Almost perfect payout winch launch.

At 14:07 07 May 2013, Bill D wrote:
On Monday, May 6, 2013 10:46:40 PM UTC-6, Waveguru wrote:
If we had slowed down a little, and tightened up the tension a bit, we
could have added a couple hundred more feet? What do you think about the
"Payout Winch"?



http://www.youtube.com/watch?v=f5WDiHHgua8



Boggs

I think if you had a real winch and learned how to use it safely, you'd
get
a lot higher.

I think that is the most complicated and potentially dangerous method of
winch launching that I have ever seen.
I am completely sold on winching, having made over 10000 launches on many
types of winch over the years. I have to say that some of the winches I
have used, including a converted Rover car have been less than ideal, and
perhaps a little unwise, but this has to be the most foolhardy version I
have ever come across.
I would be the first to admit that there are several potential hazards in
winch launching but a system as complex as that is an accident just waiting
to happen. Please stop it guys, get a proper conventional winch if that is
the way you want to go, or go to a straight forward auto tow.

On Tuesday, May 7, 2013 11:02:14 AM UTC-5, Don Johnstone wrote:
At 14:07 07 May 2013, Bill D wrote: On Monday, May 6, 2013 10:46:40 PM UTC-6, Waveguru wrote: If we had slowed down a little, and tightened up the tension a bit, we could have added a couple hundred more feet? What do you think about the "Payout Winch"? http://www.youtube.com/watch?v=f5WDiHHgua8 Boggs I think if you had a real winch and learned how to use it safely, you'd get a lot higher. I think that is the most complicated and potentially dangerous method of winch launching that I have ever seen. I am completely sold on winching, having made over 10000 launches on many types of winch over the years. I have to say that some of the winches I have used, including a converted Rover car have been less than ideal, and perhaps a little unwise, but this has to be the most foolhardy version I have ever come across. I would be the first to admit that there are several potential hazards in winch launching but a system as complex as that is an accident just waiting to happen. Please stop it guys, get a proper conventional winch if that is the way you want to go, or go to a straight forward auto tow.

i'm interested to hear more about your opinion. Gary's payout winch basically has built in tension control in that if, say, the glider hits a thermal on the climb, instead of the line loading up and breaking, it just lets out more line so you get to use that thermal to climb higher.

hang glider guys use payout winches a lot to launch in the flat lands.

On 5/7/2013 9:23 AM, Tony wrote:
On Tuesday, May 7, 2013 11:02:14 AM UTC-5, Don Johnstone wrote:
At 14:07 07 May 2013, Bill D wrote: On Monday, May 6, 2013 10:46:40 PM UTC-6, Waveguru wrote: If we had slowed down a little, and tightened up the tension a bit, we could have added a couple hundred more feet? What do you think about the "Payout Winch"? http://www.youtube.com/watch?v=f5WDiHHgua8 Boggs I think if you had a real winch and learned how to use it safely, you'd get a lot higher. I think that is the most complicated and potentially dangerous method of winch launching that I have ever seen. I am completely sold on winching, having made over 10000 launches on many types of winch over the years. I have to say that some of the winches I have used, including a converted Rover car have been less than ideal, and perhaps a little unwise, but this has to be the most foolhardy version I have ever come across. I would be the first to admit that there are several potential hazards in winch launching but a system as complex as that is an accident ju
st waiting to happen. Please stop it guys, get a proper conventional winch if that is the way you want to go, or go to a straight forward auto tow.

i'm interested to hear more about your opinion. Gary's payout winch basically has built in tension control in that if, say, the glider hits a thermal on the climb, instead of the line loading up and breaking, it just lets out more line so you get to use that thermal to climb higher.

hang glider guys use payout winches a lot to launch in the flat lands.


Their stall speed is a lot slower. I am not sure that I understand how
you could use a payout winch with a glider unless the truck is driving
at a tremendous speed.

On Tuesday, May 7, 2013 10:26:31 AM UTC-6, Greg Arnold wrote:
On 5/7/2013 9:23 AM, Tony wrote:

On Tuesday, May 7, 2013 11:02:14 AM UTC-5, Don Johnstone wrote:

At 14:07 07 May 2013, Bill D wrote: On Monday, May 6, 2013 10:46:40 PM UTC-6, Waveguru wrote: If we had slowed down a little, and tightened up the tension a bit, we could have added a couple hundred more feet? What do you think about the "Payout Winch"? http://www.youtube.com/watch?v=f5WDiHHgua8 Boggs I think if you had a real winch and learned how to use it safely, you'd get a lot higher. I think that is the most complicated and potentially dangerous method of winch launching that I have ever seen. I am completely sold on winching, having made over 10000 launches on many types of winch over the years. I have to say that some of the winches I have used, including a converted Rover car have been less than ideal, and perhaps a little unwise, but this has to be the most foolhardy version I have ever come across. I would be the first to admit that there are several potential hazards in winch launching but a system as complex as that is an accident ju

st waiting to happen. Please stop it guys, get a proper conventional winch if that is the way you want to go, or go to a straight forward auto tow.



i'm interested to hear more about your opinion. Gary's payout winch basically has built in tension control in that if, say, the glider hits a thermal on the climb, instead of the line loading up and breaking, it just lets out more line so you get to use that thermal to climb higher.



hang glider guys use payout winches a lot to launch in the flat lands.





Their stall speed is a lot slower. I am not sure that I understand how

you could use a payout winch with a glider unless the truck is driving

at a tremendous speed.

That's the basic problem. Payout winches are less a winch launch than auto-tow with a variable rope length and a built-in rope management system. In a traditional auto-tow, you must set aside enough distance for the tow vehicle to accelerate to tow speed and then stop at the far end plus the rope length - what's left is used for the launch.

The payout scheme helps with the acceleration phase in that the tow vehicle can accelerate while paying out rope so the acceleration distance and rope length requirements overlap then at the departure end, the tow vehicle can stop as fast as possible while the on-board winch pulls in the slack rope. All this is much easier with a slow hang glider.

The takeoff roll seemed slow and the climb angle seemed shallow similar to auto-tow indicating the height achieved was lower than traditional winches where the takeoff roll is very short and the climb angle is around 45 degrees.

Low achieved height can be a safety issue. I call it the "end trap" where the glider reaches the departure end without enough height to safely turn back and nowhere to land ahead. This doesn't mean I think what Gary is doing is unsafe. That depends on the options available to the pilot in the event of a launch failure.

A few safety issues safety issues.
The strop. i.e. the rope between the rings and the parachute appears to be
very flexible. If the glider roles forward when taking up slack and overuns
the cable it can easily get caught in the wheel box meaning the glider
cannot release at the top of the launch. Encasing this bit of rope in a
plastic tube (garden hose) should aleviate the problem.

This strop should also be quite long. We were using a short one at Lasham
for years until we had a winch failure just as the glider left the ground.
The chute opened and draped itself over the cockpit when the glider was a a
few feet in the air. A wonderful cure for constipation.

The payout winch does not appear to have any form of guilotine.
If the glider cannot release you need to have some way of freeing it from
the winch so it has a chance to make a landing.

The BGA advice on winch launching can be found here_
http://www.gliding.co.uk/bgainfo/saf...hlaunching.htm

Here's another video of our payout winch in operation at the Alvord Desert:

http://www.youtube.com/watch?v=oP8bVgG8xJc

Boggs

Don, I can respect that you have reservations about the method in
question. But it would be a lot more constructive if you'd provide
specific examples of why the method in question is inadvisable, and
are prepared to tell us how it can go wrong. Otherwise, when you call
people "foolhardy" and tell them flat out to "stop it," you mostly
just come across as a disagreeable curmudgeon.

Furthermore, I think that anybody who has used a winch but decries the
"complexity" of other ground launch methods does not really understand
how complex a good winch is, and how many points of failure there
really are.

Thanks, Bob K.

On May 7, 9:02*am, Don Johnstone wrote:

I think that is the most complicated and potentially dangerous method of
winch launching that I have ever seen.
I am completely sold on winching, having made over 10000 launches on many
types of winch over the years. I have to say that some of the winches I
have used, including a converted Rover car have been less than ideal, and
perhaps a little unwise, but this has to be the most foolhardy version I
have ever come across.
I would be the first to admit that there are several potential hazards in
winch launching but a system as complex as that is an accident just waiting
to happen. Please stop it guys, get a proper conventional winch if that is
the way you want to go, or go to a straight forward auto tow.

At 02:45 10 May 2013, Bob Kuykendall wrote:
Don, I can respect that you have reservations about the method in
question. But it would be a lot more constructive if you'd provide
specific examples of why the method in question is inadvisable, and
are prepared to tell us how it can go wrong. Otherwise, when you call
people "foolhardy" and tell them flat out to "stop it," you mostly
just come across as a disagreeable curmudgeon.

Furthermore, I think that anybody who has used a winch but decries the
"complexity" of other ground launch methods does not really understand
how complex a good winch is, and how many points of failure there
really are.

Thanks, Bob K.

Fair point Bob

If we consider the simplest winch where the engine is connected to a
transmission via a gearbox of some kind. In this type of winch the driver
is seated and controls the throttle to control the speed of cable
retrieval.

What can go wrong? Three basic things as regards the operation of the
winch.

1. A break in the cable
2. A mechanical failure of the winch
3. Winch driver error or incapitation.

All of these eventualities are dealt with by practising launch failures or
launch abandonment. As far as mechanical failure of the winch is concerned
there are only two main components to fail, the engine (Uncommon but not
unknown) and the transmission. In all cases the winch driver is seated with
a good view of what is going on and can react to problems as they arise, in
particular using the guillotine if required in a timely manner.
The first winch I drove was of this time, a 3 litre petrol engine driving a
winch drum through a conventional 4 speed gearbox.
The most complex winch I have driven was a Munster Van Gelder winch with a
ginormous turbo diesel engine providing power for 6 seperate drums through
a torque converter. The engine control, transmission and drum select
functions were complex but once the transmission was connected to the power
module the principle was the same as for the simple Eagle winch described
above. Failure of either winch by mechanical failure of the
engine/transmission during launching was very rare. The MVG winch was
however less reliable in that faults within the more complex system meant
that it was U/s far more often than the simple winch, and took longer to
fix. Having said that the components making up the MVG winch were of top
quality and specifcally designed or adapted to provide the proper function,
it was just that there were more components to go wrong. In both cases the
winch was fixed, the driver had control and could see the glider at all
times and take the appropriate action.

The payout winch provides an additional level of complexity and reduces the
ability of the operator to control the launch. Some aspects of the launch
rely totally on unsupervised mechanical/electrical operations, the payout
part of the operation. The system is really a combination of two launch
methods, an auto tow and a winch launch and is just one level of complexity
too much when the proven technology already exists to provide a good
launch without introducing more complex procedures, especially ones which
rely totally on a mechanical/electrical function with no human input or
control.
During an auto tow the driver is facing the wrong way or is peering over
his shoulder so his ability to offer proper control or reaction to an
emergency is compromised, add to that the fact that cable payout is taking
place while the vehicle is moving in the opposite direction and while the
glider is on the cable and the things that can go wrong increases
exponentially.
Winch launching has hazards, no denying that, some of them completely
outside the control of the winch operator. A fixed winch with the operator
in a good position to observe the launch provides the best and safest
solution.
I have of course assumed that the launch is contolled by one person, the
implications of having two people controlling a launch (or not) are too
horrible to consider. I cannot see that anyone would be daft enough to do
that.
I can see that the payout winch launch is dangerous, I have said so. I may
or may not be believed. Like all human activity it will continue until
something goes wrong. If god forbid someone is killed then many people will
pipe up saying they knew it was dangerous, I am just saying it in the vain
hope that people will look at what they are doing and see that however
attractive it might seem it is not woth the risks, before it ends in
tears.
Bottom line, a vehicle driving down a runway with a glider on tow and a
winch paying out cable while the launch is taking place is not something
that I would ever be involved in. Been gliding and winching for 50 years
and would like to continue for a few more years.

