Parachute source for gliders and winches

[JS[_5_]]

Saw the ad in the AMA flyer for their Expo in Pomona. SSA Region 12 has a presence there.
AMA Expo:
https://amablog.modelaircraft.org/amaexpowest/files/2018/10/expowest-program-2018-web.pdf

Fruity Chutes looks like a good source for chutes, including ballistic chutes.
Anything from 12" diameter up.
Jim

https://fruitychutes.com/

[Soartech]

In case you did not know it, there are many small (~3 foot diameter) parachutes available for minimal cost on Amazon, Walmart.com, etc. Search on running parachutes, drag chutes, exercise parachutes, etc. They are used to add drag to increase effort during exercise.

[Martin Gregorie[_6_]]

On Wed, 31 Oct 2018 09:06:05 -0700, JS wrote:

> Saw the ad in the AMA flyer for their Expo in Pomona. SSA Region 12 has
> a presence there.
> AMA Expo:
> https://amablog.modelaircraft.org/amaexpowest/files/2018/10/expowest-
program-2018-web.pdf
>
> Fruity Chutes looks like a good source for chutes, including ballistic
> chutes.
> Anything from 12" diameter up.
> Jim
>
> https://fruitychutes.com/

The Fruity chutes I looked at would all be unlikely to survive their
first winch launch: thie all emphasized light weight, which is exactly
what you don't want for winching. The winch parachute is inline between
cable and shock cord. The tension being carried through the 'chute keeps
it closed during the 60-65 knot launch, when the 'underside' of the
'chute is facing the winch and the shock cord, connecting chute to
glider, it attached to the top centre of its bell. If the launch didn't
finish it off a light weight chute, then being dragged back to the winch
after the launch would probably do the trick.

That is why traditional winch chutes are made of heavy duty canvas with
typically four shrouds made of 50-75mm heavy duty webbing sewn onto the
shock cord attachment at the centre of the chute. Current manufacture
chutes often use plastic fabric, but its just as thick as the canvas it
replaces.


--
Martin | martin at
Gregorie | gregorie dot org

[son_of_flubber]

On Thursday, November 1, 2018 at 7:05:15 PM UTC-4, Soartech wrote:
> In case you did not know it, there are many small (~3 foot diameter) parachutes available for minimal cost on Amazon, Walmart.com, etc. Search on running parachutes, drag chutes, exercise parachutes, etc. They are used to add drag to increase effort during exercise.

The parachutes used at the end of the winch cable need to be very heavy duty.
They get dragged along the ground at high speed when the line is rewound onto the spools after the glider releases.

One time I stress-tested the parachute by putting it into a fast moving river that ran parallel to the runway. Newbie me did not adequately compensate for a strong crosswind on a 2000 foot AGL launch. The parachute opened and caught the current.

[[email protected]]

On Thursday, November 1, 2018 at 6:18:55 PM UTC-6, Martin Gregorie wrote:
> On Wed, 31 Oct 2018 09:06:05 -0700, JS wrote:
>
> > Saw the ad in the AMA flyer for their Expo in Pomona. SSA Region 12 has
> > a presence there.
> > AMA Expo:
> > https://amablog.modelaircraft.org/amaexpowest/files/2018/10/expowest-
> program-2018-web.pdf
> >
> > Fruity Chutes looks like a good source for chutes, including ballistic
> > chutes.
> > Anything from 12" diameter up.
> > Jim
> >
> > https://fruitychutes.com/
>
> The Fruity chutes I looked at would all be unlikely to survive their
> first winch launch: thie all emphasized light weight, which is exactly
> what you don't want for winching. The winch parachute is inline between
> cable and shock cord. The tension being carried through the 'chute keeps
> it closed during the 60-65 knot launch, when the 'underside' of the
> 'chute is facing the winch and the shock cord, connecting chute to
> glider, it attached to the top centre of its bell. If the launch didn't
> finish it off a light weight chute, then being dragged back to the winch
> after the launch would probably do the trick.
>
> That is why traditional winch chutes are made of heavy duty canvas with
> typically four shrouds made of 50-75mm heavy duty webbing sewn onto the
> shock cord attachment at the centre of the chute. Current manufacture
> chutes often use plastic fabric, but its just as thick as the canvas it
> replaces.
>
>
> --
> Martin | martin at
> Gregorie | gregorie dot org

What Martin said..

Try this for a (relatively) cheap 'chute. Bite the bullet and buy one Tost small winch 'chute and take it to your local rigger and ask how much to make a replica. There's a good chance that will be much less than what you paid for the 1st 'chute.

[AS]

On Saturday, November 10, 2018 at 9:54:22 PM UTC-5, wrote:
> On Thursday, November 1, 2018 at 6:18:55 PM UTC-6, Martin Gregorie wrote:
> > On Wed, 31 Oct 2018 09:06:05 -0700, JS wrote:
> >
> > > Saw the ad in the AMA flyer for their Expo in Pomona. SSA Region 12 has
> > > a presence there.
> > > AMA Expo:
> > > https://amablog.modelaircraft.org/amaexpowest/files/2018/10/expowest-
> > program-2018-web.pdf
> > >
> > > Fruity Chutes looks like a good source for chutes, including ballistic
> > > chutes.
> > > Anything from 12" diameter up.
> > > Jim
> > >
> > > https://fruitychutes.com/
> >
> > The Fruity chutes I looked at would all be unlikely to survive their
> > first winch launch: thie all emphasized light weight, which is exactly
> > what you don't want for winching. The winch parachute is inline between
> > cable and shock cord. The tension being carried through the 'chute keeps
> > it closed during the 60-65 knot launch, when the 'underside' of the
> > 'chute is facing the winch and the shock cord, connecting chute to
> > glider, it attached to the top centre of its bell. If the launch didn't
> > finish it off a light weight chute, then being dragged back to the winch
> > after the launch would probably do the trick.
> >
> > That is why traditional winch chutes are made of heavy duty canvas with
> > typically four shrouds made of 50-75mm heavy duty webbing sewn onto the
> > shock cord attachment at the centre of the chute. Current manufacture
> > chutes often use plastic fabric, but its just as thick as the canvas it
> > replaces.
> >
> >
> > --
> > Martin | martin at
> > Gregorie | gregorie dot org
>
> What Martin said..
>
> Try this for a (relatively) cheap 'chute. Bite the bullet and buy one Tost small winch 'chute and take it to your local rigger and ask how much to make a replica. There's a good chance that will be much less than what you paid for the 1st 'chute.

We have been using this type of military surplus chute for years now and they hold up very well. The trick is to 'fly' the chute reasonably close to the winch and then drop it but not drag it over the ground.

https://www.ebay.com/itm/NEW-UNISSUED-MILITARY-5-FT-ORANGE-DROGUE-PARACHUTE-SEA-ANCHOR/142978932124?hash=item214a355d9c:g:GdkAAMXQnYJQ-pN1:sc:USPSPriority!29681!US!-1:rk:140:pf:0

Unfortunately, they have become harder and harder to find. Fortunately, I bought a few at a surplus store in TX, when they still had them. ;-)

Uli
'AS'

[Dan Marotta]

That's less expensive than a drag chute used in drag racing.Â* And for
our Brit friends, drag racing is not men in dresses and high heels
running a foot race... :-D

On 11/10/2018 7:54 PM, wrote:
> On Thursday, November 1, 2018 at 6:18:55 PM UTC-6, Martin Gregorie wrote:
>> On Wed, 31 Oct 2018 09:06:05 -0700, JS wrote:
>>
>>> Saw the ad in the AMA flyer for their Expo in Pomona. SSA Region 12 has
>>> a presence there.
>>> AMA Expo:
>>> https://amablog.modelaircraft.org/amaexpowest/files/2018/10/expowest-
>> program-2018-web.pdf
>>> Fruity Chutes looks like a good source for chutes, including ballistic
>>> chutes.
>>> Anything from 12" diameter up.
>>> Jim
>>>
>>> https://fruitychutes.com/
>> The Fruity chutes I looked at would all be unlikely to survive their
>> first winch launch: thie all emphasized light weight, which is exactly
>> what you don't want for winching. The winch parachute is inline between
>> cable and shock cord. The tension being carried through the 'chute keeps
>> it closed during the 60-65 knot launch, when the 'underside' of the
>> 'chute is facing the winch and the shock cord, connecting chute to
>> glider, it attached to the top centre of its bell. If the launch didn't
>> finish it off a light weight chute, then being dragged back to the winch
>> after the launch would probably do the trick.
>>
>> That is why traditional winch chutes are made of heavy duty canvas with
>> typically four shrouds made of 50-75mm heavy duty webbing sewn onto the
>> shock cord attachment at the centre of the chute. Current manufacture
>> chutes often use plastic fabric, but its just as thick as the canvas it
>> replaces.
>>
>>
>> --
>> Martin | martin at
>> Gregorie | gregorie dot org
> What Martin said..
>
> Try this for a (relatively) cheap 'chute. Bite the bullet and buy one Tost small winch 'chute and take it to your local rigger and ask how much to make a replica. There's a good chance that will be much less than what you paid for the 1st 'chute.

