USA Riggers: Does 22-lb limit include the seal/thread?

[Unstable 8]

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Seems like opinions differ on the subject

I think it's irrelevant. If there is slack on the seal thread, even a little, the peak force will occur at the moment the pin starts to m over, at which point dynamic friction takes over and the force required to continue the extraction will be significantly less.

I know very few riggers (actually, none) that do the pull test to full extraction - they know that once the pin budges, that is max. If there is even a bit of slack on the thread, the tension will be applied during motion, and would not touch the 22-pound limit.

That is my hypothesis - obviously a fixture to test this reliably would be needed, something that would both apply and measure perfectly throughout the entire motion.

=========Shaun ==========

[fcajump 153]

Unstable

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Seems like opinions differ on the subject

I think it's irrelevant. If there is slack on the seal thread, even a little, the peak force will occur at the moment the pin starts to move..., at which point dynamic friction takes over and the force required to continue the extraction will be significantly less.

I know very few riggers (actually, none) that do the pull test to full extraction - they know that once the pin budges, that is max. If there is even a bit of slack on the thread, the tension will be applied during motion, and would not touch the 22-pound limit.

That is my hypothesis - obviously a fixture to test this reliably would be needed, something that would both apply and measure perfectly throughout the entire motion.

Logging: On the BACK side of the repack cycle, I know many that do pull tests to extraction when starting an inspection. While that does NOT indicate what the force would have been on day 1, it is likely that on day 1 it was no less (exceptions for Racer and Reflex).

Peak force: I have noted in my own testing, and listened to a furious discussion by one rigger attending PIA Symp (2013 or maybe 2011) that if one draws the pin (very) slowly (contrary to actual use or TSO testing procedures) many pins have a second (sometimes higher) peak force while moving just prior to the tip clearing the crown of the far side of the grommet. Once noting that, I started testing with a more decisive pull rather than slowly creeping it out. The individual I was listening to was an advocate of routinely changing the grommets to ensure there is absolutely NO scratches/burs/etc on the grommet surface to minimize the pull force as a result of this slow-pull peek observation.

JW

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

[Unstable 8]

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Peak force: I have noted in my own testing, and listened to a furious discussion by one rigger attending PIA Symp (2013 or maybe 2011) that if one draws the pin (very) slowly (contrary to actual use or TSO testing procedures) many pins have a second (sometimes higher) peak force while moving just prior to the tip clearing the crown of the far side of the grommet. Once noting that, I started testing with a more decisive pull rather than slowly creeping it out. The individual I was listening to was an advocate of routinely changing the grommets to ensure there is absolutely NO scratches/burs/etc on the grommet surface to minimize the pull force as a result of this slow-pull peek observation.

INTERESTING! I have the bits and pieces to test this, and it may become my weekend project.

***Edited to Add***

SAE AS9015A/B makes many reference to the test being done under normal conditions for use - I haven't measured pull force to the tip on a slow pull, but I would struggle to believe in the relevancy of that datapoint.

In regards to the individual at PIA, I am even more skeptical. Can he/she provide any data showing this phenomenon and then using a good test methodology, show causation to the condition of the grommets? I don't mean to argue in the face of those with more experience than I, but in this case, I would want to see the data.

=========Shaun ==========

[councilman24 36]

Unstable

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Peak force: I have noted in my own testing, and listened to a furious discussion by one rigger attending PIA Symp (2013 or maybe 2011) that if one draws the pin (very) slowly (contrary to actual use or TSO testing procedures) many pins have a second (sometimes higher) peak force while moving just prior to the tip clearing the crown of the far side of the grommet. Once noting that, I started testing with a more decisive pull rather than slowly creeping it out. The individual I was listening to was an advocate of routinely changing the grommets to ensure there is absolutely NO scratches/burs/etc on the grommet surface to minimize the pull force as a result of this slow-pull peek observation.

INTERESTING! I have the bits and pieces to test this, and it may become my weekend project.

***Edited to Add***

SAE AS9015A/B makes many reference to the test being done under normal conditions for use - I haven't measured pull force to the tip on a slow pull, but I would struggle to believe in the relevancy of that datapoint.

In regards to the individual at PIA, I am even more skeptical. Can he/she provide any data showing this phenomenon and then using a good test methodology, show causation to the condition of the grommets? I don't mean to argue in the face of those with more experience than I, but in this case, I would want to see the data.

This persons answer to high pull forces resulting from edging the pin out slowly was not only to routine replace grommets that had normal or little wear but to put in VERY long closing loops. As I understand it he pulled the pin as slow as he could looking for the absolute highest pull force he could get. Higher than 22lbs the rigger got new grommets and longer loops. I was asked by other riggers local to his area to try to explain to this rigger why long loops could be fatal. I don't think he listened. He was NOT a speaker at the symposium. This guy did not have the sense of a rock.

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

[masterrigger1 2]

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Please quote chapter and verse, if you are able.

Mr. Sellars can have that conversation with you again if you like.

MEL

Skyworks Parachute Service, LLC
www.Skyworksparachuteservice.com

[mark 102]

masterrigger1

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Please quote chapter and verse, if you are able.

Mr. Sellars can have that conversation with you again if you like.

MEL

In other words, you are unable to cite the regulation and unable to cite the preamble. I don't recall that Jude did either. What we agreed was that expecting a seal (during a ramp check, for example) was common practice, one that most riggers were okay with, and one that might be a good idea, but that it was unsupported by regulation.

Mark

[fcajump 153]

councilman24

This persons answer to high pull forces resulting from edging the pin out slowly was not only to routine replace grommets that had normal or little wear but to put in VERY long closing loops. As I understand it he pulled the pin as slow as he could looking for the absolute highest pull force he could get. Higher than 22lbs the rigger got new grommets and longer loops. I was asked by other riggers local to his area to try to explain to this rigger why long loops could be fatal. I don't think he listened. He was NOT a speaker at the symposium. This guy did not have the sense of a rock.

Terry - thanks. I was only a hanger-on to the discussion and did not have a complete picture...

Terry's correct that the individual was not a PIA speaker, simply a rigger with a question/issue/point-of-view whose peers were seeking (it seemed to me) an intervention... sorry if that was unclear in my prior post.

JW

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

[Unstable 8]

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This persons answer to high pull forces resulting from edging the pin out slowly was not only to routine replace grommets that had normal or little wear but to put in VERY long closing loops. As I understand it he pulled the pin as slow as he could looking for the absolute highest pull force he could get. Higher than 22lbs the rigger got new grommets and longer loops. I was asked by other riggers local to his area to try to explain to this rigger why long loops could be fatal. I don't think he listened. He was NOT a speaker at the symposium. This guy did not have the sense of a rock.

That sounds like a terrible approach. I don't know where to start. I can't even....

a. The approach you explained confounds the loop length and grommet effect.

b. Pulling as slow as possible is not representative of expected use in any way, shape or form

c. If he/she is pulling by hand and measuring, I highly doubt the force applied to the ripcord is even - you'll be measuring the affect cause by both acceleration and jerk.

d. Moving 'as slowly as possible' is going to be pushing right at the breaking point between static and dynamic friction. How do we know that the person performing the test didn't just slow down the pull as he approached the tip of the pin, perhaps in expectation of the reserve popping?

e. Detrimental effects to the container by frequent grommet replacements? We know the spur grommets bite and deform the material.

f. Long loops? I can't even on this one.

Was this guy a Master rigger? If so, then maybe that gives me hope for passing my own MR exam. I spend my days as a Statistician - all day everyday people bring me theories that just magically go away when I ask for the data. It's a great trick.

=========Shaun ==========

[councilman24 36]

mark

***

Quote

Please quote chapter and verse, if you are able.

Mr. Sellars can have that conversation with you again if you like.

MEL

In other words, you are unable to cite the regulation and unable to cite the preamble. I don't recall that Jude did either. What we agreed was that expecting a seal (during a ramp check, for example) was common practice, one that most riggers were okay with, and one that might be a good idea, but that it was unsupported by regulation.

Mark

Expecting a seal common is not just common practice, Inspectors are directed to ensure it is there.

Chapter and verse, one example. emphasis added

FAA Order 8900.1

1-1 PURPOSE. This order directs the activities of aviation safety inspectors (ASI) responsible for the certification, technical administration, and surveillance of air carriers, certain other air operators conducting operations in accordance with the appropriate part of Title 14 of the Code of Federal Regulations (14 CFR), certificated airmen, and other aviation activities. This order also provides direction for tasks related to aircraft accidents and incidents, investigations and compliance, the aviation safety program, administrative areas, and miscellaneous tasks not related to a specific regulation. In addition, it contains regional and district office requirements for the support of ASIs responsible for those activities.

Volume 6 Surveillance
Chapter 11 Other Surveillance
Section 11 Monitor an Air Show/Air Race for Airworthiness Inspectors
6-2413 PROCEDURES.
D. Inspect Parachutists’ Equipment. Inspect parachutists’ equipment to ensure the following:
· The main parachute has been packed within the previous 180 days;
· The equipment has been manufactured under a TC or Technical Standard Order (TSO), or is a personnel-carrying military parachute;
· The auxiliary parachute has been packed by a certificated person within the time requirements prescribed by part 105, § 105.43;
· The certificated parachute rigger’s seal has been installed properly; and
· The parachute packs and harness are in good condition.

Your going to say this isn't regulation but specifics of this nature will never be in the CFR. As you know this order contains how the FAA inspects us as DPRE's also.

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

[Hooknswoop 19]

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D. Inspect Parachutists’ Equipment. Inspect parachutists’ equipment to ensure the following:
· The main parachute has been packed within the previous 180 days;

And how exactly would they do this?

Derek V

[mark 102]

The current version of 8900.1:

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Vol 6, Ch 11, Sec 5: Surveillance of Sport Parachute Activities
6-2251 Procedures
A.3 Parachute Harness and Container.
· Sport parachute harness and reserve parachutes (verify these are labeled per a TSO-C23 specification).
· TSO parachute pack date (refer to part 105, § 105.43(b)(1) and (2)).

Quote

Vol 6, Ch 11, Sec 10, Surveillance of an Aviation Event:
H. Inspect Parachutists’ Equipment.
Inspect parachutists’ equipment for the following:
. . .
2) Determine that the auxiliary parachute was packed and sealed by a certificated and appropriately rated rigger (§ 105.43(b) and 14 CFR part 65, subpart F).

No mention in Section 5 of a seal for skydiving. I am hopeful that we'll be able to resolve the difference at the next revision.

Note there is no requirement to write the seal on the packing data card. If the seal is not written on the data card, it is possible to see if the rig has been repacked within the past 180 days, and that it is currently sealed, but not that the seal corresponds with the rigger (unless you search the FAA's database).

Mark

[masterrigger1 2]

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In other words, you are unable to cite the regulation and unable to cite the preamble. I don't recall that Jude did either. What we agreed was that expecting a seal (during a ramp check, for example) was common practice, one that most riggers were okay with, and one that might be a good idea, but that it was unsupported by regulation.

No..it is not in other words...

It is in the preamble to 65.133.
Every rule has a preamble to describe why that particular rule is being added/written to the regulations.

It was brought up during the paper seal saga that was put to bed, so you should be already aware of that.

MEL

Skyworks Parachute Service, LLC
www.Skyworksparachuteservice.com

[mark 102]

masterrigger1

It is in the preamble to 65.133.

You are such a kidder!

As you know, 65.133 was adopted without a preamble when the CAA became the FAA and CAR Part 25.83 became FAR Part 65.133 in the early 60's.

Mark

[JerryBaumchen 1,061]

Hi Jim,

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But is that with or without the required seal/thread in place?

As any attorney will tell you, "That depends."

