Nimbus 4DT accident 31 July 2000 in Spain.

Good comments, Don.

If the break occurs between the winch and drogue the 'chute will collapse
and pass harmlessly below the glider, releasing automatically from the
glider in most cases.

If the break is between the glider and drogue, (weak link failure) then the
drogue will be open as long as the winch driver maintains power. In this
case, the winch driver is the key. My driving technique is to cut the
throttle and let the drogue collapse and drop to the ground. Comments?

The worst case that is very rarely seen is that somehow the glider gets in
front of the drogue and it overtakes the glider from behind. This is the
equivalent of getting an air tow rope entangled with the glider. Both are
equally rare. This is why once the drogue is on the ground, the winch
driver must not move the cable until he hears that it is safe to do so.

It is very important to point out that almost all the cable breaks were
using the old steel wire. The new Dyneema winch cables rarely break. The
last I heard, Aero Club Landau in Germany had more than 4000 launches on
their 'plastic' cable without a single break. ACL is also getting more than
1200 meters AGL with their winch launches.

Bill Daniels

The pilot is trained not to land on the wire if at all possible.
"Don Johnstone" wrote in
message ...
Just to add to what Bill has said, the really low launch
failure 100 is one of the minor problem areas. If
the launch is flown correctly it can be quite safely
handled. The good point is, as Bill has pointed out
that there is a large amount of airfield still in front
of you. The bad news is that by the time the nose has
been lowered the airspeed may be below the minimum
allowed for the deployment of airbrakes. It may not
be possible to lower the nose any further to increase
the speed because of the proximity to the ground and
therefore a touchdown has to be achieved without using
airbrake. Patience is required as most modern gliders
float a long way even at 50 kts in ground effect. (Grob
103 will travel the length of the 10000ft runway at
Marham from 20ft/60kts) Simulating a launch failure
at this height is not recomended as there is a real
danger that the drogue will inflate as the winch driver
cuts the power and drape itself over the cockpit. The
good news is that such breaks are rare as the strain
on the cable is reducing before increasing again. The
procedure can be simulated by carrying out a faster
than normal approach, pulling up and closing the airbrakes
and then recovering from that situation which puts
the glider in the same situation as a low break but
without the cable in the way.


At 04:30 28 June 2005, Bill Daniels wrote:

'Kilo Charlie' wrote in message
news:9D3we.3579$Qo.3471@fed1read01...
Your input re winch launches is appreciated Bill....esp
for those of us
that
have never done one!

Please don't take this as a criticism of winch launches
but through this
thread there has not been any mention of what happens
at the critical low
level altitude when the cable breaks. There is clearly
also a zone of
real
problems with aerotows too.....esp here in the desert
with few, if any
landing options straight ahead. What do you guys
teach re breaks at 100
feet? It seems like landing ahead would be good but
how much altitude
does
it take to regain the necessary speed to be able to
control the glider for
landing when at a high angle of attack? Sorry if
this is too obvious for
those of you that do it all the time!

Casey


Thanks, Casey.

The climb profile must be such that a safe recovery
with generous margins be
possible from any height that a cable break occurs.
Safety is the product
of airspeed, altitude and attitude - and good training.

If the break happens at 100 feet, then 90%+ of the
runway lies ahead to
receive the glider. At 100 feet, the glider will have
full climb airspeed,
approx. 60 knots, but then pitch attitude will only
be 20 - 30 degrees. A
prompt, gentle pushover to a glide at approach airspeed
is all that is
needed to land straight ahead.

If the break occurs higher, say 300 - 400 feet, then
the straight ahead
landing is still possible with spoilers but a tight
360 pattern is also
possible. The two options overlap by a good amount
of height depending on
the airfield. At this height, the climb attitude will
be about 45 degrees
nose up (although from the cockpit it will feel like
60 degrees) so a more
aggressive pushover is needed.

All these situations will be practiced over and over
until the instructor
feels the student reacts instinctively and correctly
to each. The student
must firmly push the nose down until the airspeed is
observed to be at a
safe value and increasing before establishing a glide
for a straight ahead
landing or a turn for an abbreviated pattern.

I must admit that winch launch LOOKS scary and FEELS
scary to the
uninitiated but the procedures worked out over literally
tens of millions of
launches in Europe and elsewhere make it actually safer
than air tow.

As for releasing over the winch instead of wherever
the tow plane takes you,
I see by looking at a lot of On-Line Contest IGC files,
that most air tow
releases happen within a mile of the takeoff point
and the glider is rarely
in a thermal at release but must glide around looking
for one just like with
a winch launch. If you don't find a thermal, a winch
re-light will cost you
less than $10.

