alpinelakespilot2000
Well Known Member
The castle nut on one of my rear spar bolts is not lining up with the hole in the bolt when the nut is tightened anywhere within the 100-140 in-lb range for AN5 bolts. In fact, the difference b/w 100-140 in-lb is insufficient to move the castle nut even 1/2 of a slot! The plans call for regular washers, but I tried replacing one of the washers with the thin (-L) version, still no luck.
The Standard Aircraft Handbook indicates "Except in highly stressed engine parts, the nut may be overtightened to permit lining up the next slot with the cotter pin hole." (p. 151) However, AC43.13-1b says, "If the hole and nut castellation do not align, change washer or nut and try again. Exceeding the maximum recommended torque is not recommended." (p. 7-7)
Given that this is a kind-of-important rear spar bolt, I'm inclined to heed the more conservative AC43.13. So, what's the best way to address this dilemma?
Thanks.
The Standard Aircraft Handbook indicates "Except in highly stressed engine parts, the nut may be overtightened to permit lining up the next slot with the cotter pin hole." (p. 151) However, AC43.13-1b says, "If the hole and nut castellation do not align, change washer or nut and try again. Exceeding the maximum recommended torque is not recommended." (p. 7-7)
Given that this is a kind-of-important rear spar bolt, I'm inclined to heed the more conservative AC43.13. So, what's the best way to address this dilemma?
Thanks.