AD NUMBER: 2003-07-04 MANUFACTURER: Air Tractor SUBJECT: Airworthiness Directive 2003-07-04 SUMMARY: This amendment adopts a new
airworthiness directive (AD) that applies to certain Air Tractor,
Inc. (Air Tractor) Models AT-300, AT-400, AT-400A, AT-401, AT-401B,
AT-402, AT-402A, AT-402B, AT-501, AT-502, and AT-502B airplanes.
This AD requires you to repetitively inspect the vertical fin front
spar fitting for cracks and replace any cracked fitting found. This
AD also requires you to install a steel doubler as a terminating
action for the repetitive inspections. This AD is the result of a
report of failure of a 1/4--inch thick vertical fin front spar
fitting. The actions specified by this ADare intended to prevent
failure of the vertical fin front spar fitting, which could result
in failure of the rear spar fitting. Such failures could lead to
loss of directional control of the airplane.