Textron Bell 412, Maintenance Manual

Page: 107 / 288

BHT-412-MM-2
5-00-00
01 JUN 2018 Rev. 26 Page 71 Export Classification C, ECCN EAR99
NOTE
Step 10 pertains to helicopters S/N 36020 through
36999, S/N 37002 through 37999, S/N 38001
through 38999, S/N 39101 through 39999, and
helicopters modified by 412-570-001-103 or Post
BHT-412-SI-74 (412SP to 412HP Upgrade).
Chapter 65 10. Intermediate gearbox:
a. Gearbox assembly for security, condition, corrosion,
damage, and oil leaking.
WARNING
CAUSE OF ANY DISCOLORATION SHALL BE
DETERMINED AND CORRECTED PRIOR TO
NEXT FLIGHT.
b. Output quill outer couplings (and surrounding area) for
grease leakage, damage, corrosion, and evidence of overheat
as indicated by TEMP-PLATES or coupling discoloration. A
change in color of one or more of the red bordered
TEMP-PLATE dots from white/off-white to black indicates an
overheat condition and may require replacement of both outer
and inner couplings (step c).
c. Overheat TEMP-PLATES for condition and security.
TEMP-PLATES must not show evidence of over temperature
indication, deterioration, debonding, or excessive discoloration
of the epoxy overcoating.
d. Gearbox for proper oil level and oil for evidence of
contamination.
NOTE
Step 11 pertains to helicopters S/N 33001 through
33213 and 36001 through 36019 not modified by
412-570-001-103 or Pre BHT-412-SI-74 (412SP to
412HP Upgrade).
SCHEDULED INSPECTIONS
5-9. 25 HOUR/30 DAY INSPECTION — PART B (CONT)
DATA REFERENCE INSPECTION TASK DESCRIPTION
INITIAL
MECH OTHER