--
Dan, 5J

[Dan Marotta]

Credit to Monty Python...

On 11/11/2018 9:26 AM, Dan Marotta wrote:
> That's less expensive than a drag chute used in drag racing.Â* And for
> our Brit friends, drag racing is not men in dresses and high heels
> running a foot race... :-D
>
> On 11/10/2018 7:54 PM, wrote:
>> On Thursday, November 1, 2018 at 6:18:55 PM UTC-6, Martin Gregorie
>> wrote:
>>> On Wed, 31 Oct 2018 09:06:05 -0700, JS wrote:
>>>
>>>> Saw the ad in the AMA flyer for their Expo in Pomona. SSA Region 12
>>>> has
>>>> a presence there.
>>>> AMA Expo:
>>>> https://amablog.modelaircraft.org/amaexpowest/files/2018/10/expowest-
>>> program-2018-web.pdf
>>>> Fruity Chutes looks like a good source for chutes, including ballistic
>>>> chutes.
>>>> Anything from 12" diameter up.
>>>> Jim
>>>>
>>>> https://fruitychutes.com/
>>> The Fruity chutes I looked at would all be unlikely to survive their
>>> first winch launch: thie all emphasized light weight, which is exactly
>>> what you don't want for winching. The winch parachute is inline between
>>> cable and shock cord. The tension being carried through the 'chute
>>> keeps
>>> it closed during the 60-65 knot launch, when the 'underside' of the
>>> 'chute is facing the winch and the shock cord, connecting chute to
>>> glider, it attached to the top centre of its bell. If the launch didn't
>>> finish it off a light weight chute, then being dragged back to the
>>> winch
>>> after the launch would probably do the trick.
>>>
>>> That is why traditional winch chutes are made of heavy duty canvas with
>>> typically four shrouds made of 50-75mm heavy duty webbing sewn onto the
>>> shock cord attachment at the centre of the chute. Current manufacture
>>> chutes often use plastic fabric, but its just as thick as the canvas it
>>> replaces.
>>>
>>>
>>> --
>>> MartinÂ*Â*Â* | martin at
>>> GregorieÂ* | gregorie dot org
>> What Martin said..
>>
>> Try this for a (relatively) cheap 'chute.Â* Bite the bullet and buy
>> one Tost small winch 'chute and take it to your local rigger and ask
>> how much to make a replica.Â* There's a good chance that will be much
>> less than what you paid for the 1st 'chute.
>

--
Dan, 5J

[Charlie M. (UH & 002 owner/pilot)]

You talking RuPaul....?!?!
LOL......

If talking to Brits, be careful of fags or faggots......quite a bit different in the US than "Queens English"......;-)
[cigarettes or meatballs....in order.....]

[Martin Gregorie[_6_]]

On Sun, 11 Nov 2018 09:26:01 -0700, Dan Marotta wrote:

> That's less expensive than a drag chute used in drag racing.Â* And for
> our Brit friends, drag racing is not men in dresses and high heels
> running a foot race... :-D
>
..... but think of the possibilities if it was a hurdle race, the runners
were dressed in drag chutes and allowed to handbag each other while
hurdling. Who knows, that could be the latest teevee blockbuster.


--
Martin | martin at
Gregorie | gregorie dot org

[Charlie M. (UH & 002 owner/pilot)]

My understanding, walking (let alone running) in heels is tough...no, never tried either.....

As to suitability of one drag chute vs. another, seems like a major factor is if you drag it on the ground and whether or not it is pavement/macadam and load on the tow cable/wire.

[Dan Marotta]

The simple response to that is:Â* Don't drag it on the ground.Â* When I
was driving a winch back in the 90s, the technique was to increase
throttle sufficiently after the glider releases to keep the parachute
inflated and drop the chute right in front of the winch. The driver had
to have the skill to stop the drum before the chute got jammed in the
rollers.Â* On days without cross winds, just carry enough power to keep
the chute inflated until it lands.

