Winch Launch Fatality

On Fri, 26 Jun 2009 15:30:05 +0000, Del C wrote:

When I had a flapped Nimbus 2, I always set the flaps to zero for the
ground run and selected the first stage of positive once I was
established in the full climb. That way I could keep my hand on the
release knob during the ground run. The rapid acceleration of a winch
launch gives you almost instant control.

For aerotows I started in full negative and notched the flaps back as I
gained speed and control.

I should have made it clear that was for aero tow: starting the roll in
position 2 (-6 degrees) and going to position 3 (zero) once the ailerons
are fully effective is SOP for an ASW-20 on aero tow.

I flew winch launches entirely in position 3 - zero flap.

Martin


At 14:23 26 June 2009, Martin Gregorie wrote:
On Fri, 26 Jun 2009 13:15:04 +0000, Big Wings wrote:

Flapped gliders where the setting needs to be changed from negative
during the ground run are an interesting case. Starting (aerotow)
launches in negative reduces the probability of a wing drop, but
one's
hand is in the wrong place to react if it does. What is the best
option
for those guys?

Good question.

When I had an ASW-20 I kept my hand on the release until the ailerons
bit, moved the flap lever to position 3 and put my hand back on the
release with minimum delay. I always assumed this was close to the
optimum, but was that a correct assumption?


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

The SOP for most flapped gliders is to start in full negative, it makes the
ailerons more effective and enables you to plant the tail wheel firmly on
the ground which helps in preventing yaw. It is necessary to ensure that a
non negative setting is selected before the tug leaves the ground because
if it is not the glider is going by road. This tends to be very bumpy and
frightens tug pilots.

For winch launching it presents more of a problem, the ASW17 for example
has a release hook which is more forward than most modern gliders and in
order to get any height it is necessary to move from zero flap, where it
was set for takeoff to a plus setting fairly quickly, in fact as soon as
the glider was off the ground.
I got round the problem of being able to operate the flap and release
quickly by looping para cord around the release knob and round my wrist
making it long enough to ensure that I could not pull the release
inadvertently, and short enough to ensure that I could release before my
elbow hit the rear of the cockpit. I could therefore hold the flap lever
but instantly release if required. The para cord could be stowed at the
top of the launch.

At 17:24 26 June 2009, Martin Gregorie wrote:
On Fri, 26 Jun 2009 15:30:05 +0000, Del C wrote:

When I had a flapped Nimbus 2, I always set the flaps to zero for the
ground run and selected the first stage of positive once I was
established in the full climb. That way I could keep my hand on the
release knob during the ground run. The rapid acceleration of a winch
launch gives you almost instant control.

For aerotows I started in full negative and notched the flaps back as
I
gained speed and control.

I should have made it clear that was for aero tow: starting the roll in
position 2 (-6 degrees) and going to position 3 (zero) once the ailerons

are fully effective is SOP for an ASW-20 on aero tow.

I flew winch launches entirely in position 3 - zero flap.

Martin


At 14:23 26 June 2009, Martin Gregorie wrote:
On Fri, 26 Jun 2009 13:15:04 +0000, Big Wings wrote:

Flapped gliders where the setting needs to be changed from negative
during the ground run are an interesting case. Starting (aerotow)
launches in negative reduces the probability of a wing drop, but
one's
hand is in the wrong place to react if it does. What is the best
option
for those guys?

Good question.

When I had an ASW-20 I kept my hand on the release until the ailerons
bit, moved the flap lever to position 3 and put my hand back on the
release with minimum delay. I always assumed this was close to the
optimum, but was that a correct assumption?


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |