Why stiffeners in the main flaps?

[skydiverek 63]

On vast majority of rigs there are plastic stiffeners built into the main container flaps. Also, I recall two line-flap entalglements, one of them fatal. Both on Javelins. Question is: I know one you may shape the main flap ending in a way, which lessens the chance of having the lines half-hitch. But why are the plasic stiffeners used there in the first place? Racer does not use them, for example.

[piisfish 140]

-might depend on the shape of the flaps, it seems to me that most of the flaps I have seen would be more "snaggable" without the plastic stiffener, as it would be easier to half-hitch around the fabric and a grommet

-so "you" can replace it with another material and glue it so I can bitch about it on the interwebz

I can't say for a Racer as I almost never saw one.

scissors beat paper, paper beat rock, rock beat wingsuit - KarlM

[JohnSherman 1]

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without the plastic stiffener, as it would be easier to half-hitch around the fabric and a grommet

Try it. You won't snag a flap on a Racer.

[piisfish 140]

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without the plastic stiffener, as it would be easier to half-hitch around the fabric and a grommet

Try it. You won't snag a flap on a Racer.

thanks for that hint John, will try as soon as I get my hands on one. This is why I precised "on many of the flaps that I know of"... and "almost never saw a Racer"
But I hope that you can show me more, in person, in 6 weeks time at Skydive Expo

scissors beat paper, paper beat rock, rock beat wingsuit - KarlM

[LouDiamond 1]

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I can't say for a Racer as I almost never saw one.

What about that time at Rigger camp? I know there was a Racer there, I did a reserve pack job on it as a matter of fact. But I will say that it was a very old Racer and not what one would expect to see on todays Racer.


John, if you have a newer style Racer laying around that you would like to donate to Sandy's rigging course I know the students would have more of an opportunity to work on a Racer thats closer to what comes from the factory today.

"It's just skydiving..additional drama is not required"
Some people dream about flying, I live my dream
SKYMONKEY PUBLISHING

[piisfish 140]

I think I packed a Reflex, not a Racer, should check in my logbook.
And in all honesty , I did not necessarily pay full attention to the flaps of the main tray on the rigs we were packing.
I actually think the closest I was to touching a Racer was yours

scissors beat paper, paper beat rock, rock beat wingsuit - KarlM

[Deyan 36]

My best guess will be because the designers want their "babies" to look cool. By using stiffeners they reduce the tension from one point ( the grommet) to the whole flap, making it less likely to wrinkle . The down side from this is that if a line half hitches the flap, you are in really deep st.

John should correct me if I'm wrong, but the only "stiffener" used in Racer is Type 4 square weave. But I guess that the purpose is to give a little bit more flesh so the container fabric is not going to be pulled from the grommet.

I asked myself the same question when I had to replace 6 broken stiffeners in one rig

"My belief is that once the doctor whacks you on the butt, all guarantees are off" Jerry Baumchen

[pchapman 279]

I've also thought that the main reason for stiffeners is to spread the load, anchor the grommet securely, and avoid wrinkling.

The Racer side flaps without hard stiffeners are not the "last flaps" like on many designs -- a top flap is the last one to close (unless anything has changed recently). So that hides the side flaps somewhat. On the other hand, on the Racer I use, the side flaps are in good condition after a lot of use, with just the type 4 tape reinforcement around the grommet.

While lines tangling with flap stiffeners is very rare, I have an aversion to rigs with stiff flap ends, but very soft & floppy flaps, especially if they don't taper down to the tip quickly. A hard chunk way out at the end of a soft flap is not an ideal design.

[theonlyski 8]

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Racer does not use them, for example.

Then I must have a one-off racer sitting in front of me, it's got stiffeners on the top and bottom flaps.

"I may be a dirty pirate hooker...but I'm not about to go stand on the corner." iluvtofly
DPH -7, TDS 578, Muff 5153, SCR 14890
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[skydiverek 63]

I was talking about side flaps.

[riggerrob 643]

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I've also thought that the main reason for stiffeners is to spread the load, anchor the grommet securely, and avoid wrinkling.

The Racer side flaps without hard stiffeners are not the "last flaps" like on many designs -- a top flap is the last one to close (unless anything has changed recently). So that hides the side flaps somewhat. On the other hand, on the Racer I use, the side flaps are in good condition after a lot of use, with just the type 4 tape reinforcement around the grommet.

While lines tangling with flap stiffeners is very rare, I have an aversion to rigs with stiff flap ends, but very soft & floppy flaps, especially if they don't taper down to the tip quickly. A hard chunk way out at the end of a soft flap is not an ideal design.

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The worst possible configuration is high aspect ratio, with a huge stiffener in the end.

OTOH the configuration least likely to snag lines is low aspect ratio with no stiffeners ... merely a piece of webbing to spread loads from the grommet.