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-   -   Retractable front seat belt (https://vansairforce.net/community/showthread.php?t=148023)

Greenley 03-26-2017 10:42 AM

Retractable front seat belt
 
Has anyone used these or have other thoughts for a seatbelt with a retractable shoulder harnesses for the front seats on the RV10? My wife is really pushing for this.

Corbeau 2 Inch Retractable Harness Belts
https://www.quadratec.com/products/24248_300X_PG.htm

Snowflake 03-26-2017 11:02 AM

Tell her it's an airplane, not a Honda Accord. :)

ERushing 03-26-2017 12:58 PM

Take a look at Mark Cooper's build log. I think he ran his mod by Van's as well.

leok 03-26-2017 01:09 PM

With the inertial locking it should work fine. Inertial locking retractors are not sensitive to mounting position.

Having said that, there are some down sides;

(1) They may not be sensitive enough to hold the shoulder straps during turbulence. Inertial locking usually takes a fairly strong pull to lock.

(2) Inertial locking reels also by definition pay out some amount of webbing before locking allowing more excursion of the occupant before providing restraint. Perhaps critical in severe crashes, depending on many factors.

(3) the 2" webbing provides a narrower footprint than 3" due to the narrow width. 3" spreads the loading out more during more severe crashes giving less injury and better restraint. This might be critical for big people, not so much for small folks. (Also belt pads can help here.)

The bottom line is, how much margin vs. convenience/comfort do you want. There are trade offs.

For example, in our cars, as a society, we have traded off the discomfort and the difficult process of buckling race style 5 point seatbelt safety margin for comfort and convenience.
2" belts in cars do pretty well on there own up to around 15-18 mph barrier type impacts. Beyond that airbags typically needed to supplement upper body restraint in a modern car. There is typically about 11% stretch in the belt webbing, spool out while locking the retractor (if applicable) and extension of the upper body/neck/head.
With a double shoulder belt there is some additional margin, but not as much as you would think. Energy increases as the square of velocity making small increases in impact velocity significant.

Greenley 03-26-2017 01:22 PM

Thanks for the info, had not thought about 2" versus 3" straps, excellent point. I noticed these and they were a lot cheaper than Hookers, but as I look at the Hookers, they are mainly 1 3/4" or 2".

RONSIM 03-26-2017 01:39 PM

Did not like them in my Cessna 182
 
We installed them, but, in turbulence, I like to really "snug down" --- cannot do that with an inertia reel.

Ron

vfr800 03-26-2017 02:07 PM

Lap vs should straps for turbulence
 
Seems most turbulence is dealt with by the lap belt. (I'd call a sudden stopping force/impact something more than turbulence. :o)

The prior RV I flew regularly had inertial reel shoulder harnesses, but the lap belts were not on an inertial reel and could be independently tightened. Keeping those snug kept us secured to the seat in any (usually up/down) turbulence. Shoulder harnesses handle the fore/aft load.

Admittedly it might have been a top of the cap button experience with the canopy that taught me this lesson in my first RV...

Isn't it the lap belt tightness/security that matters for bouncy air? That's been my experience at least. Beyond being interconnected, what am I missing that would keep traditional lap belts from holding you secure in turbulence when used in conjunction with inertial shoulder harnesses?

togaflyer 03-26-2017 03:07 PM

I went with the hookers with inertial reals for the front. I also went with cam locks instead of the standard. The inertial real system will drop down about 2 inches. Im tall and tested headroom for passengers getting in the rear seat. Not an issue. I would not have them in an acrobatic plane, but I like them for flying. Hooker offers SnF specials. If you order them, sure you get the nylon tabs for the buckle releases.

Aiki_Aviator 03-26-2017 03:28 PM

Crow
 
Quote:

Originally Posted by Greenley (Post 1160810)
Thanks for the info, had not thought about 2" versus 3" straps, excellent point. I noticed these and they were a lot cheaper than Hookers, but as I look at the Hookers, they are mainly 1 3/4" or 2".

Have a look at Crow harnesses also.

Lan Vinh Do 03-26-2017 04:28 PM

Wish i didn't had it
 
I have a rv-10 with retractabke front seat belt. Would like not to have it. I would like to be able to have a little bit of slack on my shoulder and i can't.

Greenley 03-26-2017 06:25 PM

That was one thing I liked about the Corbeau harness, you could turn the inertial real mechanism on and off. Because sometimes you feel like it and sometimes you don't.

Auburntsts 03-26-2017 06:41 PM

I'm not against inertial reels but I'm not sure I really understand the desire to install them. Is there an issue are you trying to resolve?

ppilotmike 03-27-2017 08:42 AM

Comfort..
 
..is the only reason I can think of for having inertial reels on the shoulder belts. Being able to lean forward and grab something, etc. I'm thinking hard about them too, as comfortable straps is an important feature in a CC cruiser. However, I haven't fully gone through all the considerations regarding safety and may eventually conclude that it's not worth it.

The same goes for the 5th point crotch strap lugs in the rear seats. I'm assuming the rear seat restraint system is designed to INCLUDE the 5th point as part of the restraining system, but a lot of 10 builders are reportedly cutting them off to make all seats have the same 4-point set up. I guess the thinking is that the crotch strap is not so comfortable. However, I can't help thinking about a crash where the rear occupants might impact the forward occupants because the crotch strap isn't present.

Has anyone investigated these options with Vans?

Auburntsts 03-27-2017 08:56 AM

Quote:

Originally Posted by ppilotmike (Post 1161039)
..is the only reason I can think of for having inertial reels on the shoulder belts. Being able to lean forward and grab something, etc. I'm thinking hard about them too, as comfortable straps is an important feature in a CC cruiser. However, I haven't fully gone through all the considerations regarding safety and may eventually conclude that it's not worth it.

The same goes for the 5th point crotch strap lugs in the rear seats. I'm assuming the rear seat restraint system is designed to INCLUDE the 5th point as part of the restraining system, but a lot of 10 builders are reportedly cutting them off to make all seats have the same 4-point set up. I guess the thinking is that the crotch strap is not so comfortable. However, I can't help thinking about a crash where the rear occupants might impact the forward occupants because the crotch strap isn't present.

Has anyone investigated these options with Vans?

Hmmm - OK I guess. If I need to reach something typically I just loosen the shoulder straps all the way -- if that's not enough slack then once they are loose I just slip out of them, lean over and do whatever it is I need to do, then tighten them back up. No big deal whatsoever.

As far as the rear crotch straps, I'm one of those who opted not to install the crotch lug and went with a 4-point harness in the rear and I have zero concerns about that decision. YMMV....


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