Keep your hand off the release handle during aero tows!

You're quite correct about the danger close to the ground, however, they're
quite a lot fun when intentionally executed! I watched my partner (and
friend) spin in from about 200 ft (thankfully, he survived). It was after a
ground launch, but entirely unrelated to the launch.


"Del Copeland" wrote in message
...
What ever it is, it will still kill or seriously injure you if do one
close to the ground in a glider. Basically it's a low altitude spin in
with no time or height in which to effect a recovery.

Derek Copeland


At 22:32 12 October 2013, Dan Marotta wrote:
I believe that's what we Yanks call a snap roll.


"Del Copeland" wrote in message
...
At 18:43 12 October 2013, son_of_flubber wrote:
On Friday, October 11, 2013 2:31:00 AM UTC-4, Derek C
wrote:
.... we

were told to start with the stick hard back to contain the
speed.

This led to a number of (usually fatal) flick spin
accidents,...

What is a Flick Spin?

The simulation videos here
http://www.gliding.co.uk/bgainfo/saf...nch-safety.htm
illustrate Flick
Roll and Spin, but no Flick Spin.


Same thing. Due to rapid pitch up caused by the rotational
couple
effect (line of pull below c of g of glider), plus not controlling
the
rate of rotation, causing the wings to stall and a flick roll can
follow. Mostly a problem associated with powerful winches
and
very rapid acceleration.

Derek Copeland

On Thursday, October 10, 2013 4:05:22 AM UTC-6, Terry Walsh wrote:
Fred,



I did not intend this as a comment against Americans I know equally

arrogant people of many different national origins. I was simply commenting

that if this indeed Bill Daniels then he could be considered to be an

expert on winch operations, but his apparent refusal to accept any other

opinion than his own was more than a little arrogant.

I've let the UK "echo chamber" run a bit so they can all congratulate each other for fuzzy thinking.

Arrogant? Indignant and angry are a better words. Every time you screw up, it has enormous impact outside the UK. When those screw-ups are based on institutionalized nonsense, and you try to export that nonsense, it makes me angry. An example is the winch launch section in the 2013 Glider Flying Handbook.

The main source of my guidance isn't from the US, or my own imagination, it's the German SDO Segelflugbetriebsordnung. It contains about the best information on winch launch safety available.

The US stands accused of "doing few winch launches". That's true. Compared to the roughly one million annual launches in Germany, the UK doesn't do many either. That, and their superb safety record, makes Germany a far better source of safety information.

If you want an educational approach, read my thoughts on the acceleration phase and acceleration induced uncommanded rotation.
https://dl.dropboxusercontent.com/u/...celeration.pdf

OK Bill, here is my problem with your argument that all our problems are
basically due to too slow acceleration.

1. I have not seen or experienced these slow acceleration launches and they
are certainly not the norm at any site at which I have flown recently.

2. I have also auto towed (some years ago) where the acceleration is by
definition slow, I never saw a wing drop come close to an accident.

3. The same applies to aerotows, slow acceleration, here I have seen wing
drops and witnessed people releasing but no cartwheels.

4. The reason these wing drops have been fatal is that they occur just
before the glider ls ready to fly. in my mind this implies that the
acceleration was fast since the glider apparently goes from insufficient
aileron control to flying speed too quickly for the pilot to react. I
think perhaps , as Don said that the problem is actually yaw induced roll.

Based on what you say we in the UK have a much worse safety record than the
Germans, so accepting this I agree that we are apparently not getting
something right. I do not agree with your analysis and you have shown no
readiness to accept that there may be another different problem. This is
what I mean by arrogance. If as you say everybody outside UK agrees with
your argument why have none of them posted here to say so.

I think it is a problem caused by individual pilot errors rather than our
procedures. Why I am not sure although I do have some thoughts regarding
pilot currency.

Terry Walsh


At 17:47 13 October 2013, Bill D wrote:
On Thursday, October 10, 2013 4:05:22 AM UTC-6, Terry Walsh wrote:
Fred,
=20
=20
=20
I did not intend this as a comment against Americans I know equally
=20
arrogant people of many different national origins. I was simply
commenti=
ng
=20
that if this indeed Bill Daniels then he could be considered to be an
=20
expert on winch operations, but his apparent refusal to accept any
other
=20
opinion than his own was more than a little arrogant.