The latest European winches are getting even heavy
gliders to over 1000
meters AGL so finding lift shouldn't be a problem.

Bill Daniels

F.L. Whiteley writes
I was first introduced to the push-over at altitude while being checked
out for winch launch at RAF Bicester. It's a useful exercise for
experiencing the amount of push over required and to see the amount of
dirt and dust that might float up from the floor. It can be alarming
the first time and ignored subsequently.

On a slightly light-hearted note, I consider the chance to throw all the
dust and junk that accumulates on the cockpit floor up the nose of the
instructor behind me to be a petty but quite fitting vengeance for his
having pulled the plug on a perfectly good launch in the first case for
the sake of drill

--
Bill Gribble
http://www.scapegoatsanon.demon.co.uk
- Learn from the mistakes of others.
- You won't live long enough to make all of them yourself.

F.L. Whiteley wrote:

Statement: "You have control"
Response: "I have control"

I have known of an instructor and tow pilot flying together where no one was
in control and the glider exceeded VNe slightly in a dive and was recovered
gently once the situation was realized. It could have ended otherwise.

The instructors of my club were pretty hardcore with that "my controls /
your controls" thing. I would never have thought somebody would not do
so... until:

Until I got my introduction into mountain soaring. Not a club thing, so
the instructors were unknown to me. Once during a flight, the instructor
demonstrated something, I forgot what. Anyway, after the demonstration,
we flew along gently and quietly. After a while, he made a shallow turn
away from the mountain into the valley. "What is he doing?" I asked
myself, waiting for his explanation. He didn't explain anything, but
after a while, he suddenly asked: Why are you flying over the valley?
Turned out, neither of us had the controls, both thinking the other was
flying. So much for a well trimmed glider.

I've learnt that lesson.

Stefan

LMAO now. Thanks!

Have they changed that much? My ideas were trained into by BGA
instructors in the late 1970s.

Alas, but this discussion wasn't about winch launching. My fault for
letting it descend into something in which I have very limited
experience, and apparently with earlier generation equipment.

What I was responding to was this notion of how a glider might be spun
with coordinated controls during a winch cable break recovery. So let's
get back to that. In another thread.

Hi,

actually, it was the emphasis on this and noticing my instructor making
discrete requests of the ground crew to go find ballast that led me to
guessing what it was he had up his sleeve when that time came!

One fellow student made the mistake of telling the instructor that he had
smelled the exercise coming and that it thus was no surprise. He got the
signature in the little leaflet that we use to record training progress...

....and another simulated cable-break without any warning at the very next
launch. Still a perfectly good recovery.

Ciao, MM
--
Marian Aldenhövel, Rosenhain 23, 53123 Bonn. +49 228 624013.
http://www.marian-aldenhoevel.de
"What did you expect to see out of a Torquay hotel bedroom window? Sydney
Opera House perhaps? The Hanging Gardens of Babylon? Herds of wildebeest
sweeping majestically across the prairie!" Basil Fawlty

Marian Aldenhövel wrote:
Hi,

Training for wire breaks starts at a high altitude in free flight. The
zooms, simulated break at 60 knots and pushover are repeated many times
until the student performs them instinctively.


Interestingly we don't do it like this where I am learning to fly.

We are taught to plan every launch as featuring a wire break and to
preplan up to what altitudes to land straight, turn back or fly the
pattern as part of the takeoff-check. During training we are to say
these altitudes and actions out loud.

Before soloing we do a minimum of three excercises where the instructor
pulls the knob at some point during the launch. So it's the real thing,
nothing "emergency-like" there. We do not train wire-breaks at altitude.

Still I feel very safe. And I also found pushing over, gaining normal speed
and then attitude the natural thing to do. It helps to have a plan as to
what to do next but up to there it really is instinct. I have not heard
of any of my fellow-students _not_ reacting that way.

it Ciao, MM
It comes down to flying the glider.

Winch launches are normal practice, and recovery from launch failures are part
of our normal training. So apply the normal rules.

We teach / have been taught a simple truth - nothing you do is going to improve
matters before you have a safe flying speed. If there is a launch failure, you
have to retain or regain safe flying speed and attitude first.

