Line Replacement?

[JovialChris 0]

I have a "frayed" d-line about 4-6" above the riser connector link. What is the condition for line replacement (amount of fray). It is advisable to replace one line or should one just get a new line set? Trim issues? I have about 450-500 jumps on the canopy.

Appreciate input,

CE

JovialChris

I'm Lost! Which way to the Prairie?

[Hooknswoop 19]

w/ 450-500 jumps on the line set, it is either out of trim if it is Spectra or worn out if it is Vectran. A new line set would be the way to go. If your line set is Dacron, you are probably OK to just replace the one line. If you have HMA lines, they are still in trim, but some of them are probably worn and it would be a good idea to get a new line set.

Derek

[JovialChris 0]

Appreciate your insight Derek. I would say the crux of my concern is when should I stop using the canopy? Not that it is usable in Seattle this time of year, but I am planning on Eloy over the Holiday. It is a Spectra microline, about 1/8th of the width is frayed on the "inside side". Wouldn't have known, but I just did my annual meticulous gear check. Is there a rule-of-thumb as to what constitutes a "worn/ready to retire" line?

JovialChris

I'm Lost! Which way to the Prairie?

[Hooknswoop 19]

Quote

Appreciate your insight Derek. I would say the crux of my concern is when should I stop using the canopy? Not that it is usable in Seattle this time of year, but I am planning on Eloy over the Holiday. It is a Spectra microline, about 1/8th of the width is frayed on the "inside side". Wouldn't have known, but I just did my annual meticulous gear check. Is there a rule-of-thumb as to what constitutes a "worn/ready to retire" line?

Have a rigger look it over and check the line trim. You have time to get it relined before the x-mas boogie. If the trim is acceptable, then have them replace the one line and have fun. If the trim is bad, get it relined.

Rule-o-thumb is 10% of the total thickness worn/frayed, similar to closing loops.

Derek

[riggerrob 561]

I draw the line at one broken strand.
Sometimes I "partner" a line by fingertrapping another piece inside, but if your canopy has 500 jumps, it is probably due for a complete re-line anyways.
I believe the SR-71 was originally built by Parachute Industries of South Africa and only retailed by Ralph Hatley. PISA was recently absorbed by Aerodyne International, so to get a line kit for an SR-71, call Ralph Hatley in Oregon or ask Aerodyne International in Florida.
Aerodyne is pretty good about supplying line kits for canopies built by PISA. However they only trust a few riggers outside their shop to install line kits.
In the long run, it may be simpler to mail your SR-71 to Aerodyne and have them re-line it in Florida.

[DBCOOPER 1]

Quote

w/ 450-500 jumps on the line set, it is either out of trim if it is Spectra or worn out if it is Vectran

Could you explain exactly what out of trim is and what causes it?

Replying to: Re: Stall On Jump Run Emergency Procedure? by billvon

If the plane is unrecoverable then exiting is a very very good idea.

[Hooknswoop 19]

Quote

ould you explain exactly what out of trim is and what causes it?

Spectra is not 'dimensionally stable'. This means it shrinks when heated. The heat source is friction with the slider grommets, and to a lesser degree, the guide rings on the rear risers. The outer lines and steering lines recieve the most friction and therefore, heat. So they shrink more than the inner lines. Eventually, the outer lines and steering lines are much shorter than spec and the inner lines. The canopy's shape is distorted from spec and the canopy doesn't open or fly as it did when the lines were new/in trim.

725 lb Spectra lines are usually badly out of trim after 400-500 jumps. The smaller Spectra, 525, shrinks faster.

Derek

[DBCOOPER 1]

Would I be correct in assuming that it is an easily measurable variable? Would all of the lines in a group be the same length when new?

Replying to: Re: Stall On Jump Run Emergency Procedure? by billvon

If the plane is unrecoverable then exiting is a very very good idea.

[Hooknswoop 19]

Quote

Would I be correct in assuming that it is an easily measurable variable? Would all of the lines in a group be the same length when new?

Easy to measure?-yes All the same length when new?-depends on the canopy. You have to have the line trim specs from the manufacturer to know.

Derek

[Martini 0]

Hi Chris

This might be a good time to find the replacement canopy you've been looking for. Check the classifieds here, I have had only good experiences buying & selling here. The lineset will set you back close to $200, money better spent on a newer canopy. A good used Stiletto, Cobalt or Crossfire can be had for $ 600-800 with good lines, a Sabre 2 is harder to find used. Since you might also find a good deal at Eloy, having the rigger of your choice replace the one frayed line, if necessary, is an inexpensive alternative. You might also think about padding your old container (cheap) until you can find a replacement to fit your "new" and probably smaller canopy. Just my 2 cents. I'll be out Sunday if we get a weather break.

Sometimes you eat the bear..............

[Amazon 7]

I emailed Aerodyne and they gave me the particulars on our canopies.... RiggerRob is right.. it was a private label for Western Parachute Sales...ie Ralph Hatly.

This is basically the Text of the email I got back from them.

Glad you are pleased with your SR-71.

The SR-71 is a "Private-Label" canopy for Western Parachute Sales based on
our
"CONQUEST" Airfoil plan form.

The CONQUEST is an older design now , but is essentially a 9 cell zero
porosity
straight forward square (Rectangle) incorporating microline.

We sold quite a few CONQUESTS and SR-71's too over the years , but of course
ellipticals and semi-ellipticals came into the market and superseded these
traditional classic designs.

A SR-71 is a pretty large canopy with a maximum all up weight of 250 lbs.
The
spec's are 600 cu. in pack volume ; Span 24 Ft ; Chord 9.6 ; Aspect ratio is
2.5
(fairly longish for good glide and flare).

You can really pack it anyway that makes you comfortable. Flat pack ; stack

pack and Pro Pack as well. The guiding principles are ensuring the brakes
are
stowed , the lines have no twists , tangles and turns , and the slider is up
at the
canopy end when it comes time to place the canopy into the deployment bag
and
not down at the links.

As always , I'm sure Ralph gave you a fair deal so you received real value
for money
for your SR-71. When it comes time for a new Line Set (about 600 jumps or
so)
you can call Ralph or contact me for a replacement.


Just EMail Areodyne


[email protected]

Jeanne

[gemini 0]

Quote

The canopy's shape is distorted from spec and the canopy doesn't open or fly as it did when the lines were new/in trim.

Derrick is right on point, but understated. Bad things can happen when the canopy gets out of trim. The slider angle can change in relation to the relative wind and come down a lot faster resulting in much harder openings. In addition elliptical canopies will turn a lot more on deployment causing more line twists if you're not ready for them.

I can handle the line twists, but the last hard opening cost me $7,500 in medical bills.

When I sent the Sabre2 (with around 700 jumps on it) back to PD they called and said the lines were way out of trim and there were 4-5 holes that I had never noticed.

Save yourself and keep those lines in trim!

Blue skies,

Jim

[riggerrob 561]

The quickest way to tell if a canopy is out of trim is to measure the difference across the "A" lines.

When the difference across the "A" lines - on a rectangular canopy - reaches 3 inches, Brian Germain recommends replacing all the lines.

Measuring trim on tapered canopy is a bit more complex and requires a factory trim chart. PD trim charts are now available on their website. For trim charts from other manufacturers, ask your local Master Rigger.

Measuring shrinkage on steering lines is more complex for two reasons. First, you need a trim chart. Secondly, you need to know the secrets for reading that particular trim chart, you see ... some manufacturers measure lines on riser, while other manufacturers measure lines on a peg, etc. this is where your local Master Rigger comes in. ...