A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Soaring
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Parachute source for gliders and winches



 
 
Thread Tools Display Modes
  #11  
Old November 11th 18, 09:54 PM posted to rec.aviation.soaring
Charlie M. (UH & 002 owner/pilot)
external usenet poster
 
Posts: 1,383
Default Parachute source for gliders and winches

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.
  #12  
Old November 11th 18, 10:10 PM posted to rec.aviation.soaring
Dan Marotta
external usenet poster
 
Posts: 4,601
Default Parachute source for gliders and winches

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
  #13  
Old November 11th 18, 11:18 PM posted to rec.aviation.soaring
Frank Whiteley
external usenet poster
 
Posts: 2,099
Default Parachute source for gliders and winches

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/am...8/10/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-UNISSUE...-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

  #14  
Old November 12th 18, 12:26 AM posted to rec.aviation.soaring
Martin Gregorie[_6_]
external usenet poster
 
Posts: 699
Default Parachute source for gliders and winches

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
  #15  
Old November 12th 18, 12:44 AM posted to rec.aviation.soaring
Dan Marotta
external usenet poster
 
Posts: 4,601
Default Parachute source for gliders and winches

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
  #16  
Old November 12th 18, 12:54 AM posted to rec.aviation.soaring
AS
external usenet poster
 
Posts: 653
Default Parachute source for gliders and winches

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'
  #17  
Old November 12th 18, 03:41 AM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 107
Default Parachute source for gliders and winches

Did Bill and Martin just agree on a winch related topic?!
  #18  
Old November 12th 18, 01:07 PM posted to rec.aviation.soaring
Martin Gregorie[_6_]
external usenet poster
 
Posts: 699
Default Parachute source for gliders and winches

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
  #19  
Old November 12th 18, 01:20 PM posted to rec.aviation.soaring
Martin Gregorie[_6_]
external usenet poster
 
Posts: 699
Default Parachute source for gliders and winches

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
  #20  
Old November 12th 18, 06:46 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 51
Default Parachute source for gliders and winches

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


 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Parachute use in single seat gliders [email protected] Soaring 13 May 20th 16 04:14 PM
Anyone got a source... Jay Honeck[_2_] Home Built 12 November 17th 09 02:47 AM
SH-2F Seasprite from HSL-31 winches up its sonar Dave Kearton Aviation Photos 17 March 6th 07 05:10 AM
Source Mu Metal USA HL Falbaum Soaring 6 April 12th 06 03:53 PM
Winches (was Aerotow with Diesel engine? [email protected] Soaring 20 October 30th 04 05:27 AM


All times are GMT +1. The time now is 12:32 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AviationBanter.
The comments are property of their posters.