take

off with aerotow using belly hooks, and autotows?

Here's a PW-5 winch launch done right. Note the 1 second ground roll.
http://www.youtube.com/watch?v=IseFvZXK7Dw

Here's a K8 also with a one second ground roll.
http://www.youtube.com/watch?v=ict8W0Q5ZpA

Both of these launches were at accelerations greater than 1G. Neither showed an "uncommanded" pitch up. So, neither the gliders nor the acceleration are a problem.

Thanks for the info Andreas.

Not that the reporting is that diligent in either case when far from home.
And BGA Numbers include any that occurred to a BGA member, anywhere, in
any registration.

Bruce

On 2013/06/29 2:23 PM, Andreas Maurer wrote:
On Fri, 28 Jun 2013 09:56:50 +0200, BruceGreeff
wrote:

Indeed.

As an example - the BGA statistics include any accident or incident
reported by a member anywhere in the world. So their numbers include
locations in Spain and South Africa.

The German numbers do not.

I express no opinion on which is a better approach. Merely that the one
is organisational statistics and the other is geographic.

HI Bruce,

German accident statistics include any accident/incident that happened
on a German airfield, in Germany, or in which a German registered
aircraft was involved, worldwide.


Cheers
Andreas


--
Bruce Greeff
T59D #1771