On Friday, May 10, 2013 8:11:07 AM UTC-4, Don Johnstone wrote:
The system is really a combination of two launch
methods, an auto tow and a winch launch and is just one level of complexity
too much when the proven technology already exists to provide a good
launch without introducing more complex procedures, especially ones which
rely totally on a mechanical/electrical function with no human input or
control.

The opposite of Don, I have ZERO experience with winch launches, so I look at the approach with a completely naive perspective. If you think that my inexperience means that I should not comment on what I see, then stop reading now. I have no opinion, but I have a few questions.

The system is really a combination of two launch
methods, an auto tow and a winch launch...

From my naive point of view, this launch starts out as an autotow. How is this phase of the launch different than a traditional autotow? Waveguru depends on the clutch on the payout winch to modulate the tension on the line.. What are the failure modes for this clutch and what are the consequences? Would it be safer to lock the clutch and start the tow with the line under tension (rather than the truck taking the "running start"? Is a traditional autotow more failure prone and/or dangerous than a winch launch?

Once the autotow phase of the launch is completed, the glider is several hundred feet in the air. All of the bad things that can happen with a winch launch close to the ground have been sidestepped.

(waveguru's method introduces) more complex procedures, especially ones which
rely totally on a mechanical/electrical function with no human input or
control.

Again, naively, in a rapidly developing situation, whenever "time is of the essence" and extremely short, I would generally trust a properly designed and constructed mechanical or electrical mechanism to effect the correct response much more than I would trust a human operator. Is there a reason why a human operator would be more trustworthy in this situation?

Okay. I do have a few observations/opinions:

1)That the payout winch payouts more line and keeps line tension constant when the glider hits lift seems an inherent advantage of this approach when compared to a traditional winch launch.

2)Don's suggestion that traditional winch launching is proven and that there is therefore no reason to experiment with payout winching misses the point. In a country where beefy pickup trucks are common, the start-up costs for payout winching are much lower than traditional winching. Secondly, far fewer humans need to be deployed and coordinated to run a payout winch. The relevant question is "Which is better to use on a dry lake bed, 1)autotow with payout winch or 2)traditional autotow? What are the tradeoffs?

On Friday, May 10, 2013 7:19:27 AM UTC-6, son_of_flubber wrote:

Okay. I do have a few observations/opinions:

1)That the payout winch payouts more line and keeps line tension constant when the glider hits lift seems an inherent advantage of this approach when compared to a traditional winch launch.

If a glider can hit at thermal, it can also hit sink. A conventional winch can call on huge reserves of power to pull the glider through sink but the payout winch is more limited in this ability.


2)Don's suggestion that traditional winch launching is proven and that there is therefore no reason to experiment with payout winching misses the point. In a country where beefy pickup trucks are common, the start-up costs for payout winching are much lower than traditional winching. Secondly, far fewer humans need to be deployed and coordinated to run a payout winch. The relevant question is "Which is better to use on a dry lake bed, 1)autotow with payout winch or 2)traditional autotow? What are the tradeoffs?

If space is essentially unlimited, as is sometimes the case on dry lakes, a traditional auto-tow is both simpler and safer. When space is limited, as on a runway, conventional winches will prove more efficient and, I think, safer. I've run the numbers several times and a conventional winch will always get you higher than a payout winch given a limited runway length. Don's point that a conventional winch is simpler is valid. In the extreme it only requires as many people as aero tow.

The conventional winch is a very mature technology with an enormous body of safety data. In the 7 or 8 decades of its history, the potentially dangerous aspects have been found and procedures developed to minimize them. Germans manage 180,000 winch launches or so between accidents where we have an aero tow accident roughly every 26,000 tows. Unfortunately, the Brits suffer a winch accident every 16,000 launches which calls their methods into question. No one knows what the accident rate with payout winches would be, but until everyone climbs the learning curve, I suspect it won't be stellar.