Shoulder harness - legal question

lk · Post by lk » Wed Oct 17, 2007 10:41 pm

If the plane didn't originally have shoulder harnesses, but has since been fitted with them, is it permitted to remove them and fly without, using just the seat belts? The seat belts are fine, the harnesses need repair. Is it strictly legal to fly without them?

Post by **Bruce Fenstermacher** » Thu Oct 18, 2007 1:02 am

Yes you can remove them under most circumstances unless they are an integral part of the lower belt system some how. Most are not.

But to be perfectly honest why not have them repaired and use them which is what I suggest. They will save your butt (head) if you have an accident.

Post by **GAHorn** » Thu Oct 18, 2007 2:42 am

The pilot is permitted to remove/replace seatbelt/harness assemblies under the "preventive maintenance" rule. But if your harness was installed by an STC or other approved method and logged onto the aircraft (and therefore should be included on the equipment list) it will be necessary to have an authorized person (A&P/IA) log them back off the aircraft if you intend to remove them permanently.
They can probably be repaired/rebuilt by Aircraft Belts, Inc. (EDIT: AIRCRAFT BELTS HAS BEEN PURCHASED BY ANOTHER COMPANY. THE INFO BELOW MAY NO LONGER BE CURRENT.)

Aircraft Belts, Inc. (ABI)
2000 Anders Ln.
Kemah, TX 77565
Phone:
Fax: 281-538-4747
Tollfree: 800-847-5651
E-mail:info@airbelts.com
Website: http://www.aircraftbelts.com

http://www.aircraftbelts.com/contact.html

AGB · Post by **AGB** » Thu Oct 18, 2007 1:20 pm

Hello,
The NTSB has a Safety Report - General Aviation Crashworthiness NTSB/SR-83/01. One of the conclusions of the report is that Shoulder Harness reduces in 20% fatal injuries and in 80% serious injuries.

In my opinion Shoulder Harness is a wordy investment in ones own safety.

Regards,
Donovan

Post by **GAHorn** » Thu Oct 18, 2007 2:18 pm

Good words, Donovan!

Also, keep in mind that you don't have to purchase TSO'd or STC'd shoulder harnesses for a Cessna 170 (and many other aircraft.)
You can also create your own using simpler, non-TSO'd methods. See the FAA position letter on this matter at: http://www.cessna170.org/forums/viewtopic.php?f=5&t=8

For $51 each you can buy the simple Davis Shoulder Harness and install it to use with your regular lap belts. If you have a B-model, your rear spar already has the attachment point built-in.
http://aircraftspruce.com/catalog/appages/harness3a.php

Harness with stitched-in webbing loops for use with any 2" wide seat belt. Belt simply slides through loops and secures. Harness is "Y" type with one attachment fitting furnished.

Paul-WI · Post by **Paul-WI** » Thu Oct 18, 2007 4:27 pm

For $51 each you can buy the simple Davis Shoulder Harness and install it to use with your regular lap belts. If you have a B-model, your rear spar already has the attachment point built-in.
http://aircraftspruce.com/catalog/appages/harness3a.php

Is anyone using this harness? I want to put in a shoulder harness this fall. I would like to put in the BAS system, but the funds don't allow it yet. I thinking this maybe a cheaper alternative. Only drawback I see is possibly reaching for the flap handle - although with my long arms I don't think it will be a problem. Comments????

Paul

jrenwick · Post by **jrenwick** » Thu Oct 18, 2007 5:05 pm

Paul,

I have Hooker harnesses in my 170 (http://www.hookerharness.com/aviationstckits.php). They don't have inertia reels. When the harness is snug I can't quite reach the flap handle button with my hand, but I can hook it with my right foot. Once the button is pushed that way, I can raise the lever by hand. I'm now so used to doing this, I don't consider it to be any problem.

n3833v · Post by **n3833v** » Thu Oct 18, 2007 5:52 pm

I have no retractible harness and set it for panel clearance and can easily reach the flap handle.

John

cessna170bdriver · Post by **cessna170bdriver** » Thu Oct 18, 2007 6:16 pm

I have the BAS intertial reel belts in my '55B and like them very much. Then again I paid big $$$ for them, so I might be a bit biased.

Besides being able to reach the flap handle (that is THE reason I got inertial reels), I like the fact that there is an additional attach point through the roof in addition to the one that was already in the rear spar carry-through. Maybe not necessary, but gives me a warm fuzzy.