Here is what the various TSO's say:

TSO C23(b) / NAS 804

There is no mention of this issue in this document.

TSO C23(c) / AS8015A

Section 4.3.2.1 Human Factors

"The ripcord or equivalent shall be sealed for these tests."

Secion 4.3.2.2 Pull Test

There is no mention of this issue. Since it was specifically mentioned in the previous section, I would surmise that it does not have to be sealed for these tests. These tests ( Pull Test ) is the test for measuring the pull forces.

TSO C23(d) / AS8015B

Section 4.3.2 Human Factors and Actuation Force Tests:

There is no mention of this isssue.

Section 4.3.2.1 Primary Actuation Device/Ripcord, Human Factors Tests:

"The ripcord, or equivalent, shall be sealed in accorfdance with FAR 65.133 for these tests."

TSO C23(f) / PIA TS 135

Section 4.3.2 HUMAN FACTORS AND ACTUATION FORCE TESTS:

"NOTE: For these tests, the primary actuation device (ripcord or equivalent) shall be equipped with a tamper-indicating device (i.e. seal thread or equivalent) of the same type that will be required for production articles in service."

It seems to me that only TSO C23(f) actually requires the seal thread in place during this pull force testing.

YMMV

Jerry Baumchen

[fcajump 153]

Fair enough... that clears (as much as can be) what is said about the original question.

But expanding the thought a little... (strictly for the sake of argument) where does it say that a rigger is held to the standard of 22-lbs (or any specific pull force) if the manufacturer's manual does not specifically state it in their packing instructions?

I do see that the manufacturers are required to prove that it can be (i.e. it was TSO'ed)....

JW

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

[masterrigger1 2]

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You are such a kidder! Wink

As you know, 65.133 was adopted without a preamble when the CAA became the FAA and CAR Part 25.83 became FAR Part 65.133 in the early 60's.

Yep!
...and since 25.83 did not exist when the CAA first established the rules in 1937, they had to write a preamble to include 25.83.

Keep looking , you will find it!

MEL

Skyworks Parachute Service, LLC
www.Skyworksparachuteservice.com

[mark 102]

Nope, not in the incomplete portion of CAR Part 25 you posted -- which doesn't mention sealing at all.

To recap:
Not in the current Part 65.
Not in any preamble to any change to Part 65.
Not in CAR Part 25.

Might be in a preamble to change to CAR Part 25. Might not be. If you can't post it, or even quote it, and the best you can do is move the goalposts, I'm inclined to believe it doesn't exist.

Mark

[masterrigger1 2]

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Nope, not in the incomplete portion of CAR Part 25 you posted -- which doesn't mention sealing at all.

The regulations that I post WAS complete.All five pages of it.

If you re-read my post, you will note that I stated that since 25.83 did not exist in the CARs in 1937, they had to add the rule later which would mean that a preamble was written specifically for that rule.

You are right, I do not have it in my procession, but AFS-300 quoted from it on the paper seal saga. So it does exist.....

Quote

Might be in a preamble to change to CAR Part 25. Might not be. If you can't post it, or even quote it, and the best you can do is move the goalposts, I'm inclined to believe it doesn't exist.

Moving goalposts are your specialty, not mine.

MEL

Skyworks Parachute Service, LLC
www.Skyworksparachuteservice.com

[mark 102]

masterrigger1

You are right, I do not have it in my procession, but AFS-300 quoted from it on the paper seal saga. So it does exist.....

What was the quote AFS-300 made, exactly? Is it from the attached letter?

Mark

[mark 102]

masterrigger1

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You are such a kidder!

As you know, 65.133 was adopted without a preamble when the CAA became the FAA and CAR Part 25.83 became FAR Part 65.133 in the early 60's.

Yep!
...and since 25.83 did not exist when the CAA first established the rules in 1937, they had to write a preamble to include 25.83.

Keep looking , you will find it!

MEL

I found it!

I found CAR Part 25 when 25.83 was adopted, including the preamble and the NPRM, plus the rule before 25.83 was adopted.

The history supports my position.

Mark