(h) Initial Inspection for All Affected
Airplanes With Less Than 24,975 Hours TIS
on the Carry Through Spars
Using the compliance times listed in
paragraphs (h)(1) through (3) of this AD, do
a detailed visual inspection of the left and
right forward lower carry through spar cap
for cracks. Using a 10X magnifier visually
inspect the bottom surface of the carry
through spar cap in the areas around the
fasteners located just inboard of the left-hand
and right-hand forward lower wing fittings.
If a crack is not positively identified during
the detailed visual inspection but is
suspected or the area is questionable, before
further flight, do a surface eddy current
inspection of the suspected area. Do these
inspections using the Accomplishment
Instructions in Textron Aviation Multiengine
Mandatory Service Letter MEL–57–01
and Textron Aviation Conquest Mandatory
Service Letter CQL–57–01, both dated
December 18, 2017, as applicable.
(1) For Models 401, 401A, 401B, 402, 402A,
402B, 402C, 411, 411A, 414, 414A, 421, and
421A airplanes: Before the accumulation of
15,000 TIS on the carry through spars or
within the next 50 hours TIS after February
28, 2018 (the effective date of this AD),
whichever occurs later.
(2) For Models 421B and 421C airplanes:
Before the accumulation of 12,000 hours TIS
on the carry through spars or within the next
50 hours TIS after February 28, 2018 (the
effective date of this AD), whichever occurs
later.
(3) For Model 425 airplanes: Before the
accumulation of 11,000 TIS on the carry
through spars or within the next 50 hours TIS
after February 28, 2018 (the effective date of
this AD), whichever occurs later.
