MAULE AEROSPACE TECHNOLOGY, INC.
MAINTENANCE MANUAL
FOR
MT-7-420
9/02
8
7. Remove wing strut fairings, top and bottom, and inspect attaching fittings and bolts
for security, corrosion and cracks. Carefully inspect both sides of lift struts for abra-
sion, corrosion, pin holes and punctures. Any paint loss or minor corrosion should
be sanded down to bare metal with fine sandpaper and metal primer should be ap-
plied. After the primer is dried, a finish coat of the desired color may be added.
Powder coating is recommended if complete strut is being refinished.
WARNING: Any unrepairable dents or punctures in strut are cause for replacement of
the strut.
CAUTION: This aircraft was equipped with sealed struts when manufactured, however,
if these struts were replaced in field with unsealed struts, comply with Maule Service
Bulletin No. 11 as required. (New sealed struts are identified by two weld spots located
at upper end. Removal of the upper cuff is needed to locate the weld spots).
CAUTION: Item (a)(4) of AD# 98-15-18 is very misleading as Maule never drills holes
in struts to attach cuffs, door clips or any hardware and it is illegal to do so since there
are no approved holes in the wing struts under the TC data. If aircraft has a modifica-
tion added requiring a drilled hole in strut under a #337, refer to AD for inspection re-
quirements at the 24-month intervals. Also, inspect the area around the holes(s) fre-
quently for corrosion or cracking (ref. SL#58).
8. Remove wheels and inspect wheels, tires, brake disc, bearings, brake lines and
brake pad for wear, cuts, chafing, leaks and general condition. Repack wheel bear-
ings.
9. Remove landing gear top fairings and inspect attaching fittings and bolts for secu-
rity, corrosion and cracks and inspect brake hose for security, chafing and leaks.
10. Remove inspection hole cover in fuselage bottom inboard main landing gear (spring
gear) attach points. Visually check bolt/nut attachment for security, both from below
and above. Check fuselage square tube truss for cracks or bending. Carefully in-
spect both sides of the spring gear itself at the inboard attachment and along its en-
tire length for abrasion, cracking, corrosion, exfoliation, mechanical damage, or any
other adverse conditions. Remove any corrosion and prime and paint the affected
area. Spray entire inboard area of spring gear, attachment points, and truss with
LPS-3 Rust Inhibitor (LPS Laboratories, Inc.) or equivalent. The torque on the AN
inboard attach bolts must be 240-300 inch pounds and on outboard clamp bolts
160-190 inch pounds.
NOTE: Service Letter 74 that supersedes Service Letter 66, adds high strength
NAS bolts and tension nuts as the preferred option for outboard and inboard attach
bolts for aluminum spring gears. These bolts require 450-500 inch lbs. torque on
the inboard attach bolts and 160-190 on the outer attach bolts. These bolts listed on
Service Letter 74 affect S/N’s 51001C and 51002C.
CAUTION: Use Steps 9 and 10 above as a guide for inspection after an unusually hard
landing or any time there is concern about the condition of the main landing gears or
their attachments.
