Van's Air Force
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Rear seatbelts
- Thread starter bob888
- Start date
Auburntsts
Well Known Member
Not an engineer, but my only concern would be that the location of any hardpoint in the cabin top would not be aft enough to make the shoulder harness angle acceptable. IIRC ideally you want the harness angle from attach point to shoulder of the pax to be closer to 0 deg (ie horizontal) rather than 90 deg (ie vertical) for strength. This is based upon a vague recollection of something I read in a Tony Bingelis book once upon a time. YMMV....
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NovaBandit
Well Known Member
I agree with Todd. I don't know that there is enough distance between the rear seat backs and the end of the cabin top to get the needed angle.
This link: http://www.formula1-dictionary.net/safety_seat_belts.html
is written for formula one cars, but the same concepts apply here. The one thing that is going to help keep you alive in the event of a crash isn't something that I'd feel comfortable experimenting on, unless I were a mechanical engineer.
This link: http://www.formula1-dictionary.net/safety_seat_belts.html
is written for formula one cars, but the same concepts apply here. The one thing that is going to help keep you alive in the event of a crash isn't something that I'd feel comfortable experimenting on, unless I were a mechanical engineer.
Agree
Seat belts are no place for TLAR engineering...
Seat belts are no place for TLAR engineering...
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Bill Dicus
Well Known Member
Rear belts
From a flight medicine perspective 0 degrees (horizontal) is almost the worst possible choice, due to compressive loads on the spine producing compression fractures in vertebrae with forward torso movement in sharp deceleration. Van likely knows this and worked hard to get the shoulder belts more vertical. Lots written on this.... (Old flight surgeon). Not sure about strength of attachment issues but bet Van considered these. Thanks.
From a flight medicine perspective 0 degrees (horizontal) is almost the worst possible choice, due to compressive loads on the spine producing compression fractures in vertebrae with forward torso movement in sharp deceleration. Van likely knows this and worked hard to get the shoulder belts more vertical. Lots written on this.... (Old flight surgeon). Not sure about strength of attachment issues but bet Van considered these. Thanks.
additional data...
This got my curiosity up, always wondered benefit versus risk on use of shoulder harnesses for back seat occupants (much like an airliner occupant in some ways). Found this somewhat dated, however, I read it as a well thought out and data supported analysis of seat belt use in GA. Lets face it people-, plane-, and crash-dynamics have been the same for quite some time. The author suggests an optimum angle for the shoulder (torso) strap is -5 to 30 deg from the horizontal falling within the Vans installation (and also the 25 deg mentioned).
www.dtic.mil/dtic/tr/fulltext/u2/739943.pdf
This got my curiosity up, always wondered benefit versus risk on use of shoulder harnesses for back seat occupants (much like an airliner occupant in some ways). Found this somewhat dated, however, I read it as a well thought out and data supported analysis of seat belt use in GA. Lets face it people-, plane-, and crash-dynamics have been the same for quite some time. The author suggests an optimum angle for the shoulder (torso) strap is -5 to 30 deg from the horizontal falling within the Vans installation (and also the 25 deg mentioned).
www.dtic.mil/dtic/tr/fulltext/u2/739943.pdf