I've let the UK "echo chamber" run a bit so they can all congratulate
each
=
other for fuzzy thinking.

Arrogant? Indignant and angry are a better words. Every time you screw
up=
, it has enormous impact outside the UK. When those screw-ups are based
on=
institutionalized nonsense, and you try to export that nonsense, it
makes
=
me angry. An example is the winch launch section in the 2013 Glider
Flying=
Handbook.

The main source of my guidance isn't from the US, or my own imagination,
i=
t's the German SDO Segelflugbetriebsordnung. It contains about the best
inf=
ormation on winch launch safety available.

The US stands accused of "doing few winch launches". That's true.
Compare=
d to the roughly one million annual launches in Germany, the UK doesn't
do
=
many either. That, and their superb safety record, makes Germany a far
bet=
ter source of safety information.

If you want an educational approach, read my thoughts on the acceleration
p=
hase and acceleration induced uncommanded rotation.
https://dl.dropboxusercontent.com/u/...celeration.pdf

Hi Bill,

Did you read Paul Ruskin's analysis of German and UK winch
launching accidents, which was number 66 in this thread. He
concluded that there was no significant difference between fatal
and serious accident rates between the two countries. I note that
Germany had about 4 accidents that came into the stall and flick
roll category while the UK only had one. Germany has about 5
times as many glider pilots as the UK. About 2/3rd's of UK glider
launches are by winch. As Skylaunch has sold many winches to
Germany and Tost to the UK, I assume that the winches are
similar and give the same rates of acceleration in both countries.

BTW, before we had winches at our club, we used to wire launch
by autotow, where the ground run acceleration was REALLY
slow, at least 10 seconds to lift off. I don't remember there
being any ground loop or cartwheel accidents on take off in that
era.

Derek Copeland

At 17:47 13 October 2013, Bill D wrote:
On Thursday, October 10, 2013 4:05:22 AM UTC-6, Terry
Walsh wrote:
Fred,
=20
=20
=20
I did not intend this as a comment against Americans I know
equally
=20
arrogant people of many different national origins. I was
simply
commenti=
ng
=20
that if this indeed Bill Daniels then he could be considered to
be an
=20
expert on winch operations, but his apparent refusal to
accept any other
=20
opinion than his own was more than a little arrogant.

I've let the UK "echo chamber" run a bit so they can all
congratulate each
=
other for fuzzy thinking.

Arrogant? Indignant and angry are a better words. Every
time you screw
up=
, it has enormous impact outside the UK. When those screw-
ups are based
on=
institutionalized nonsense, and you try to export that
nonsense, it makes
=
me angry. An example is the winch launch section in the 2013
Glider
Flying=
Handbook.

The main source of my guidance isn't from the US, or my own
imagination,
i=
t's the German SDO Segelflugbetriebsordnung. It contains
about the best
inf=
ormation on winch launch safety available.

The US stands accused of "doing few winch launches". That's
true.
Compare=
d to the roughly one million annual launches in Germany, the
UK doesn't do
=
many either. That, and their superb safety record, makes
Germany a far
bet=
ter source of safety information.

If you want an educational approach, read my thoughts on the
acceleration
p=
hase and acceleration induced uncommanded rotation.
https://dl.dropboxusercontent.com/u/...Acceleration.p
df

I don't get accident statistics from RAS comments.

The Dropbox link has changed. See:
https://dl.dropboxusercontent.com/u/...celeration.pdf

I can't comment on why your experience is what it is, but the BGA is clearly concerned about "cartwheel" accidents.

Aero tow uses a nose hook so the consequences of a wing drop are much less.

With the glider achieving flying speed in 3 - 4 seconds that's not much to distinguish why earlier or later drop is worse. It's bad whenever it happens.

On Sunday, October 13, 2013 1:35:38 PM UTC-6, Terry Walsh wrote:
OK Bill, here is my problem with your argument that all our problems are

basically due to too slow acceleration.



1. I have not seen or experienced these slow acceleration launches and they

are certainly not the norm at any site at which I have flown recently.



2. I have also auto towed (some years ago) where the acceleration is by

definition slow, I never saw a wing drop come close to an accident.



3. The same applies to aerotows, slow acceleration, here I have seen wing

drops and witnessed people releasing but no cartwheels.