On 11/11/2018 1:54 PM, Charlie M. (UH & 002 owner/pilot) wrote:
> My understanding, walking (let alone running) in heels is tough...no, never tried either.....
>
> As to suitability of one drag chute vs. another, seems like a major factor is if you drag it on the ground and whether or not it is pavement/macadam and load on the tow cable/wire.

--
Dan, 5J

[Frank Whiteley]

On Saturday, November 10, 2018 at 8:27:50 PM UTC-7, AS wrote:
> On Saturday, November 10, 2018 at 9:54:22 PM UTC-5, wrote:
> > On Thursday, November 1, 2018 at 6:18:55 PM UTC-6, Martin Gregorie wrote:
> > > On Wed, 31 Oct 2018 09:06:05 -0700, JS wrote:
> > >
> > > > Saw the ad in the AMA flyer for their Expo in Pomona. SSA Region 12 has
> > > > a presence there.
> > > > AMA Expo:
> > > > https://amablog.modelaircraft.org/amaexpowest/files/2018/10/expowest-
> > > program-2018-web.pdf
> > > >
> > > > Fruity Chutes looks like a good source for chutes, including ballistic
> > > > chutes.
> > > > Anything from 12" diameter up.
> > > > Jim
> > > >
> > > > https://fruitychutes.com/
> > >
> > > The Fruity chutes I looked at would all be unlikely to survive their
> > > first winch launch: thie all emphasized light weight, which is exactly
> > > what you don't want for winching. The winch parachute is inline between
> > > cable and shock cord. The tension being carried through the 'chute keeps
> > > it closed during the 60-65 knot launch, when the 'underside' of the
> > > 'chute is facing the winch and the shock cord, connecting chute to
> > > glider, it attached to the top centre of its bell. If the launch didn't
> > > finish it off a light weight chute, then being dragged back to the winch
> > > after the launch would probably do the trick.
> > >
> > > That is why traditional winch chutes are made of heavy duty canvas with
> > > typically four shrouds made of 50-75mm heavy duty webbing sewn onto the
> > > shock cord attachment at the centre of the chute. Current manufacture
> > > chutes often use plastic fabric, but its just as thick as the canvas it
> > > replaces.
> > >
> > >
> > > --
> > > Martin | martin at
> > > Gregorie | gregorie dot org
> >
> > What Martin said..
> >
> > Try this for a (relatively) cheap 'chute. Bite the bullet and buy one Tost small winch 'chute and take it to your local rigger and ask how much to make a replica. There's a good chance that will be much less than what you paid for the 1st 'chute.
>
> We have been using this type of military surplus chute for years now and they hold up very well. The trick is to 'fly' the chute reasonably close to the winch and then drop it but not drag it over the ground.
>
> https://www.ebay.com/itm/NEW-UNISSUED-MILITARY-5-FT-ORANGE-DROGUE-PARACHUTE-SEA-ANCHOR/142978932124?hash=item214a355d9c:g:GdkAAMXQnYJQ-pN1:sc:USPSPriority!29681!US!-1:rk:140:pf:0
>
> Unfortunately, they have become harder and harder to find. Fortunately, I bought a few at a surplus store in TX, when they still had them. ;-)
>
> Uli
> 'AS'

The orange chutes have become rare to non-existent, but work very well if you can source them. The similar option looks reasonable. Might have to order one to see if it's useful.

Frank Whiteley

[Martin Gregorie[_6_]]

On Sun, 11 Nov 2018 14:10:03 -0700, Dan Marotta wrote:

> The simple response to that is:Â* Don't drag it on the ground.Â* When I
> was driving a winch back in the 90s, the technique was to increase
> throttle sufficiently after the glider releases to keep the parachute
> inflated and drop the chute right in front of the winch. The driver had
> to have the skill to stop the drum before the chute got jammed in the
> rollers.Â* On days without cross winds, just carry enough power to keep
> the chute inflated until it lands.
>

Spot on for normal operation, but there is one unavoidable difference if
you're using Spectra rope.

On steel cable, you do the last launch of the day, suck the cable in,
pack the winch up and tow it back to its roost and everything is fine.

But if you do the same with Spectra rope, it will destroy the winch drums
because tightly wound Spectra is likely to crush the drum in overnight
cold, so after the last launch both cables are pulled out again. The
winch then pulls them in slowly enough to avoid inflating the chute. This
leaves the ropes loose enough on the drums to prevent crushing problems,
but has also dragged the 'chutes along the ground for the length of your
airfield.


