coil lock

[airnutt 8]

what are some of the ways a coil lock can occur, would it be rigger error or spring design

[mathrick 2]

Different coil designs are susceptible to locking under different circumstances, this is why it's critical to follow the manufacturer instructions. Whilst for many RPCs you're instructed to keep the fabric out of the coils, for some others (e.g. Stealth used by RI) you must tuck it inside the coils.

"Skydivers are highly emotional people. They get all excited about their magical black box full of mysterious life saving forces."

[ManBat 0]

"Coil lock" could mean two different things:
1) The coils of a pilot chute spring get caught on each other, or;
2) The pilot chute fabric is tucked under the base of the pilot chute, thereby locking the pilot chute in the compressed position by it's own tension.

For #1, this used to happen, rarely, when pilot chute springs were made with the same diameter throughout their entire length. A coil could interweave itself amongst another coil, thereby locking the coils together, effectively reducing it's length and effectiveness. Newer pilot chutes now have tapered springs, that are smaller diameter on the base, and larger diameter at the top. Thus it's more difficult for the coils to get caught on each other.

For #2, the practice used to be to stuff all the loose fabric under the base, but that meant that the pilot chute spring expansion was restricted because it was being held down by it's own skirt. The idea was that it helped serve as a good base "kicker plate" for launch, and also prevented a loose spring end from burrowing down into the canopy fabric and getting itself stuck there. I think the practice now is to stuff the loose fabric around the coils a little at a time along its entire length, so that it doesn't restrict expansion, or else lay the fabric outside the coils.

[piisfish 135]

I believe that your answer is "one way" to look at it.

My point of view is that springs come in different shapes and materials, and that they should be packed according to the manufacturers instructions.

I like some springs, I hate some others. To each his own

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

[riggerrob 558]

I have only seen "coil lock" once or twice. The spring was cylindrical, old and weak (Strong ?). And I doubt if it was packed according to a he manual. A middle coil slipped under the bottom coil.

I have never heard of "coil lock" on a conical spring: MA-1, Javelin, Racer, Vector, etc.

Again ..... if you don't understand something, pack it according to the manual.

[alexey 6]

If you will pack Wings reserve PC with material out of spring, you will have about 1 coil lock for 10 packs.
We find that on the testing.

And - plastic covered springs (like Wings\new Jav\RI) is more prone to coil lock, then metall - because of friction, obviously

Lexa

[hackish 8]

Every rig I pack is done exactly as specified in the manual. I've never seen a coil lock on a wings and I guarantee I've done more than 50.

As riggers, we are paid to follow instructions, not make stuff up.

-Michael

[alexey 6]

It is good to follow manual.
It is better to know why (in the manual) used that way.

Lexa

[riggerrob 558]

***"Coil lock" could mean two different things:
1) .......
2) The pilot chute fabric is tucked under the base of the pilot chute, thereby locking the pilot chute in the compressed position by it's own tension

For #2, the practice used to be to stuff all the loose fabric under the base ....... The idea was that it helped serve as a good base "kicker plate" for launch, and also prevented a loose spring end from burrowing down into the canopy fabric and getting itself stuck there. ........
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First time I have heard that!
.... but I have only been a rigger for 33 years .......

I do know that when military-surplus aluminum kicker plates got prohibitively expensive (1970s) many riggers substituted paper plates.
Since then, most sport containers have plastic (e.g. MDS Nylatron) kicker plates sewn into internal flaps.

[councilman24 36]

riggerrob

***"Coil lock" could mean two different things:
1) .......
2) The pilot chute fabric is tucked under the base of the pilot chute, thereby locking the pilot chute in the compressed position by it's own tension

For #2, the practice used to be to stuff all the loose fabric under the base ....... The idea was that it helped serve as a good base "kicker plate" for launch, and also prevented a loose spring end from burrowing down into the canopy fabric and getting itself stuck there. ........
-----------------------------------------------------------------------------

First time I have heard that!
.... but I have only been a rigger for 33 years .......

I do know that when military-surplus aluminum kicker plates got prohibitively expensive (1970s) many riggers substituted paper plates.
Since then, most sport containers have plastic (e.g. MDS Nylatron) kicker plates sewn into internal flaps.

I've had three Strong PEP's from two different riggers in different parts of the country. come through where the stuffed ALL the PC material into the CENTER bottom of the PC spring. Not into the sides, into the center of the bottom of the spring as far as they could. These PC's did no more than stand up.