4. The reason these wing drops have been fatal is that they occur just

before the glider ls ready to fly. in my mind this implies that the

acceleration was fast since the glider apparently goes from insufficient

aileron control to flying speed too quickly for the pilot to react. I

think perhaps , as Don said that the problem is actually yaw induced roll.



Based on what you say we in the UK have a much worse safety record than the

Germans, so accepting this I agree that we are apparently not getting

something right. I do not agree with your analysis and you have shown no

readiness to accept that there may be another different problem. This is

what I mean by arrogance. If as you say everybody outside UK agrees with

your argument why have none of them posted here to say so.



I think it is a problem caused by individual pilot errors rather than our

procedures. Why I am not sure although I do have some thoughts regarding

pilot currency.



Terry Walsh





At 17:47 13 October 2013, Bill D wrote:

On Thursday, October 10, 2013 4:05:22 AM UTC-6, Terry Walsh wrote:

Fred,

=20

=20

=20

I did not intend this as a comment against Americans I know equally

=20

arrogant people of many different national origins. I was simply

commenti=

ng

=20

that if this indeed Bill Daniels then he could be considered to be an

=20

expert on winch operations, but his apparent refusal to accept any

other

=20

opinion than his own was more than a little arrogant.



I've let the UK "echo chamber" run a bit so they can all congratulate

each

=

other for fuzzy thinking.



Arrogant? Indignant and angry are a better words. Every time you screw

up=

, it has enormous impact outside the UK. When those screw-ups are based

on=

institutionalized nonsense, and you try to export that nonsense, it

makes

=

me angry. An example is the winch launch section in the 2013 Glider

Flying=

Handbook.



The main source of my guidance isn't from the US, or my own imagination,

i=

t's the German SDO Segelflugbetriebsordnung. It contains about the best

inf=

ormation on winch launch safety available.



The US stands accused of "doing few winch launches". That's true.

Compare=

d to the roughly one million annual launches in Germany, the UK doesn't

do

=

many either. That, and their superb safety record, makes Germany a far

bet=

ter source of safety information.



If you want an educational approach, read my thoughts on the acceleration

p=

hase and acceleration induced uncommanded rotation.

https://dl.dropboxusercontent.com/u/...celeration.pdf

Many earlier gliders in the UK are not fitted with nose hooks, just
belly hooks, but we still don't get any cartwheel accidents on
aerotow. There is a slightly increased risk of tug upsets due to
the glider trying to 'winch launch' after take off if the pilot allows
the glider to get too high (so still a good case for keeping your
hand on the release knob during the early stages of an
aerotow). Likewise wire launching by autotow on the belly hook
did not cause cartwheel accidents, despite the slower ground run
acceleration. The difference with high powered winch launches
is that you are putting in much more energy much more quickly,
so the consequences of a wing drop are much more serious.
What happens is that the wingtip contacts the ground, drags,
causes the glider to yaw, so that the other wing speeds up and
produces more lift, adding roll to the yaw and the glider lifts off
with one wing still on the ground. Then the other wing gets up
into the wind gradient and produces even more lift, and at this
point you are history. The safety message is 'keep your wings
level and pull off immediately if you can't'.

Derek Copeland



At 02:09 14 October 2013, Bill D wrote:
I can't comment on why your experience is what it is, but the
BGA is
clearly concerned about "cartwheel" accidents.

Aero tow uses a nose hook so the consequences of a wing
drop are much less.

With the glider achieving flying speed in 3 - 4 seconds that's
not much to
distinguish why earlier or later drop is worse. It's bad
whenever it
happens.

On Sunday, October 13, 2013 1:35:38 PM UTC-6, Terry Walsh
wrote:
OK Bill, here is my problem with your argument that all our
problems are

basically due to too slow acceleration.



1. I have not seen or experienced these slow acceleration
launches and
they

are certainly not the norm at any site at which I have flown
recently.



2. I have also auto towed (some years ago) where the
acceleration is by

definition slow, I never saw a wing drop come close to an
accident.



3. The same applies to aerotows, slow acceleration, here I
have seen wing

drops and witnessed people releasing but no cartwheels.



4. The reason these wing drops have been fatal is that they
occur just

before the glider ls ready to fly. in my mind this implies that
the

acceleration was fast since the glider apparently goes from
insufficient

aileron control to flying speed too quickly for the pilot to
react. I

think perhaps , as Don said that the problem is actually yaw
induced
roll.



