Jr.CubBuilder wrote: I do miss being able to cinch the shoulder down in turbulence though.

I've been thinking about that too. Originally i thought the BAS (which I don't own yet) wouldn't allow a firmer feel in turb, but I realized that any secure sinching down in turbulence is going to occur with the lap belt, which is not on an inertial reel.

If you're bouncing fore and aft in turbulence, you're in a little different turbulence than I'm used to .

The seat belts should keep you in your seat.

The military harnesses I've used were designed to lock because (at least the ones I used--not many, by the way) weren't self locking (in other words they weren't inertially locking) harnesses. The only way those locked up was if you locked them.

In any case, those diagonal one belt across the shoulder belts are worthless also, in my opinion. The body gets pretty fluid when there's a lot of inertia.

MTV

mtv wrote:The military harnesses I've used were designed to lock because (at least the ones I used--not many, by the way) weren't self locking (in other words they weren't inertially locking) harnesses. The only way those locked up was if you locked them.
MTV

All of the ones that I'm familiar with are either or, that is they will always lock on inertia, you can't turn that off, but if you want to you can manually lock them. "Shoulder harnesses - lock" was in most emergency landing checklists.
USAARL, United States Army Aeromedical Research Lab tests pretty much determined that a four point harness wasn't much if any better than a three point because you submarine a four point so easily. Apparently in a crash sequence the seat either deforms or at least the cushions squash and your body shoots out underneath the seat belt. With a five point harness this doesn't happen. It doesn't help us of course, but the greatest safety thing in the newer helicopters is a seat that "strokes", that is it collapses in a controlled manner, gradually decelerating the crew member and absorbing energy as it does.
Like it or not a properly designed helmet is at least as important as stroking seats and five point harnesses too.
Oh, and another thing I thought was interesting. With the crash dummies USAARL found that something they called "rebound overshoot" was a killer. What that is, is if you tighten your shoulder harnesses to the point your back is bent over, during the crash sequence it is likely that your body will be thrown back against the straps when you rebound and this can break your back, so ensure your shoulder harnesses aren't so tight that you can't sit straight up in the seat.

I agree that a helmet can be a real safety item. I also agree that a "negative G strap", or crotch strap is a great addition to any harness system. They are pretty much impractical in most airplanes which have movable seats, however. They will prevent submarining, though one may sing suprano henceforth.

With any accident, the angle of arrival and deceleration is what often determines the outcome. The problem with the three point, or diagonal harnesses, is that they are pretty easy for the body to deform around.

I'm not sure what your discussion of not tightening shoulder harnesses is about....if you tighten most shoulder harnesses, they straighten your back up against the seatback. So, ??

Many general aviation seats are also designed to collapse predictably in an impact, in fact, ALL aircraft designed under FAR 23 are required to meet standards for seat design. That's why it is important NOT to put stuff under those Cessna rear jump seats, or other aircraft seats. The space under those seats is the collapse space, where the seat and your butt is supposed to go if something ugly happens. So, put a camera under that seat, and it may wind up inserted in a very uncomfortable place.

I do believe they have surgical procedures for that, but.......

MTV

Jr.CubBuilder wrote:That's exactly why I bought the BAS harness for my plane, despite my best efforts to train myself I would end up landing with the shoulder strap loose. There's just enough pilot stuff going on during base-final that inevitably I'd forget to tighten it back up after loosening it to grab the flaps.

Granted that BAS is the cadillac on the market, but since my plane came with Hookers, I'm still using them, at least until the next annual. (Have fun with that one, Gump).

Somewhere else on this site, somebody wrote in about hooking the button on their Cessna flaps bar with their toe, to avoid having to loosen shoulder straps. I tried that, and I've been doing it routinely ever since. Works in summer with sneakers or boots, and works well in winter as long as I fly in my Steeger mukluks.

Here's another question- Does anyone have experience with using shoulder belts in the Back seat of a C-170B? If I do get the BAS for the front seats, I was thinking of adapting the Hookers for the rear seat. Not sure if this is feasible, or advisable. I have the stock rear bench seat, BTW.

