"I believe it would be wise to put the seats on the spars, if at all possible."
I think that Mark is being kind to use the word "wise". Seems to me that a 1/2 g drop as in a hard landing would place a sudden 100 pound load (assuming a 200 pound pilot) on the floor/side wall structure. The pilot might find his bottom sliding along the runway. During construction I dropped a 2 foot 2X4 from 8 foot. When it hit the bottom of the boat, it took out the floor and a cross member. Orma Southfield, MI N110LR Tweety, old enough to drink this year Flying and more flying, to the gathering or bust http://www.kr-2.aviation-mechanics.com/