Based on what you say we in the UK have a much worse
safety record than
the

Germans, so accepting this I agree that we are apparently
not getting

something right. I do not agree with your analysis and you
have shown no

readiness to accept that there may be another different
problem. This is

what I mean by arrogance. If as you say everybody outside
UK agrees with

your argument why have none of them posted here to say
so.



I think it is a problem caused by individual pilot errors rather
than our

procedures. Why I am not sure although I do have some
thoughts
regarding

pilot currency.



Terry Walsh





At 17:47 13 October 2013, Bill D wrote:

On Thursday, October 10, 2013 4:05:22 AM UTC-6, Terry
Walsh wrote:

Fred,

=20

=20

=20

I did not intend this as a comment against Americans I
know equally

=20

arrogant people of many different national origins. I was
simply

commenti=

ng

=20

that if this indeed Bill Daniels then he could be
considered to be an

=20

expert on winch operations, but his apparent refusal to
accept any

other

=20

opinion than his own was more than a little arrogant.



I've let the UK "echo chamber" run a bit so they can all
congratulate

each

=

other for fuzzy thinking.



Arrogant? Indignant and angry are a better words. Every
time you screw

up=

, it has enormous impact outside the UK. When those
screw-ups are based

on=

institutionalized nonsense, and you try to export that
nonsense, it

makes

=

me angry. An example is the winch launch section in the
2013 Glider

Flying=

Handbook.



The main source of my guidance isn't from the US, or my
own imagination,


i=

t's the German SDO Segelflugbetriebsordnung. It contains
about the best

inf=

ormation on winch launch safety available.



The US stands accused of "doing few winch launches".
That's true.

Compare=

d to the roughly one million annual launches in Germany,
the UK doesn't

do

=

many either. That, and their superb safety record, makes
Germany a far

bet=

ter source of safety information.



If you want an educational approach, read my thoughts on
the
acceleration

p=

hase and acceleration induced uncommanded rotation.


https://dl.dropboxusercontent.com/u/...Acceleration.p
df

I don't get instructions about how to fly safely from RAS comments.

On 14/10/13 03:03, Bill D wrote:
I don't get accident statistics from RAS comments.

The Dropbox link has changed. See:
https://dl.dropboxusercontent.com/u/...celeration.pdf

On Monday, October 14, 2013 3:03:44 AM UTC+1, Bill D wrote:
I don't get accident statistics from RAS comments.


Which would be an admirable position Bill, except that I took the trouble to go and find the accident reports from the BFU and BGA and posted a list of winch accidents in my comment, including sources and accident report numbers.

The data says that in the period 2006-12 a German pilot had much the same chance as a UK civilian pilot of being killed or injured in a winch accident.

Perhaps you'd let us know whether you now accept that conclusion, rather than claiming that UK winch launches are 10 times more dangerous?


Paul

At 02:03 14 October 2013, Bill D wrote:
I don't get accident statistics from RAS comments.

The Dropbox link has changed. See:
https://dl.dropboxusercontent.com/u/...Acceleration.p
df


Maybe the ancient Gehrlein winches you have in the US are not
powerful enough to cause uncontrollable pitch ups, but we did
have a problem with this when we first had powerful V8 Tost
winches. K8's and the like would rocket up almost vertically
before (usually) the weak link broke. Fortunately none of them
flicked and all the pilots involved were quite switched on and
managed to get the nose down and land safely. The problem
was largely solved by opening the throttle a bit more gently at
the start of the launch. The nice thing about the Skylaunch
winches we have now is that they deliver the right amount of
power for the glider type being launched, so you get the same
ground run time for all types. So one less type conversion issue.

The acceleration induced pitch up effect is only transitory by the
way. During the ground run it is constrained by the tailwheel,
and once the glider is safely established in the full climb the pull
line and the c of g become more closely aligned. The dangerous
bit is the rotation! If the mainwheel lifts off first, the glider
pitches up to a steep angle and then the tailwheel lifts off and no
longer constrains the pitch angle, it is at this point the wings may
stall, and if any yaw is present may flick roll. The safety
message is don't over-accelerate lightweight gliders and control
the rotation rate so that it is not more than 10 degrees per
second.

Derek Copeland