Shoulder Harnesses

[T-Rex]

I am installing hooker lap belts and shoulder harnesses in T-Rex and am wondering where most of you loop the webbing for the shoulder harness. I have been told the first station aft the rear spar carry through, so this would mean the back of the extended baggage area. Does this sound correct to you all?
Thanks, Brad

[ericvap]

Re: Shoulder Harnesses

that sounds at about the same place as auto style singel sholder belt the was factory installed in my 82 f-21 I can post a photo if needed.

[Larry Lyons]

Re: Shoulder Harnesses

Do a search here of shoulder harness or Hooker and you will find photos and various options. There has been a lot of discussion on this.
Larry

[T-Rex]

Re: Shoulder Harnesses

Thanks guys, looks like I will loop them over the cross tube at the rear of the baggage.
Abbagodaa, Brad

[paulnuss]

Re: Shoulder Harnesses

The shoulder harnesses should attach above your shoulders. If below, and you ever need them, and go hard against the harness, the force will be strongly downwards on you, and you may suffer compression fractures of the spine, and spend the rest of your life badly debilitated. IF I understand where you are thinking of attaching, on the cross tube that supports the aft of the baggage sling, please consider the dangers.

[N96337]

Re: Shoulder Harnesses

Take a look at AC43.13-2A, chapter 9. It deals with shoulder harness installations and is approved data. The only reference they make to the compression loads are to keep the angle of the double over the shoulder type harness from a -5 degrees below the shoulders, to a max of +30 degrees above..... on a single over the shoulder harness, they recommend from level to + 30 degrees. If you're attaching to the floor, or seat, they recommend that the seat back be as high as the person's shoulders (section 163, 162 b.).
John

[paulnuss]

Re: Shoulder Harnesses

With all due respect to AC43.13-2A Chapter 9, and its approved data, I remain steadfast in my recommendation that the shoulder harness mounting should be higher than one's shoulders, to avoid any compression when/if the belts ever are needed in a crash. This was a factor in relocating belts in my Pitts; I am taller than the factory mounting points, and I had to come up with something different. The newer Pitts S2's also did something different than my 1974 model, for that very reason.

[flyguy]

Re: Shoulder Harnesses

And again I will beat the drum on the desirability of fastening the harness to a triangulated point vs in the middle of a tube. Reason: the first fraction of an inch that the middle of a tube moves, when pulled on, puts a huge stress on the welds at the ends. If the weld attach point is very sturdy and does not flex inward the weld can break. I have seen it in a crash of a tow plane.
DC

[T-Rex]

Re: Shoulder Harnesses

Thanks for all of the input guys. I attached my harnesses at the outer points of the upper cross tube at the rear of the extended baggage (f-19) area. AC23-17B has a lot of really good info and was the basis for my field approval. We also used the info in 43.13.

[jim34285]

Re: Shoulder Harnesses

Do a search here of shoulder harness or Hooker and you will find photos and various options. There has been a lot of discussion on this.
Larry

Larry, Where can I search to get this information?

Jim

[Larry Lyons]

Re: Shoulder Harnesses

Look in the blue bar at the top of this page, click on the word "Search", fill in the box with your request and click on GO! Try a couple of different words to get better/more results.
Larry

[astjp2]

Re: Shoulder Harnesses

43.13 is not approved data, its acceptable data, there is a difference....

[N96337]

Re: Shoulder Harnesses

43.13 is not approved data, its acceptable data, there is a difference....

Yep...my mistake in wording... it is Acceptable....not approved. Good point!
John

[NY86]

Re: Shoulder Harnesses

43.13 is not approved data, its acceptable data, there is a difference....

You guys are missing out on a lot...

Read the page immediately preceeding the contents of AC43.13-1B (page ii?), particularly paragraph 1 "Purpose".

I'll paraphrase: "...The repair data may also be used as approved data...when:

a. the user has determined that is it appropriate to the product being repaired;

b. it is directly applicable to the repair being made; and

c. it is not contrary to manufacturer's data."

[N96337]

Re: Shoulder Harnesses

Thanks John....I could've sworn I'd heard something like that at an IA seminar, but couldn't find it anywhere...... the mind is the second thing to go?
John