Shoulder Harness & Belts

GAdams · #1 07-24-20, 11:55 AM

I'm trying to install Hooker Shoulder Harness and Belts in my 337D. Unless I want to get a DER involved at great expense it can't be done legally. I know the BAS system can be installed and Cessna has a kit for a single shoulder harness. SK337-55A2, which is available from Cessna. I'm going with the Cessna kit unless anyone has any ideas about the Hookers I already own.

Skymaster337B · #2 07-24-20, 05:19 PM

I installed the Cessna kit on my B model. The kit included new shoulder and lap belts, for the front two seats, and the hardware to install it. My plane already had the threaded Holes for attachment in the airframe. It was easy to install. Well worth it...if you ever need it.

JAG · #3 07-25-20, 11:36 AM

I am a BAS guy, installed in both of my aircraft. I like the 4 point system for safety, and they are comfortable to fly with. Can also undo the should harness in flight if you want. A little more work to install than Cessna (I believe), but not difficult to do over a weekend.
Jeff

hharney · #4 07-26-20, 10:38 AM

I have the BAS system and am very happy I took the time to install it when I did a refurb on the interior. I considered the Cessna kit but really glad I pursued the four point harness. I was concerned that they wouldn’t be comfortable in flight but I have never had to take them off for any flight. You could remove the uppers during flight but you won’t need too. Hooker Harness makes great belt system but I’m not doing aerobatics in my Skymaster. There is some talk about the concern of drilling through the forward spar for attachment but I think it is a proven system and am not concerned about the install. Go with the best system out there and for us it’s BAS. Protection is the best reason.

wslade2 · #5 08-02-20, 11:16 AM

are there any shoulder belt systems for the rear occupants?

JimC · #6 08-04-20, 11:48 AM

The middle seats can get shoulder harnesses form serial number 1194 onward. The rear seats can get them from serial number 1317 onward.

My parts manual shows that the middle seats take the same shoulder belt assembly as the pilot & copilot. The rear seats take a different one. The part number varies with color.

I'm considering the 3-point airbag system from Amsafe instead of the 4-point BAS system (which is really a 3-point with a split shoulder harness.)

wslade2 · #7 08-04-20, 10:37 PM

awesome. I'm in the serial number range. Looks like I take it just need to buy the parts/belts for the middle seats (the ones I want to do) and install. As you say, same belts as for pilot and copilot. Anchor hole for shoulder harness already installed at factory? (I'll be looking next time I go out)

JimC · #8 08-05-20, 10:43 AM

It looks like that to me, and others have reported finding mounting attach points under the headliner.

I can't upload the manual (too large) but send me a PM and I'll send you a PDF with the relevant pages & part numbers.

hayesjaj · #9 08-08-20, 10:55 AM

Can confirm the mounting holes on my 337G (1535). My interior is out right now and I can take pictures of the mounting holes tomorrow if you’d like. I plan to install BAS in the front, something with inertial reel in the middle and the straight cessna kit in the rear.

JAG · #10 08-09-20, 09:48 AM

After installing my BAS in the front, I moved the front belts (cessna 3 point harness) to the second row and it fit almost perfect!

CO_Skymaster · #11 02-14-23, 12:51 AM

@JimC

Did you follow up on your purchase for the AMSafe 3-point harness. My aircraft is a Cessna 337A around 400 for the serial number, so from reading some of these posts it will only have the 3-point harness for the pilot and copilot.

Karl

JimC · #12 02-14-23, 11:31 AM

I installed the 4-point BAS system in my SkyMaster and it worked fine. I would change to the rotary buckle instead of the 4-piece attachment. The 4-piece is mechanically simpler, but is harder for passengers to figure out.

I've also installed the AmSafe airbags in another plane and I like them. They come with a shoulder reel but it is NOT required for the airbags to be legal, functional and safe - you can install the lap belt & airbag without the shoulder reel. If you're looking for extra safety for the rear seats this is what I'd recommend. Installation was fairly straightforward (I did it myself with an A&P signoff.) Disconnection is easy if you want to remove the seats for any reason.

CO_Skymaster · #13 02-14-23, 11:40 PM

Thanks for the answer JimC. I wanted to install 3 points, at least in the front seats. I found a person at Amsafe for my mechanic to talk to about the installation.

Karl

CO_Skymaster · #14 02-23-23, 01:13 AM

@JimC

Hi Jim, I have another question for you or anyone else that has a Cessna 337A. I talked to my mechanic about installing the AMSafe 3 point seat belts and he took a look and found there was not a hard point to attach the shoulder harness to without major modifications. He was suspecting he might have to attach to the wing spar. Did your Bas 4-point seat belts require attachment to the wing spar or some other type of major modification? Or did they find another less intrusive way to attach? Was your Bass 4-point seat belt installation STC'ed?

Karl

JimC · #15 02-23-23, 09:04 AM

The BAS installation was STC'ed, and the attachment point was directly behind the pilot's head. We did not drill a hole in the spar, but I don't have more details than that. Remember, the BAS isn't a true 4-point. It has 3 points of attachment on the airframe and 4 points at the main buckle. The dual shoulder straps attach at a single point behind the pilot's head, split to go around the pilot's neck, and then two buckles attach at the center of the pilot's waist.

One nice feature of the AmSafe belts is that the 3rd shoulder harness is not required. Certainly we want it, but it's not a legal necessity. You can install the lap belt & airbag and fly safer than you were before while you wait on engineers and paperwork to determine how you will add the shoulder belt. The shoulder belt needs to cross the pilot's body diagonally, so the attachment point directly behind the pilot's head won't be appropriate.