Here's another thread that might have some useful info on belts/harnesses.

http://cessna170.org/phpBB2/viewtopic.php?t=2875

Miles

Post by **GAHorn** » Thu Oct 18, 2007 8:36 pm

Paul-WI wrote:
For $51 each you can buy the simple Davis Shoulder Harness and install it to use with your regular lap belts. If you have a B-model, your rear spar already has the attachment point built-in.
http://aircraftspruce.com/catalog/appages/harness3a.php

Is anyone using this harness? I want to put in a shoulder harness this fall. I would like to put in the BAS system, but the funds don't allow it yet. I thinking this maybe a cheaper alternative. Only drawback I see is possibly reaching for the flap handle - although with my long arms I don't think it will be a problem. Comments????

Paul

Paul, it's what I have in my plane.
I originally did it as a cheap method of getting a shldr harness, thinking I"d later upgrade to something else. It's so plain simple and easy to use, I've kept it. I plan to submit them to Aircraft Belts to have them re-web them to color match my others. I adjust them so they're short enough to keep my face off the panel, but loose enough to allow comfort and reach the flap handle. 5 years of happiness with them. Cheap.

Simple installation: Unzip headliner to locate the factory-equipped rivnut, poke small hole thru headliner, install triangular end-fitting (supplied with harness) with stainless MS screw, one large, one small SS flat washer and steel bushing, zip the headliner closed, slip the lap belts thru the loops, and go fly.

The large SS flat (fender) washer is above the end-fitting to prevent chafeing the headliner and to hold the headliner firmly up against the rear spar, the small SS flat washer is to provide a bearing surface for the head of the #10 MS27039C (Stainless Steel) screw (spruce part number MS27039-1-14 I think), and the bushing (to properly fill the hole in the end fitting and long enough to provide something for the screw to bottom out on and allow free-swivel to the end-fitting) I made from 1/4" steel tubing by cutting it with a tubing cutter. You could also use a NAS600 or NAS603 screw if you didn't insist on stainless.

You'll need two of everything, of course.
Be careful of which screw or bolt (AN3 would work) you choose. Don't choose a non-structural 55,000 psi screw. Choose a 125,000-180,000 psi screw (with a short shank to accomodate the bushing) such as one of those I've suggested.

Paul-WI · Post by **Paul-WI** » Thu Oct 18, 2007 9:24 pm

Thanks. I think that is the route I will take. I see that I will have the same mix of colors as you for seat belts - oooohh. This does look like a good and cheap alternative. I just don't like flying without shoulder harnesses - although I never plan on using them, it sure is nice to have that extra margin of safety so I don't face plant my face into the instrument panel (although it may improve my looks).

Paul

jrenwick · Post by **jrenwick** » Thu Oct 18, 2007 9:59 pm

Some of the harness manufacturers (Hooker, for one) will warn you that the factory-installed rivnut in the rear spar carry-through isn't enough of a support for shoulder harnesses, and may let go in the event of a crash.

It's certainly better than no harness at all, though.

Post by **GAHorn** » Thu Oct 18, 2007 10:24 pm

jrenwick wrote:Some of the harness manufacturers (Hooker, for one) will warn you that the factory-installed rivnut in the rear spar carry-through isn't enough of a support for shoulder harnesses, and may let go in the event of a crash.

It's certainly better than no harness at all, though.

It never hurts to promote one's product over another's.

The factory rivnut is installed interior (per the same 9-G spec as Hooker's) to the hat-section of that rear spar. The angle at which it is strained places it in shear, on top of that. By the time you pull that thru the floor of the spar (or shear a 125,000 psi screw) your shoulders have been ripped off and your spine crushed anyway.
There are no records of that factory rivnut failing that I'm aware of, but the Hooker method certainly appears more robust (albeit a lot more work. And the finished product requires a larger slit..unsightly in my opinion...in the headliner.)

Post by **GAHorn** » Thu Oct 18, 2007 10:43 pm

Donovan (and others) be aware that FAA Policy Statement Number ACEâ€“00â€“23.561â€“ 01 which I referred to at http://www.cessna170.org/forums/viewtopic.php?f=26&t=8 is very specific that no alterations, cutting, welding, to primary structure is allowed if the owner/pilot desires to install a non-TSO'd shoulder harness such as I have illustrated in my airplane.

There are numerous ways to accomplish installations that do not involve structural modification to the aircraft, including but not restricted to cables/clamps. So if you do not have a Cessna 170-B or early Cessna 172, there are alternatives for you. (Pipers and Stinsons use common aircraft cable clamped to itself after wrapped around steel tubing overhead.)

Some systems use the rear seat belts looped thru the shldr harness for the front seats. Anything is better than nothing.

Fri Oct 19, 2007 12:36 am

George I want to point out that the picture you had in your last post of the belt attachment also showing the cables is of the Hooker installation. Took me a bit to figure out what is was you where showing.

I also want to point out that, at least in my case, these are not rivnuts in the carry through spar but a nut plate riveted on the inside of the carry through spar. You would either have to shear the AN-3 bolt or pull the nut plate through the spar before it failed and as George points out at that point you might be glad it failed to finish the job.