Seat Modifications

100% complete

Fiberglass seat reinforcement
The seat in the Kitfox Series 6 is lightweight fiberglass and it is shown here in position.  Underneath the seat run the control push/pull tubes which control the aircraft.  It has been reported that on very rough landings, the seat has flexed and moved enough that it has contacted push/pull tubes and made aircraft control difficult.  I am a lot heavier than the average pilot and I noticed some strain in the fiberglass even in normal sitting, the whole seating system needs to be reinforced.
First I sand the whole assembly and add additional layers of fiberglass, two on the pilots side and one on the passengers side.  I also added two additional three inch strips on the bottom and top edges to help reinforce where the seat attaches to the airframe.  The sides and area between the seats got one layer of additional fiberglass.
Here the additional fiberglass has been installed.

Seat Attachment
The attachment method specified in the manual is to use cable ties to attach the seat to the airframe.  While this is light and quick, there have been problems reported of the cable ties breaking on very rough landings and causing controllability problems as the seat binds against the control tubes. 
For a much more secure method of attaching the seat, I chose cushioned clamps and captive nuts.  A large washer is used under the machine screw head to distribute the load and provide more gripping strength.  Safety wire is used to hold the clamps perfectly in position for easy seat installation.  The hole is drilled in the fiberglass much further from the edge with this method of attachment which reduces the chances of tear-out.
The edges of the seat have been reinforced with two layers of cloth to insure that the holes do not pull out.
Here you can see the cushion clamps holding the seat in place.  Very secure and reliable.
Complete seat installation.

 

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