Summary
This document proposes to revise an earlier proposed airworthiness directive (AD) that would apply to certain Air Tractor, Inc. (Air Tractor) Model AT-602 airplanes. The earlier NPRM would have required you to repetitively inspect the left hand upper longeron and upper diagonal tube of the fuselage frame for cracks and repair any cracks found. The earlier NPRM would have also required eventual modification of this area to terminate the repetitive inspection. The manufacturer has identified additional airplane models on which the unsafe condition exists or could develop and has determined that the required modification is not eliminating the cracks from occurring. This proposed AD adds additional airplanes to the applicability and makes the inspection repetitive for all airplanes even if the modification is incorporated. Since these actions impose an additional burden over that proposed in the NPRM, we are reopening the comment period to allow the public the chance to comment on these additional actions.