Thanks,
-DP[/i]

Most shoulder harnesses have one inertia reel and therefore the two straps that come across your chest come together before the reel. Most people will adjust the shoulder harnesses to where the point that they come together lies on the back of their neck. If they try to straighten their back completely straight, they can't, the shoulder straps pull on the back of their neck and will not allow their back to go straight. Don't do that, it can cause problems if your thrown backwards after bouncing off of whatever is in front of you.

Ah, okay thanks. Yet another advantage of the BAS harness: The shoulder straps don't adjust in length, only the lap belts.

I've never seen inertial reel harnesses in the back seats of Cessnas. Don't know what you'd attach them to, actually, since there's really no structure back there, just skins and bulkheads.

The later model Cessnas had three point harnesses in the back seats, attached to the window/door frame structure.

MTV

Why crash to begin with?

1 Go up a canyon you shouldn,t have.

2 Engine failure (most of witch is fuel starvation)

Either way if you cannot resist the urge to pull back on the yoke you stall and either spin or pancake in. You are dead no matter what you have on in a 182B and most other stuff we fly.

If on the other hand you fly the plane at minimum speed to the acident site, you have a chance of survival. We can stand more load on our boddies going strait in than doing a but flop.

Any shoulder harness is better than no harness. Even with the Hooker it seems that if it is a bit loose (not floppy loose) just enough to reach the flap handle, you will stay off the pannel. If you hit so hard that your boddy turns to fluid and you squirt through the harness or under the belt, then who gives a crap.

Tim

I installed a set of BAS belts in my 172 taildragger/floatplane since it only had lap belts. Will be adding them to my 180 as soon as I pay off the new engine. I am wary against flying anything with a V-Brace that doesn't have BAS belts installed. I like to sit as far forward as possible to look ahead of the wings in canyon turns. The 185 I fly has a set installed and I have to buckle each passenger in, even after I have them watch me buckle up. If your co-pilot doesn't fly fighters, race cars or own a go-cart, you will have to strap them in. I only wish BAS would STC for the Beaver, since I reach for the flap selector and the reel locks up on me.

menendez777 wrote:I installed a set of BAS belts in my 172 taildragger/floatplane...Will be adding them to my 180 as soon as I pay off the new engine...I like to sit as far forward as possible to look ahead of the wings in canyon turns...The 185 I fly has a set installed...I only wish BAS would STC for the Beaver...

Menendez777, It sounds like you have waaay too much fun

Tim,

Wear those harnesses a little too loose, and you can snap your neck in the stop--let too much motion start, then stop suddenly, and things break.

Just a thought. You are correct that any PROPERLY WORN harness is better than none.

MTV

Denali,

The 185 and the Beaver are not mine, but I wish they were. My personal ride is a 180K on edo's. Headed back to Maine Monday for my days off. Can't wait for fishing. Will install the BAS harness in the 180 soon, I'm with MTV on these. I've seen the install and have used them daily. Recommended to everyone that involves themselves with backcountry and bush flying.

Check out "schroth" harnesses. Five point belt used by Airbus, and formula 1 racing teams. Has an inertial reel shoulder harness that is easily releasable after takeoff by pressing a simple tab. Installs into pre-tapped overhead wing spar on Cessnas.

dlhanst wrote:Check out "schroth" harnesses. Five point belt used by Airbus, and formula 1 racing teams. Has an inertial reel shoulder harness that is easily releasable after takeoff by pressing a simple tab. Installs into pre-tapped overhead wing spar on Cessnas.

Probably not pre-tapped on a 182B. Are they STC'd?

Tim

What's the reg that states that an owner can install whatever safety belt retention system he wants without requiring field approval or STC?

I imagine this is the case until a hole and rivnut are required to attach to the rear carry-through spar.

