Nimbus 4DT accident 31 July 2000 in Spain.

Ian,

I like your train of thought. As well as decoupling from a term that
has such strong connotations.

Ian Johnston wrote:
On Mon, 27 Jun 2005 15:48:07 UTC, Stefan
wrote:

: Last weekend I flew in the mountains. Conditions were rough and I had to
: make fairly dramatic motions of the controls to keep the blue side up.
: I'll log it as an aerobatic flight, then.

All this seems to hinge on what's meant by "aerobatic". Frankly, it
seems like a pretty pointless term to me, since it seems to depend on
the intention of the pilot rather on the manoevres flown. Why, for
example, is a loop aerobatic yet a tight thermalling turn, involving
similar stresses on the glider, is not?

To me, it makes more sense to categorize manoevres as high load / low
load and high risk / low risk, where "load" relates to forces on the
glider and "risk" relates to the speed with which things will go wrong
if the pilot misreacts.

That gives four permutations:

1) low load / low risk (normal flight)
2) low load / high risk (inverted flight)
3) high load / low risk (loop, tight thermalling)
4) high load / high risk (spin or spiral dive recovery)

This is off the top of my head, and I am sure we could argue about the
categories (should there be a "medium" in each case?) and
categorisations (how hard is a loop) for ages.

However, I think I would put many display aerobatic manoevres and
winch launching together in the high load / high risk category: it's
not that winch launching is aerobatic (whatever that means) but it is
also a time when the glider is being flown with higher than normal
structural loadings and when pilot error can cause things to go very
nasty very quickly.

I'd put mountain flying, from the little I have done, in the low load
/ high risk category at the very least, and probably high / high on
rough days.

Ian


--

"Bill Daniels" wrote in message
...
I want to thank Don and Stefan and others from Europe and the UK for
stepping in here.

I am fighting a lonely battle to convince my fellow USA pilots that winch
launch is a perfectly normal way to launch gliders and not some invention
of
the devil.

Bill-

I think that you have a chip on your shoulder re winch launches. I have not
seen a single thread that tries to make winch launches sound like they are
an "invention of the devil". Chris' (OC)point is only pertaining to the
aerodynamics unique to the situation that a glider may be in during a winch
launch cable break. He does not seem to be making any a priori assumptions
that anything is dangerous about winch launching. I think that the
discussion re that unique situation is not only interesting but may also
possibly pertain to some other scenarios such as a hard pull and turn into a
thermal, so would like to have a more detailed understanding of it.

Casey Lenox
KC
Phoenix

On 27 Jun 2005 07:05:00 -0700, wrote:


For pilots who winch launch regularly, the definition of normal flight
attitudes is greatly expanded. But I think you'll all agree that it is
a highly specialized type of flying (even if you are used to it). Pull
on the stick to go faster. Push to go slower. If the cable breaks, no
messing around... stick right forward until the nose is well below the
horizon, then ease it back gently, paying attention to your airspeed.
Abrupt control motions, significantly reduced g, large angles of nose
up and nose down, close to the ground, special considerations regarding
turns... sounds to me like a pretty threatening environment, sort of
like taking off downwind at gross from a short runway. Deserves some
special consideration. And occasional reexamination to prevent the
complacency of experience.

Well...
1. Have you ever flown a model glider without radio control? The one
that you pull up with a rope, simulating a winch launch?
Works like a charm. In *any* halfways correctly trimmed real-size
glider you can let go the stick - and your glider will do the launch
for you. Try that in an aerotow.
How many tow pilots did you say have been victims due to
overcontrolled gliders in the last 50 years?

2. It looks as if you are simply afraid of winch launching due to lack
of training/experience. Having more winch launches than I care to
count, my experience is that *any* student pilot learns winch
launching a lot easier than aerotowing.

3. I had more than enough aerotows where any engine problem of the tow
plane would have led to a bad crash because we were low over an
unlandable area. I prefer by far the winch launch where the complete
airfield is head of me in case of a low cable-break.

4. Recovery from cable-breaks is an extremely straight forward
procedure. Very easy to perform with some training.
What did you say you are doing if you have a rope break in an aerotow
at the end of the runway in 100 ft with unlandable area in front of
you?