--
Martin | martin at
Gregorie | gregorie dot org

[Dan Marotta]

I hesitate (not really) to ask how you learned what the Spectra could do.

I've only launched and driven with steel cable or plain rope with auto tow.

On 11/11/2018 4:26 PM, Martin Gregorie wrote:
> On Sun, 11 Nov 2018 14:10:03 -0700, Dan Marotta wrote:
>
>> The simple response to that is:Â* Don't drag it on the ground.Â* When I
>> was driving a winch back in the 90s, the technique was to increase
>> throttle sufficiently after the glider releases to keep the parachute
>> inflated and drop the chute right in front of the winch. The driver had
>> to have the skill to stop the drum before the chute got jammed in the
>> rollers.Â* On days without cross winds, just carry enough power to keep
>> the chute inflated until it lands.
>>
> Spot on for normal operation, but there is one unavoidable difference if
> you're using Spectra rope.
>
> On steel cable, you do the last launch of the day, suck the cable in,
> pack the winch up and tow it back to its roost and everything is fine.
>
> But if you do the same with Spectra rope, it will destroy the winch drums
> because tightly wound Spectra is likely to crush the drum in overnight
> cold, so after the last launch both cables are pulled out again. The
> winch then pulls them in slowly enough to avoid inflating the chute. This
> leaves the ropes loose enough on the drums to prevent crushing problems,
> but has also dragged the 'chutes along the ground for the length of your
> airfield.
>
>

--
Dan, 5J

[AS]

On Sunday, November 11, 2018 at 6:26:47 PM UTC-5, Martin Gregorie wrote:
> On Sun, 11 Nov 2018 14:10:03 -0700, Dan Marotta wrote:
>
> > The simple response to that is:Â* Don't drag it on the ground.Â* When I
> > was driving a winch back in the 90s, the technique was to increase
> > throttle sufficiently after the glider releases to keep the parachute
> > inflated and drop the chute right in front of the winch. The driver had
> > to have the skill to stop the drum before the chute got jammed in the
> > rollers.Â* On days without cross winds, just carry enough power to keep
> > the chute inflated until it lands.
> >
>
> Spot on for normal operation, but there is one unavoidable difference if
> you're using Spectra rope.
>
> On steel cable, you do the last launch of the day, suck the cable in,
> pack the winch up and tow it back to its roost and everything is fine.
>
> But if you do the same with Spectra rope, it will destroy the winch drums
> because tightly wound Spectra is likely to crush the drum in overnight
> cold, so after the last launch both cables are pulled out again. The
> winch then pulls them in slowly enough to avoid inflating the chute. This
> leaves the ropes loose enough on the drums to prevent crushing problems,
> but has also dragged the 'chutes along the ground for the length of your
> airfield.
>
>
> --
> Martin | martin at
> Gregorie | gregorie dot org

Martin,

steel cables do have the tendency to crush drums when not wound up after the last launch loosely, particularly if you were winching during a warm/hot summer day and experience a drop in temperature over night. Spectra is less affected by temperature swings but it is so tightly packed on the drum after the launch that it can crush a drum if left in that condition. We always pay out the line after the last launch and haul it it in at moderate speed, i.e. 1st gear at idle.
Dragging the chute several thousand feet over any kind of surface is just plain nuts! No wonder you are wearing it out in no time. Tie an old tire to the end, if you desire some resistance.

Uli
'AS'

[[email protected]]

Did Bill and Martin just agree on a winch related topic?!

[Martin Gregorie[_6_]]

On Sun, 11 Nov 2018 15:54:13 -0800, AS wrote:

> steel cables do have the tendency to crush drums when not wound up after
> the last launch loosely, particularly if you were winching during a
> warm/hot summer day and experience a drop in temperature over night.
>
When we used steel cable we didn't do anything special - just put the
winch, a Supacat, away with the cables wound from the last launches.
Maybe the Supacat drums were stronger than I realised: certainly the
whole winch looked to have been made with surplus battleship parts from
its air-cooled V8 diesel engine onward.

When we replaced the Supacat with a Skylaunch (and later added a Tost
that had been upgraded by Skylaunch) we switched to Spectra and the pull
out and rewind loosely after the last launch. Our field is mown grass
which doesn't obviously harm the heavy duty canvas and webbing parachutes
we use.

What I said initially applies only to those lightweight Fruity chutes.


