Large ring three ring damage

[councilman24 36]

Last night I saw some damage that I've only seen once or twice 20 plus years of rigging. The RW-7 rings (mini three ring harness ring) had been worn significantly. One much more than the other! Both rings showed significant "polishing" and the inner surface had been flattened. But on one side the ring had been worn away on the front surface about 0.010" to 0.015" at 10 and 2 o'clock by the second ring. This was easily seen and I expected it to measure even more. There was a distinct "hump" at 12 o'clock where the original profile still existed.

I remember seeing this once before but it might have actually been the same rig when it was taken out of service a few years ago. (It's hell getting old.

I'd like to know how common this level of damage is? I estimate this rig has 1500 to 2000 jumps. I know the history of it and that's a fair estimate.

I assume the damage was on one side ( and right now I don't remember which side) because he always turned that direction for landing and probably higher also. But, this was a Monarch, not a particularly higher performance canopy.

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

[RiggerLee 61]

RW-7 or the heavier RW-8?

Lee

Lee
[email protected]
www.velocitysportswear.com

[councilman24 36]

RW-7, from the early 90's.

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

[AggieDave 6]

Would you be able to post some pictures showing the damage? I'm having trouble visualizing the damage to the components you described.

--"When I die, may I be surrounded by scattered chrome and burning gasoline."

[JerryBaumchen 1,082]

Hi Terry,

Do you know who the ring came from? DJ or RWS or ????

Thanks,

Jerry

[councilman24 36]

I don't have it. The owner was going to call Sunpath about a whole new harness and maybe send it out. He paid less than the value of the reserve for the whole rig so he can put some money in it.

On the front of the ring, where the middle ring on the riser touches the harness ring in two places, those places have been worn down the 0.010 to 0.015". This leaves a high point in the middle where the forward face of the ring is still intact.



View from top of ring

--------____ ____------____ ____-------- front face of ring
----- -----

--------------------------------------------------- harness side of the ring.

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

[councilman24 36]

Stamped RW-7 so I assume from RWS.

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

[Hooknswoop 19]

How close to the current RWS specs are the risers?

Derek

[riggermick 6]

Quote

I don't have it. The owner was going to call Sunpath about a whole new harness and maybe send it out. He paid less than the value of the reserve for the whole rig so he can put some money in it.

On the front of the ring, where the middle ring on the riser touches the harness ring in two places, those places have been worn down the 0.010 to 0.015". This leaves a high point in the middle where the forward face of the ring is still intact.



View from top of ring

--------____ ____------____ ____-------- front face of ring
----- -----

--------------------------------------------------- harness side of the ring.

The damage (wear) looks consistant with the middle ring contact on the base ring (if I read your diagram correctly), but I'm baffeled as to why it would occur on an offset from center and only on one ring. First question I would ask is: Are both rings from the same batch? Or were there overlapping batches used on that rig? Only the tracability paperwork would be able to sort that question out. Second question would be: Was the rig used for any other type of activity other than regular jumping, such as para sailing while being towed? Perhaps it is the result of the way the canopy is handled when being carried back from landing or packing. Either way the metal should be hardness tested to see if it was incorrectly finished.

Another place to look would be the main risers that have been with the canopy the longest, was one of the middle rings stainless steel instead of cadmium plated? Was it over tollerance (thickness) in relation to the other middle ring? Was the loop shorter on that side causing a greater pressure on the base ring? All this aside the base rings should be hardness tested against each other and the standard.

Curiouser and curiouser (Alice in wonderland).

Mick.

[mjosparky 3]

Quote

Are both rings from the same batch? Or were there overlapping batches used on that rig? Only the tracability paperwork would be able to sort that question out.

And this is probably the biggest part of TSO. Testing is only done once, tractability paperwork follows every part of every rig during manufacturing.

My idea of a fair fight is clubbing baby seals

[riggermick 6]

Quote

Quote

Are both rings from the same batch? Or were there overlapping batches used on that rig? Only the tracability paperwork would be able to sort that question out.

And this is probably the biggest part of TSO. Testing is only done once, tractability paperwork follows every part of every rig during manufacturing.

That's the FAA's main thrust during ACEP audits (every 2 years), that and toll and guage control. Gold star for that observation!!.


Mick.

[riggerrob 563]

Quote

RW-7, from the early 90's.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

What was the last year RW-7 rings were made?