Shoulder Harness Install

[n2801c]

I have a 1954 170B. Thinking about adding shoulder harness kits for the front seats. I see there are basically 2 types - the Y and the 3-point single strap. Are there STC's available for both types? Which type is most recommended? When I look in Wag-Aero or Sportys Catalogs, they appear to be out of stock. Are there other suppliers available?

[redacted]

https://basinc-aeromod.com/cessna.php

[Richgj3]

Having just gone through this, my comments

BAS are great. Put them in the Bonanza I used to have. They are the most costly. They require drilling through the top of the airplane. They come with an STC. They are inertial reel type and work very well. 337 required. Makes grabbing the first ten degrees of flaps easy!

Hooker makes a set that are also STC’d. They are not inertial reel. They cost less than BAS. They require drilling also. 337 required

WAG Aero (Aero Fabricators) has an STC. Requires drilling to add an AN4 nut and bolt in the rear carry through. 337 required.

WAG Aero sells the same FAA PMA belts individually without an STC. These belts can be installed in the factory provided AN3 nut plates in the rear carry through. This is considered a minor alteration according to my IA/DAR and confirmed by my FSDO and can be done with a log book entry. If you have the 170B IPC you can find these nut plates with their part number and the comment “shoulder harness”.

This is the way I went. Probably the most economical if you don’t need inertial reel. All are the “Y” type.

[Bruce Fenstermacher]

I wouldn't consider the 3 point myself.

Inertia reel systems are the Cats Meow. BAS is the only option for most.

I had an A with no nut plate. I used the Hooker STC to install the AN-4 nut plate. Then installed fixed y harnesses for a few weeks until I acquired a pari of AM Safe reels which I rewebbed with the Y harness and installed on with the AN-4 nut plate. The inertia reel install being legal using the FAA's guidance on shoulder harness installations of aircraft prior to their requirement. This route to inertia reels is not the best for most which is why I say BAS is the best option for them.

Having used a fixed Y harness for a short time I can say it is better than nothing and I'd encourage the installation, especially for all B models that already have the AN-3 nut plate installed.

As for availability. There are lots of shortages in aviation these days. I recently wanted to replace some brand new Aero Fabricator seat belts I'd bought for my Vagabond from Wag Aero. Wag Aero and most belts from Spruce, are Aero Fabricator Belts (Aero Fabircators is part of the Wag Aero group). I didn't know it till I bought and used Aero Fabricator belts, but what I really wanted was Davis Aviation belts and buckles. I had to put up with the Aero Fabricator belts for more than 6 months because Spruce, the only direct reseller of Davis belts I could find, had no stock.

What I learned is that if you don't go with BAS, Hooker or Davis belts, both seat lap belts, ie the left and right, are not adjustable, at least all the models of Aero Farbicator are not. Only one side is. The problem being both sides must be adjustable in order to place the Y harness centered correctly on your belly.

[thanatos767]

Hey ya'll, I really want shoulder harnesses in my 170A but both my A&P and myself are strongly against drilling holes in the airplane if at all possible. Is there a seat or floor mounted option for additional restraint?

[cessnut]

I am also generally opposed to drilling holes in my airplanes. However, I am even more opposed to the idea of planting my face in the instrument panel.

[GAHorn]

Hey ya'll, I really want shoulder harnesses in my 170A but both my A&P and myself are strongly against drilling holes in the airplane if at all possible. Is there a seat or floor mounted option for additional restraint?

Chris… since the C-170 was approved originally without shoulder harnesses….the FAA issued an opinion that ANY shoulder harness is better than NO shoulder harness…. and that as long as no structural alterations is made to the airframe… you can make any installation you want as a “minor alteration” (logbook entry only).

You could take a hemp rope and loop it thru the rear seat belts and it would be legal. In other words, if you want to …you could install shoulder harnesses and simply attach them to the rear seat belt attach points… or any other structure as long as you didn’t cut, weld, or drill holes thru primary structure.

The FAA opinion was published in: ACE 00-23.561-01 and a copy can be found in the Federal Register…OR…if you join the 170 Assoc’n you can obtain this and many other such documents in these Forums FREE at our Mx Library section: viewtopic.php?p=20#p20

[cessna170bdriver]

I put BAS harnesses in mine in 1995 just before my first foray into mountain flying enroute to the 170 Convention in Kalispell, MT, and I’ve never regretted it. As I recall, (on the B-model at least) there aren’t really any new holes in the airplane; just two rivets in the flange of the spar carry-through hat section replaced with high-strength screws for each inertia reel. A third screw utilizes a factory-installed nut plate in the spar carry-through.

[dstates]

I added BAS shoulder harnesses in my A model. We did have to add the nutplate. Here is a thread with some good discussion and pictures of the nutplates I installed towards the end. I'm super happy with the install.

viewtopic.php?t=15534

[thanatos767]

Thanks ya'll, I appreciate the help!