It does not matter in what part of the flight regime you are in, if you find
yourself below stall speed, you soon find you are not flying. When close to the
ground this can have unpleasant consequences. So we learn to always have enough
energy to regain a safe speed,attitude and height should a cable fail. This
means no "rocket" launches, but rather a smooth progression into the steep
climb, at a safe speed. If the cable then breaks, it is simply a matter of
smoothly but decisively moving the stick forward (no aerobatic bunting required)
and a little patience till the airspeed recovers. Again, there is no point in
getting ahead of things here, once the glider is flying at a normal attitude and
speed is the time to assess your choices. YOu should have planned what your
alternatives would be before the launch, so this should be a time to confirm and
act on them. But you are flying a normal aircraft in a normal way. The only
thing unusual will be how far you are down the runway, and this is dependant on
how high the failure occurred. If you are really low, you land ahead, there is
lots of runway. If there is lots of runway behind you, you should have lots of
height to make a circuit.

There is one field where I fly, where you have to be careful of energy,
launching uphill, with a heavy two seater on a shortish cable, there is an
uncomfortable part of the launch where you have few safe options. But this is
not a usual winch situation and still a lot safer than trying the same thing
behind a tug...

Bad situations, as always come from a sequence of bad choices, or events, and
you can usually avoid them.

As an example:
From personal experience, it can be somewhat unnerving to find yourself having
to keep the stick forward when there is an awful expanse of brown stuff filling
the canopy.
How did I get there - low wing loading trainer, 10kt on the nose and an over
enthusiastic winch driver had me at the upper end of the safe winch speed window
at 20", so I rotated into the steep climb to control the speed. At 60" going
through the wind gradient now, and the winch driver is still poaring on the
power when the weak link goes.
Training and experience take over even for a low time pilot, and I push over
smoothly, (I will admit to lifting the dust... ) Then it is a case of wait ,
seemingly for ever until the speed is back. Nose is well down at this point, but
you are not worried about the outside at this point - only with flying
percisely, and getting the speed back in the green arc. Then a smooth transition
to normal attitude, pop the brakes and the shortest flight of my career is over.

Should have released when I felt the excess power
Should have accepted overspeed rather than pulling so hard to slow the winch
Should have had better situational awareness and realised I was getting into a
dangerous corner

Lots of "should haves", but the point is that because of having enough speed,
even a cable break at very low height in the steep climb was recoverable.
Despite having less than 20kt on the ASI at the top of the push over, the low G
meant the aircraft was still flying. Of course, coarse control movements will
get you into trouble here, but then they aren't advisable any other time either.


For what it is worth - before we fixed our drum, we had such frequent cable
breaks that my instructors were confident of my ability to handle one - I had 9
real failures before going solo...

These days we have to simulate them.
--
Bruce Greeff
Std Cirrus #57
I'm no-T at the address above.

Mark Wright wrote in message ...
At 14:24 28 June 2005, F.L. Whiteley wrote:

At my club we do something similar with winch launch
radio signals during
the launch process. Nothing else is accepted.

'Up slack, up slack, up slack'
'Go, go, go'
'Stop, stop, stop'

Forgive me but this must sound like Yogi Bear conducting
the launch ! In the U.K. we have the following system
to help avoid confusion of a mishear

Take up slack ( Three words )
All Out ( Two words )
Stop ( One word )

To get rid of radio failures, bad transmission, confusion or mishear
etc. etc.
We in the Netherlands generaly do not use radio's at all. We use a
bright light: flashing (take up slack) full (all out), out (stop!) for
any other communication with the winch we use radio if neccesary.
Sometimes a large white board (diameter 1 meter) in a pole is used: up
(take up slak), down (all out), waving left to right, right to left
(stop!!)

If the winch has the sun in the back then sometimes the withe board is
difficult to see but a bright light (from a car for instance) is
always vissible.

Diederik

On Tue, 28 Jun 2005 08:54:18 -0600, "Bill Daniels"
wrote:

It is very important to point out that almost all the cable breaks were
using the old steel wire. The new Dyneema winch cables rarely break. The
last I heard, Aero Club Landau in Germany had more than 4000 launches on
their 'plastic' cable without a single break. ACL is also getting more than
1200 meters AGL with their winch launches.

Flying on the same airfield as the Landau Aero Club, I'd like to add a
few comments:
- There have been lots of cable breaks with Dyneema ropes now (also of
other Dyneema cable users - these plastic cables are used by many
clubs in Germany now). At the moment my club is not sure if the
Dyneema cable is really cheaper to operate than steel cable on the
long run.
- The number of flights that reached more than 1.000 meters can be
counted on one hand, and required to place glider and winch in areas
that were far away from any runway...





Bye
Andreas

41 years ago I joined the Vultures club in Michigan, a winch only club
where I learned to fly gliders and soar.

Off topic I know - but I was on a short visit to the US just recently and spent
a very enjoyable day with the Vultures. It was interesting to compare their
setup to our own club in the UK.

Chris