Broken stiffeners, Replace of Defer ?

[rmarshall234 13]

I've been replacing a ton of broken stiffeners lately. To me it's an airworthiness issue. What about you guys, what do you do and what do you think?

[fcajump 153]

rmarshall234

I've been replacing a ton of broken stiffeners lately. To me it's an airworthiness issue. What about you guys, what do you do and what do you think?

Replace.

I think I'm the only one around here that does stiffeners in National PEP's, but yes... replace.

Sometimes because it is what the PC launches off of, sometimes because it holds the form, sometimes because it keeps the broken pieces from cutting into the fabric, sometimes it keeps the stray line from hooking around the flap, but always because that's how the mfg designed, tested, refined and built the system.

Might be out of sight, but that doesn't mean it can't be the first link in the chain.

JW

Always remember that some clouds are harder than others...

[riggerrob 558]

Like Mr. FCA,
I have replaced a dozen or so plastic staffeners in PEPs. The only difference is that I am replacing white nylatron stiffeners in the pack trays and side flaps of Slimline (clone of National) PEPs made in Canada.

I have also replaced dozens of cracked stiffeners in sport containers. The majority were in over-stuffed main containers, but I have also repaired a few over-stuffed reserve containers.

My pet peeve is replacing cracked main riser cover tuck-tabs. Tolerances are very tight making it doubly difficult to re-use old binding tape. The worst part is that most cracked stiffeners could be avoided by RTFM. Hint: the Javelin post-2,000 manual works great on Javelins built after the turn of the century. OTOH if you use the new manual to pack old Javelins (made in the previous century), the top of the reserve container ends up too bulky, causing riser covers to pop open, or - worse - fracked.

As for whether to defer fracked stiffeners ..... NOT!
Because the longer you wait, the more expensive the repair. For example, R.I. repairs cracked stiffeners by replacing the entire flap .... a process that requires patterns that are never seen outside the factory.

Finally, if you are replacing cracked stiffeners, only install grey, durable, Nylatron that is lubricated with molybdenum disulphide.

[RiggerLee 61]

One issue I've seen in stiffeners with a grommet through them is the size of hole punched. If you use a normal... 0A? punch to make the hole it will be too small. If you see the plastic trying to pucker out after you set the grommet that implies that the hole is too small. You have a lot of stress built up in the plastic around the grommet. The grommet flares outwards and expands when you set it. Ok for fabric but a problem with hard plastics. You see the same thing with Polycarbonate or things like that. Setting rivets through it, like making a slide up door. You have to drill the hole in the plastic larger so the rivet will not stress it.

So use a slightly larger punch. Like... 1A? I'm too lazy to go down stares and check the numbers on my punches.

Lee

Lee
[email protected]
www.velocitysportswear.com

[indyz 1]

I use a 3/8" hole, which I believe is a #3 punch.

[rmarshall234 13]

>but always because that's how the mfg designed, tested, refined and built the system.

Precisely. And that's one reason I replace them too. The FAA's definition of airworthy is that it comforms to it's original design and is in a safe condition for flight.

The other reason I replace them is because I once watched (from 4 feet away) a teeny tiny burr on a grommet catch a pilot chute and cause what would have become a total malfunction had the reserve side instructor not reached over and pulled the PC clear. The sharp edge of a broken stiffener could do the same thing.

>Might be out of sight, but that doesn't mean it can't be the first link in the chain.

Exactly. And that's the mindset I want from the guy or gal packing my reserve. Very nice.

[rmarshall234 13]

>One issue I've seen in stiffeners with a grommet through them is the size of hole punched.

Yes! The Riggers Handbook by Sandy Reid mentions the importance of making a 3/8 inch hole for a size 0 grommet for the exact reason you mention. I even go so far as to use a Woodworkers drill bit instead of a standard twist drill which makes a much cleaner hole w/o setting up a stress riser in the material.

[SmokeyBear 0]

fcajump

...sometimes it keeps the stray line from hooking around the flap...

This. The stiffener is designed to give the flap a tapered shape to allow lines to slide off of it. If the stiffener is broken, a loop of line can half-hitch around the flap and get stuck there, cinching up tight behind the broken stiffener. That gives the main canopy a violent spin, and if you cut it away, you'll still have it in-tow behind you. So now you have to dump your reserve into the streamer. People have died from this. RIP John Appleton.

Replace the stiffeners. ASAP!

[rmarshall234 13]

>The stiffener is designed to give the flap a tapered shape to allow lines to slide off of it. If the stiffener is >broken, a loop of line can half-hitch around the flap and get stuck there, cinching up tight behind the broken >stiffener.

Excellent. This is one possibility I had not yet considered but you are absolutely right.

>Replace the stiffeners. ASAP!

Amen. When it comes to parachutes I go by the simple philosophy: if it ain't right fix it. The Grim Reaper is always looking for an opportunity to exploit.

[rmarshall234 13]

Thanks for the comments guys.

One last question: I usually charge $50 to replace a stiffener and I'm primarily doing PEPs. Is this too much? The customers don't usually complain about the price, but seem surprised that there is an additional charge.

Thanks again.

[hackish 8]

I think it's fair and the billing is just an exercise in communication. You need a way to communicate that it's not something simple like replacing a rubber band. The invoice should read something to the effect of repair broken stiffener. I normally put materials and labour separately. $5 for grommet, $10 for plastic and $35 for labour. As you like but I feel it communicates what went into the repair, not just an arbitrary $50 on top.

-Michael

[rmarshall234 13]

Nice.

I'm currently returning the broken stiffener parts and pizza-cut grommets but I'll break-out the costs as you suggest. I think that's a good idea, thanks.

[riggerrob 558]

Many lofts have written policies stating that if they need to do repairs less than $30. they will not bother phoning the customer to ask for permission.
Repairs costing $50. deserve a phone call or e-mail.

After failing to reach some customers two or three times, I have simply billed them $30 (for a more expensive repair) just to keep rigs moving through the loft.

Caution: casual readers: I might be calling to ask for your approval on a more expensive repair. That repair might require shipping high-wear, rare items (e.g. main risers) across international borders or sending your rig back to the factory for major repairs. There is no way I can find a second-hand, airworthy pair of risers for $30.
Hah!
Hah!
IOW you can buy $30 risers or you can buy airworthy risers: pick one.

[rmarshall234 13]

>Many lofts have written policies stating that if they need to do repairs less than $30. they will not bother >phoning the customer to ask for permission.
>Repairs costing $50. deserve a phone call or e-mail.

Calling or sending an email is my usual practice as well but I haven't applied it 100% of the time. However, I will now and will adopt the $30 rule. Thanks.