Let me emphasize the importance of using a Temperfoam or Comforfoam seat
bottom cushion. Two years ago I flew my Lancair 360 when the engine
quit after only 8 hours from new, because the fuel transfer system
failed. I had to deadstick into a small field. A Lancair glides like a
brick so I had a long flare at the bottom. According to the FAA, I
clipped a tall tree, which caused me to land in a horizontal attitude,
but with a very high descent rate, and little forward speed. =46rom my
experience with ejection seats, I estimate that I pulled between 25 and
30 Gs. It was enough to snap the main spar, break the crankshaft and
break off the rear fuselage. I survived with relatively minor injuries,
broken ribs, two broken teeth and a very badly sprained neck. I believe
that this was due to two things. I had used Temperfoam with all 3
grades of hardness for the seat cushions, and I had repositioned the
upper seatbelt attachment points to the upper fuselage just behind the
canopy. The original seatbelt point is below the pilot's shoulder level
and well back, so that there is always some slack left, and it will
increase the likelihood of spinal injury.
If I had used ordinary upholstery foam, I think that I would have broken
my spine. Ordinary foam would have rebounded and increased the stress on
my back. As it was, I lost one full inch in height as the discs all
compressed. The original seat belt location would also have increased
the spinal loading. As it was the belt held rock solid, and I just had
bad bruising. Now that I am building a Europa, I see the same issues,
especially the upper seat belt mounting position. As you can guess, I
am using Temperfoam and have repositioned the upper belt mountings in a
similar way to that done by Frans Veldmann. I don't care if the seat
feels hard (it didn't), I want the protection.
As a slightly amusing side effect, I used to have a bad back, and
occasionally a slipped disc. Since the crash, my bad back is almost
cured, with no slipped discs; but I don't recommend it as a treatment!
Jerry Fisher
On Sep 14, 2013, at 2:21 PM, GRAHAM SINGLETON wrote:
Fred Klein is right. Soft foam and a hard landing (not damaging the
airplane)
will probably cause serious back injury. Think about it, the foam will
still be compressing
and you are still going down ,when the airplane has started its bounce
so you hit the seat base twice as hard.
Best seat cushion is a styoroam bean bag in this situation.
Graham
From: Fred Klein <fklein@orcasonline.com>
Sent: Saturday, 14 September 2013, 14:56
Subject: Europa-List: europa-List: Re: Factory upholstery kit
On Sep 13, 2013, at 1:09 AM, Kelvin Weston wrote:
> I ordered enough foam for two seats to allow a bit of experimenting
and this only cost 20 uk pounds. Well worth the expense and time
getting it right if I'm going to spend several hundreds on the final
upholstered article.
Kelvin...I would urge that you consider using the very special (and
quite spendy) temperfoam for the seat bottoms rather than upholstery
foam...your tush will be very appreciative. My seat bottoms are 1" of
the green "crash foam" (very dense), 1" of blue (less dense), plus
triangular wedges of upholstery foam...it could save you some trauma
---From a hard landing...sorry but I cannot source this material for you.
Good luck,
Fred
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