I'm old for my age.
Terry Urban
D-8631
FAA DPRE

[councilman24 36]

riggerrob

***"Coil lock" could mean two different things:
1) .......
2) The pilot chute fabric is tucked under the base of the pilot chute, thereby locking the pilot chute in the compressed position by it's own tension

For #2, the practice used to be to stuff all the loose fabric under the base ....... The idea was that it helped serve as a good base "kicker plate" for launch, and also prevented a loose spring end from burrowing down into the canopy fabric and getting itself stuck there. ........
-----------------------------------------------------------------------------

First time I have heard that!
.... but I have only been a rigger for 33 years .......

I do know that when military-surplus aluminum kicker plates got prohibitively expensive (1970s) many riggers substituted paper plates.
Since then, most sport containers have plastic (e.g. MDS Nylatron) kicker plates sewn into internal flaps.

I've had three Strong PEP's from two different riggers in different parts of the country. come through where the stuffed ALL the PC material into the CENTER bottom of the PC spring. Not into the sides, into the center of the bottom of the spring as far as they could. These PC's did no more than stand up.

I'm old for my age.
Terry Urban
D-8631
FAA DPRE

[councilman24 36]

riggerrob

***"Coil lock" could mean two different things:
1) .......
2) The pilot chute fabric is tucked under the base of the pilot chute, thereby locking the pilot chute in the compressed position by it's own tension

For #2, the practice used to be to stuff all the loose fabric under the base ....... The idea was that it helped serve as a good base "kicker plate" for launch, and also prevented a loose spring end from burrowing down into the canopy fabric and getting itself stuck there. ........
-----------------------------------------------------------------------------

First time I have heard that!
.... but I have only been a rigger for 33 years .......

I do know that when military-surplus aluminum kicker plates got prohibitively expensive (1970s) many riggers substituted paper plates.
Since then, most sport containers have plastic (e.g. MDS Nylatron) kicker plates sewn into internal flaps.

I've had three Strong PEP's from two different riggers in different parts of the country. come through where the stuffed ALL the PC material into the CENTER bottom of the PC spring. Not into the sides, into the center of the bottom of the spring as far as they could. These PC's did no more than stand up.

I'm old for my age.
Terry Urban
D-8631
FAA DPRE

[32fps2 0]

Councilman! You're spinning out of control! Pull! PULL! PULL!

[32fps2 0]

riggerrob

***"Coil lock" could mean two different things:
1) .......
2) The pilot chute fabric is tucked under the base of the pilot chute, thereby locking the pilot chute in the compressed position by it's own tension

For #2, the practice used to be to stuff all the loose fabric under the base ....... The idea was that it helped serve as a good base "kicker plate" for launch, and also prevented a loose spring end from burrowing down into the canopy fabric and getting itself stuck there. ........
-----------------------------------------------------------------------------

First time I have heard that!
.... but I have only been a rigger for 33 years .......

I've heard of that before. The end of the wire spring has a swage fitting to attach it the last loop of the coil on both ends. That swage fitting has been known to come loose, just like swaged ripcord pins. If it does, that wire end is left free to poke around on its own and cause nefarious trouble.

[pchapman 261]

councilman24

I've had three Strong PEP's from two different riggers in different parts of the country. come through where the stuffed ALL the PC material into the CENTER bottom of the PC spring.

Huh!
I just looked at a couple Strong PEP manuals (of different ages) and see that all they really say about the pilot chute is "For ease of packing, we recommend compressing the pilot chute on a closing strap and locking with a locking rod." (And later a bit about using a fid to tuck away any excess fabric hanging out from the external PC.)

That's it. Nothing about where the fabric goes. That could be improved. Guess some riggers, not sure about what's normal in the industry, "roll it up into a ball" as they compress it., wrapping the fabric up inside. Well that sure avoids having excess fabric hanging out!....

[councilman24 36]

New manuals have fabric between the coils as you compress it.

Stand the pilot chute upright on the
locking strap. While compressing
pilot chute, neatly and symmetrically
tuck the pilot chute’s canopy cloth
in between the coils of the spring.
Continue until the pilot chute is fully
compressed and lock with locking
strap.

I'm old for my age.
Terry Urban
D-8631
FAA DPRE

[riggerrob 558]

I have only seen one swage come loose. That was ascribed to poor quality control at the factory .... er .... the final inspector missed a missed swage/squeeze/crimp.
If the end of a spring does get loose, it is less likely to snag on a hard surface .... like a kicker plate.

As for ripcords swages/pins/balls coming loose .... I have never seen it despite manufacturing hundreds of ripcords ( while working for Butler, Rigging Innovations and ParaPhernalia).
I also assembled a few hundred pilot-chutes while working for Butler.