--
Martin | martin at
Gregorie | gregorie dot org

[Martin Gregorie[_6_]]

On Sun, 11 Nov 2018 16:44:19 -0700, Dan Marotta wrote:

> I hesitate (not really) to ask how you learned what the Spectra could
> do.
>
There was feedback in S&G from early adopters about it and, when we
bought the Skylaunch I'm fairly certain it was in the operating manual.

Disclaimer: I regularly serve as part the airfield's normal operating
crew, but at the launchpoint and driving the cable tow-out truck. I had
some winch training on the Supercat, but don't drive the Skylaunch.

> I've only launched and driven with steel cable or plain rope with auto
> tow.
>
I never seen auto tow used - its very much a dieing art over here due to
the availability of good modern winches. Our longest cable run is just on
1km (3270 ft) long. Typical calm weather launches get to 1400ft but I've
had 2600-2700 ft on windy days with a decent velocity gradient in both
ASK-21 and SZD Juniors.


--
Martin | martin at
Gregorie | gregorie dot org

[[email protected]]

It's true that Spectra (Dyneema) has a thermal coefficient of expansion at 180 - 200 M/(MxK) - roughly 20X that for steel and 10X that for aluminum. Leaving it wound tightly on a cold night probably has caused drums to fail.

However, there's no need to drag the 'chute - that's what old tires are for.. Keep a couple handy with an eye-bolt through the tread to attach the rope to. Pulling a tire across the whole airfield can be done quickly at the end of the day leaving the Spectra wound loosely enough not to cause problems.

On Sunday, November 11, 2018 at 4:26:47 PM UTC-7, Martin Gregorie wrote:
> On Sun, 11 Nov 2018 14:10:03 -0700, Dan Marotta wrote:
>
> > The simple response to that is:Â* Don't drag it on the ground.Â* When I
> > was driving a winch back in the 90s, the technique was to increase
> > throttle sufficiently after the glider releases to keep the parachute
> > inflated and drop the chute right in front of the winch. The driver had
> > to have the skill to stop the drum before the chute got jammed in the
> > rollers.Â* On days without cross winds, just carry enough power to keep
> > the chute inflated until it lands.
> >
>
> Spot on for normal operation, but there is one unavoidable difference if
> you're using Spectra rope.
>
> On steel cable, you do the last launch of the day, suck the cable in,
> pack the winch up and tow it back to its roost and everything is fine.
>
> But if you do the same with Spectra rope, it will destroy the winch drums
> because tightly wound Spectra is likely to crush the drum in overnight
> cold, so after the last launch both cables are pulled out again. The
> winch then pulls them in slowly enough to avoid inflating the chute. This
> leaves the ropes loose enough on the drums to prevent crushing problems,
> but has also dragged the 'chutes along the ground for the length of your
> airfield.
>
>
> --
> Martin | martin at
> Gregorie | gregorie dot org

[son_of_flubber]

On Sunday, November 11, 2018 at 4:10:07 PM UTC-5, Dan Marotta wrote:
>...On days without cross winds, just carry enough power to keep
> the chute inflated until it lands.

I've never driven the winch, but I've sat in the cab and watched an international cadre of winching masters practice their art. At the two sites that I've done winch launches, operations continued in significant crosswind. Crosswinds seem to be less of a no-go with modern winches.

Additional factors make landing the parachute right in front of the winch challenging for even expert winch operators: 1)2000 foot launches means more time to drift 2)less experienced pilots (like me) that insufficiently compensate for the crosswind (by flying the launch to the upwind side of the field).

[Martin Gregorie[_6_]]

On Mon, 12 Nov 2018 20:06:57 -0800, son_of_flubber wrote:

> I've never driven the winch, but I've sat in the cab and watched an
> international cadre of winching masters practice their art. At the two
> sites that I've done winch launches, operations continued in significant
> crosswind. Crosswinds seem to be less of a no-go with modern winches.
>
On sites with severe cross-wind there's always the parachuteless option.
I've seen (and flown with) this setup at The Mynd,

The Mynd is on top of a long, steep north-south ridge with the runway
parallel to the ridge and close behind the soaring slope. Beyond the
runway there's an additional small rise with a valley containing moorland
and trees. When the ridge is working, launches and landings are flown in
a 90 degree cross-wind. Obviously they can't use a parachute on the
launch cable because, when the ridge is working well, the end of the
cable would end up over the hill and probably in the downwind forest: the
airfield is 250m across at its widest and scrub and trees start 100m
downwind of its lee edge.