5. Sure a winch launch is a highly specialized type of flying. But
isn't flying without any engine at all even more highly specialized?
Imagine that - no engine means that you cannot perform a go-around if
you misjudged your landing approach...

6. Accident statistics definitely prove that winch launching is by far
one of the less risky things you can do if you fly gliders.



Bye
Andreas

wrote in message
oups.com...
For pilots who winch launch regularly, the definition of normal flight
attitudes is greatly expanded. But I think you'll all agree that it is
a highly specialized type of flying (even if you are used to it).

Probably nine out of ten glider launches world wide are by winch. I think
we are the minority using air tow.

Pull on the stick to go faster. Push to go slower.
Wrong. With a tension controlled winch, pull to slow and push to go faster
just like in free flight. If the glider speeds up when you pull, the winch
driver is giving WAY too much throttle.

If the cable breaks, no messing around... stick right forward until the
nose is well below the
horizon, then ease it back gently, paying attention to your airspeed.

No abrupt control inputs are needed. Just lower the nose without undue
delay, insure safe airspeed and land normally

Abrupt control motions, significantly reduced g, large angles of nose
up and nose down, close to the ground, special considerations regarding
turns... sounds to me like a pretty threatening environment, sort of
like taking off downwind at gross from a short runway. Deserves some
special consideration. And occasional reexamination to prevent the
complacency of experience.

OC, you really need to get a modern winch checkout. You have some very
strange and wrongheaded ideas about winch launch.

Bill Daniels

In article ,
says...

In article .com,
says...

...and I returned only to find out that hantavirus had infected each and
every member of the household.

Dude. That is saddest thing I have ever heard.

You poor *******.

In article ,
says...

In article ,
says...

In article .com,
says...

...and I returned only to find out that hantavirus had infected each and
every member of the household.

Dude. That is saddest thing I have ever heard.

You poor *******.

"Kilo Charlie" wrote in message
news:WS%ve.3566$Qo.977@fed1read01...

"Bill Daniels" wrote in message
...
I want to thank Don and Stefan and others from Europe and the UK for
stepping in here.

I am fighting a lonely battle to convince my fellow USA pilots that
winch
launch is a perfectly normal way to launch gliders and not some
invention
of
the devil.

Bill-

I think that you have a chip on your shoulder re winch launches. I have
not
seen a single thread that tries to make winch launches sound like they are
an "invention of the devil". Chris' (OC)point is only pertaining to the
aerodynamics unique to the situation that a glider may be in during a
winch
launch cable break. He does not seem to be making any a priori
assumptions
that anything is dangerous about winch launching. I think that the
discussion re that unique situation is not only interesting but may also
possibly pertain to some other scenarios such as a hard pull and turn into
a
thermal, so would like to have a more detailed understanding of it.

Casey Lenox
KC
Phoenix

Point accepted. Without thinking, I was responding to opinions expressed
elsewhere and not in this forked thread or elsewhere on RAS. My apology to
anyone thus offended.

The situation envisioned in the beginning of this thread is a very
specialized case where a pilot fails to lower the nose below what appears to
be normal glide attitude after a wire break real or simulated and then
attempts a turn with the wing deeply stalled. That this sometimes results
in a spin departure should surprise no one.

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. If this training is done
correctly, the pilot will have no difficulty lowering the nose the right
amount after a cable break.

Experimenting with this can expose some 'interesting' glider behaviors.
Only those gliders with the largest up elevator authority can stop the nose
from falling through at the normal glide attitude once the fall-through
starts - it requires full aft stick. Arresting the fall through in this
manner with very little forward speed results in a deeply stalled wing with
the angle of attack possibly exceeding 45 degrees. Small asymmetric control
inputs will induce a spin departure that resembles a snap roll about the
vertical axis. I am always surprised by the very low G forces - the glider
seems to 'fall' into the spin with great ease. Once in the spin, normal
recovery methods work fine.

Bill Daniels

All this seems to hinge on what's meant by "aerobatic". Frankly, it
seems like a pretty pointless term to me, since it seems to depend on
the intention of the pilot rather on the manoevres flown.

In the U.S., it (aerobatic definition - bank greater than 60 degrees,
pitch greater than +/- 30 degrees) determines whether or not parachutes
are required. Other than that, I agree with you.

Tony V.
http://home.comcast.net/~verhulst/SOARING

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

"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