Original Posted By: Ben Charvet
I too have always questioned the strength of the wing to resist forward movement in the event of a crash. The original "X" bracing added one cable to help keep the center section from displacing forward, while the Diagonal struts add two tubes in compression, which may or may not be as strong depending upon the tubing used, it is very posssibly stronger in many installations. The forward facing "drag?" wire in the struts would resist some forward movement, but I"m not sure how much given the narrow/low angle relative to the wing. How many G's are we talking about anyways? what does the entire wing weigh, how much force is involved in a sudden stop?My plane has wooden cabanes and wood diagonal braces with a steel strap inside of them. This design of diagonal would clearly have no compressive strength. I am therefore thinking of using the "X" bracing as well. I was then hoping to feel confident enough to attach the front shoulder harnesses to the center of the "X" formed by the cables (rods in my plane) behind the front pit. Being lower, I felt that if the wing displaced diagonally it wouldn't tighten up on the passenger as much.FYI, like many others, I attached my front lap belt by drilling through the ash crosspiece, and through the steel strap connecting the fittings under the fuselage. However, I went just INSIDE the seat uprights and through two slits in the back of the seat bottom. This is pretty narrow, but really not much moreso than coming up outside the seat sides and it really helps to keep the belt away from the pilot's feet.Douwe________________________________________________________________________________Date: Sat, 12 Apr 2008 13:10:05 -0400
Pietenpol-List: seat belt and shoulder harness
Re: Pietenpol-List: seat belt and shoulder harness
Original Posted By: santiago morete
As many of you know, I don't post to the list much any more, but I thought I'd throw this thought into the mix. The Brits have a PFA- approved design for front passenger shoulder strap & lap belt attachment. It involves a welded assembly behind the front headrest that carries down & attaches at several other points on the fuse (don't recall all the details right now). Someone sent me a scan of the drawing several years ago, unfortunately the quality is not good enough to rescan & send out. Although it will add some weight, it is a very sensible design. Attaching a harness to the cabanes or x- wires gives me the heebie-jeebies just on principle.Kip GardnerOn Apr 12, 2008, at 9:59 AM, Douwe Blumberg wrote:> I too have always questioned the strength of the wing to resist > forward movement in the event of a crash. The original "X" bracing > added one cable to help keep the center section from displacing > forward, while the Diagonal struts add two tubes in compression, > which may or may not be as strong depending upon the tubing used, > it is very posssibly stronger in many installations. The forward > facing "drag?" wire in the struts would resist some forward > movement, but I"m not sure how much given the narrow/low angle > relative to the wing. How many G's are we talking about anyways? > what does the entire wing weigh, how much force is involved in a > sudden stop?>> My plane has wooden cabanes and wood diagonal braces with a steel > strap inside of them. This design of diagonal would clearly have > no compressive strength. I am therefore thinking of using the "X" > bracing as well. I was then hoping to feel confident enough to > attach the front shoulder harnesses to the center of the "X" formed > by the cables (rods in my plane) behind the front pit. Being > lower, I felt that if the wing displaced diagonally it wouldn't > tighten up on the passenger as much.>> FYI, like many others, I attached my front lap belt by drilling > through the ash crosspiece, and through the steel strap connecting > the fittings under the fuselage. However, I went just INSIDE the > seat uprights and through two slits in the back of the seat > bottom. This is pretty narrow, but really not much moreso than > coming up outside the seat sides and it really helps to keep the > belt away from the pilot's feet.>> Douwe>>________________________________________________________________________________Date: Sat, 12 Apr 2008 17:09:48 -0300 (ART)
As many of you know, I don't post to the list much any more, but I thought I'd throw this thought into the mix. The Brits have a PFA- approved design for front passenger shoulder strap & lap belt attachment. It involves a welded assembly behind the front headrest that carries down & attaches at several other points on the fuse (don't recall all the details right now). Someone sent me a scan of the drawing several years ago, unfortunately the quality is not good enough to rescan & send out. Although it will add some weight, it is a very sensible design. Attaching a harness to the cabanes or x- wires gives me the heebie-jeebies just on principle.Kip GardnerOn Apr 12, 2008, at 9:59 AM, Douwe Blumberg wrote:> I too have always questioned the strength of the wing to resist > forward movement in the event of a crash. The original "X" bracing > added one cable to help keep the center section from displacing > forward, while the Diagonal struts add two tubes in compression, > which may or may not be as strong depending upon the tubing used, > it is very posssibly stronger in many installations. The forward > facing "drag?" wire in the struts would resist some forward > movement, but I"m not sure how much given the narrow/low angle > relative to the wing. How many G's are we talking about anyways? > what does the entire wing weigh, how much force is involved in a > sudden stop?>> My plane has wooden cabanes and wood diagonal braces with a steel > strap inside of them. This design of diagonal would clearly have > no compressive strength. I am therefore thinking of using the "X" > bracing as well. I was then hoping to feel confident enough to > attach the front shoulder harnesses to the center of the "X" formed > by the cables (rods in my plane) behind the front pit. Being > lower, I felt that if the wing displaced diagonally it wouldn't > tighten up on the passenger as much.>> FYI, like many others, I attached my front lap belt by drilling > through the ash crosspiece, and through the steel strap connecting > the fittings under the fuselage. However, I went just INSIDE the > seat uprights and through two slits in the back of the seat > bottom. This is pretty narrow, but really not much moreso than > coming up outside the seat sides and it really helps to keep the > belt away from the pilot's feet.>> Douwe>>________________________________________________________________________________Date: Sat, 12 Apr 2008 17:09:48 -0300 (ART)
Re: Pietenpol-List: seat belt and shoulder harness
Original Posted By: Kip and Beth Gardner
Scans of the PFA-approved design. http://westcoastpiet.com/seatbelts.htmChris TracySacramento, CaWebsite at http://www.WestCoastPiet.com ----- Original Message -----
Scans of the PFA-approved design. http://westcoastpiet.com/seatbelts.htmChris TracySacramento, CaWebsite at http://www.WestCoastPiet.com ----- Original Message -----