Mark Langford has a nifty little program that gives you all the = pertinent data regarding spar depth/construction and strength figures. A simple multiplication of this info against the moment arm SHOULD get you in the ballpark. Again I'm no engineer either.
Doug =20 As far as changing the spar goes, check the archives for information on = the effects of longer wings; there have been LOTS of discussions on this. = Then you will need to consult some good engineering/aviation design software. Lengthening the spar without making it larger in the middle sounds to me like asking for trouble, BUT I am not an engineer, so consult the = software and those who know for answers BEFORE cutting any wood. The Dan Diehl = wings skins is the longest I have heard of the wings being without = modification, and it does not effect the original spar. The new wing requires the = spar to be taller, but not longer... =20 =20 Colin Rainey =20 --=20 No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.371 / Virus Database: 267.14.21/236 - Release Date: = 1/20/2006 =20