Zane,

From the 170 web site:

11. Install shoulder harnesses. (Remember that shoulder harnesses do not have to be PMA'd, STC'd, or TSO'd for installation in a 170B, because you don't have to cut/weld/alter the airframe...the B already has the #10 rivnut installed in it's rear spar....so you can use experimental, automobile, non-certified cheapies if you wish...just install some! The authority for this statement is FAA Policy Statement Number ACE–00–23.561–01)

http://www.faa.gov/aircraft/gen_av/harn ... policy.pdf

There should be two tension straps that run from between the bulkhead behind the baggage compartment and the upper fuselage skin and terminate in a pair of # 10 rivnuts in the inner flange of the next bulkhead forward. There are two # 10 nut-plates and the necessary holes in the aft spar, making it a really simple installation. At least it is that way in my 1954 B-model. The installation provisions do not appear adequate by inspection, but I ran a few rough calculations and it is a reasonably strong arrangement.

Jake

Part of the NTSB report on Berk's accident follows:

"The left front (pilot's) station was equipped with a shoulder harness with an inertia reel mounted to the forward carry through spar and a seat belt mounted to the cabin floor. The attach points for the inertia reel and the seat belt remained intact. The webbing was cut in three places. When the webbing extending from the inertia reel was given a sharp pull by hand, the reel locked. Comparison of the pilot's station shoulder harness installation to installation instructions provided by BAS Incorporated indicated that the installation appeared to conform to the instructions.

The right front station (passenger's station) was equipped with a shoulder harness without an inertia reel and a seat belt mounted to the cabin floor. The attach points for the seat belt remained intact, and the webbing for the seat belt and shoulder harness remained intact. The shoulder harness attach point to the forward carry through spar failed. The shoulder harness was bolted with one AN4 bolt to a nut plate that appeared to have been attached to the carry through spar by two rivets. The nut plate was torn from the carry through spar. The rivets were not recovered. Examination of the carry through spar revealed that four holes had been drilled in the carry through spar where the nut plate was attached; proper attachment of the nut plate would have required only three holes, two for rivets and one for the bolt. Comparison of the passenger's station shoulder harness installation to installation instructions provided by Aero Fabricators and by BAS Incorporated indicated the installation did not conform to either set of instructions."


Maybe Berk told his wife to tighten up her harness prior to impact. Berk's head impacting the door post is what did him in. the Bas harness shoud have kept him away from the door post.

Tim

Tim,

It's hard to evaluate the effectiveness of shoulder harnesses in general in an accident scenario.

Note that in this case, the passenger side shoulder harness failed, but the person in that seat survived. So, that would suggest you don't need harnesses, right?

Not really.

Shoulder harnesses are not designed to control side loads, and there's no way they could. In this case, there was obviously some side loading to have the result it had. The passenger's head probably also moved forward and to the left, but in that case, there wasn't any structure to hit, even though the harness failed.

So, would that scenario have been survivable in any case? Perhaps if he'd been wearing a helmet, as a64 suggested. Otherwise, who knows?

The point is that harnesses are not going to protect you from every conceivable impact scenario. Nothing will short of just not crashing. That's a nice concept, but the execution seems to be a little tougher to pull off.

Again, take a look at the BAS web site. Look at some of the mashed up airplanes where people survived, largely due to good harnesses.

MTV

Some thoughts about Berk's accident report:
1) I find it difficult to believe that the shoulder harnesses attached to the forward spar carry-through, considering that it is pretty much over the pilot's head. I'm betting it was the aft spar carry-through.
2) How was the webbing cut on Berk's harness? Maybe it was cut in an attempt to remove him from the wreckage?
3) On the copilot's side, how was the nutplate torn from the spar carry-through? It is inside/above the spar carry-through. Even if the rivets were to let go, in this case the rivets seem to just serve to anchor the nutplate in place until you can run the bolt into it. Unless of course the entire nutplate was pulled through the spar carry-through. This part of the report does not make sense to me.
I have an inertia-reel harness mounted to the aft spar carry-through on my 150/150. There was a nutplate in it at the appropriate location. I don't know if it was factory or not, but it would be a bear to put that nutplate in unless the cabin top was de-skinned.

Eric

when I installed my 4-points from Wag, the install instructions mentioned factory installed nut plates...my 67 182 had them....#4 on pilot side and #3 on passenger side????guess they installed whatever was on the floor...I opted to use the heavier duty hardware furnished with the kit...had to drill through top skin to install strip washer and nut..better distribution of load on the carry through..couldn't see the logic of trusting the threads of a #3 nut plate to save a life.....