They use a single drum winch with no parachute and the retrieval winch at
the launch point: the main cable ends in a metal triangle with the
retrieval cable on one corner and the shock rope and strop on the other.
No parachute.

During the launch a light cable streams off the small retrieval winch.
When the glider releases, the main winch is put in neutral and the
retrieval winch engages, causing the cable to snap down onto the main
runway, and shortly after that, its business end is back at the
launchpoint ready for the next launch. The two winch drivers co-ordinate
agreement about who is in gear and when by radio.


--
Martin | martin at
Gregorie | gregorie dot org

[[email protected]]

On Monday, November 12, 2018 at 9:06:59 PM UTC-7, son_of_flubber wrote:
> On Sunday, November 11, 2018 at 4:10:07 PM UTC-5, Dan Marotta wrote:
> >...On days without cross winds, just carry enough power to keep
> > the chute inflated until it lands.
>
> I've never driven the winch, but I've sat in the cab and watched an international cadre of winching masters practice their art. At the two sites that I've done winch launches, operations continued in significant crosswind. Crosswinds seem to be less of a no-go with modern winches.
>
> Additional factors make landing the parachute right in front of the winch challenging for even expert winch operators: 1)2000 foot launches means more time to drift 2)less experienced pilots (like me) that insufficiently compensate for the crosswind (by flying the launch to the upwind side of the field).

I've operated quite a number of different winches and always found it easy to drop the parachute exactly where I wanted it to land. My technique is to rip the 'chute down from the sky at high speed then stop the drum to drop the 'chute directly in front of the winch. A fast recovery of the rope and 'chute minimizes crosswind effects.

Obviously, this depends on a powerful brake which can dependably stop the drum exactly when you want - some testing is required to determine this. Despite occasional screams of panic from onlookers, I have never pulled a 'chute through the rollers nor tangled the cable/rope on the drum doing this.

[Bruce Hoult]

On Tuesday, November 13, 2018 at 3:37:00 AM UTC-8, Martin Gregorie wrote:
> On Mon, 12 Nov 2018 20:06:57 -0800, son_of_flubber wrote:
>
> > I've never driven the winch, but I've sat in the cab and watched an
> > international cadre of winching masters practice their art. At the two
> > sites that I've done winch launches, operations continued in significant
> > crosswind. Crosswinds seem to be less of a no-go with modern winches.
> >
> On sites with severe cross-wind there's always the parachuteless option.
> I've seen (and flown with) this setup at The Mynd,
>
> The Mynd is on top of a long, steep north-south ridge with the runway
> parallel to the ridge and close behind the soaring slope. Beyond the
> runway there's an additional small rise with a valley containing moorland
> and trees. When the ridge is working, launches and landings are flown in
> a 90 degree cross-wind. Obviously they can't use a parachute on the
> launch cable because, when the ridge is working well, the end of the
> cable would end up over the hill and probably in the downwind forest: the
> airfield is 250m across at its widest and scrub and trees start 100m
> downwind of its lee edge.

I don't understand.

At glider release the cable is pointing up into the sky at an angle of ... well, I don't know ... let's just say more than 60 degrees.

I've never seen a cable being wound in drop below an angle of ... let's say 30 degrees (more like 45 probably, but let's go with 30) until the parachute is within 100m of the winch and speed is falling off.

Half your 250m airfield width plus 100m to the trees is 225m. Even if the cable swings around directly downwind the parachute is going to be at least sin(30)*225 = 112m up when it crosses the trees. Your trees aren't that tall.

It's a different story if the cable breaks, of course.

[[email protected]]

On Wednesday, October 31, 2018 at 10:06:09 AM UTC-6, JS wrote:
> Saw the ad in the AMA flyer for their Expo in Pomona. SSA Region 12 has a presence there.
> AMA Expo:
> https://amablog.modelaircraft.org/amaexpowest/files/2018/10/expowest-program-2018-web.pdf
>
> Fruity Chutes looks like a good source for chutes, including ballistic chutes.
> Anything from 12" diameter up.
> Jim
>
> https://fruitychutes.com/

Winch 'chutes need to be VERY robust. I think the best scheme to get cheap winch 'chutes it to obtain an old Tost 'chute and have a parachute rigger make a copy using the Tost as a pattern. I've seen quotes of about $40 where Tost wants about $400. Obviously, you don't need a professional rigger to do this but they will have the heavy sewing machines required.