Shoulder Harnesses

[N96337]

Re: Shoulder Harnesses

Look at AC43.13-2A...there's a section about shoulder harness installs. You don't want them right above your shoulders... they recommend a max of 30 degrees above horizontal....
JH

[astjp2]

Re: Shoulder Harnesses

The rear spar compression tube is probably the best location to install the shoulder harnesses, you could make a metal 1"X1/8" strap to go around the tube and attach them to it. That is what I am planning on doing when I install mine. Tim

[Forrest Barber]

Re: Shoulder Harnesses

Prior to easing the installations to a log book entry we had to use the Feris system on the F-19's and up. here are two diagonal gussets welded in back at the top of the fuselage one bay back of that cross tube at the rear spar,( station 5) then a cable shackle on each side leads to a 1/8th cable and on to the safety harness, the F-19 used only one cross over strap for each occupant.

That was the part# 2683-1 (2) cable ass'm &
# 2684-1 (2) strap ass'm from cable to seat belt ; these are noted in the parts book page12.

I have used a catinary system that allowed the double harness to both occupants.

[flyguy]

Re: Shoulder Harnesses

As I have seen the results of the impact of a tow plane on a dike wall I have a real appreciation for the forces involved. The thing I got from it, and mentioned here before, was: don't put a seat belt attachment in the middle of a cross bar that is not triangulated to the rear. Putting a forward load on the middle of a tube applies an almost infinite load on the welds at the end as it flexes the first fraction of an inch forward.
But then a few folks here said that wasn't so. Ah, well.

My solution with the "back board" is far from excellent, but at least it would be a big improvement over what I have now.
And yes, not withstanding what I say above, a mount in the middle of a horizontal tube is a considerable improvement over no shoulder harness at all, but you should expect that it will pop the welds at he ends before the harness itself breaks.
DC
Edit: Yep Forrest, that is the strongest and best method and location that I have considered in the past. Is there a drawing we can get that shows the details of the cable routing? I wasn't sure about the best way to do that.