Summary
The FAA proposes to revise an earlier proposed airworthiness directive (AD) that applies to all Air Tractor, Inc. (Air Tractor) Model AT-602 airplanes. The earlier NPRM would have required you to repetitively inspect (using the eddy current method) the wing center splice joint two outboard fastener holes on both of the wing main spar lower caps for fatigue cracking; repair or replace any wing main spar lower cap where fatigue cracking is found; and report any fatigue cracking found. The NPRM resulted from fatigue cracking at the wing center splice joint outboard fastener hole in one of the wing main spar lower caps. Since issuing the NPRM, the FAA has received and evaluated new information that decreases the compliance time to initially inspect certain serial numbers. This proposed AD includes the new compliance times in the table located in paragraph (e)(2) of this AD. Since these actions impose an additional burden over that proposed in the earlier NPRM, we are reopening thecomment period to allow the public the chance to comment on these additional actions.