MD Helicopters CSP-900RMM-2, Servicing And Maintenance

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CSP − 900RMM − 2 MD Helicopters, Inc.
Rotorcraft Maintenance Manual
Page 18
Original
53-30-00
C. Anti − Torque Fan Diffuser − Stator and
Diverter Plate Installation
(Ref. Figure 8)
The diffuser-stator and diverter plate
installation includes the installation of the
stator vanes, the upper and lower components
of the center diffuser , the upper and lower
components of the aft diffuser, the diverter
plate assembly, and an electrical access cover.
Stator Vane Assemblies - The stator vane
assemblies function to straighten the air flow
exiting the anti-torque fan. Nineteen vane
assemblies that are supported by the upper
duct and lower access panel.
The stator vane assemblies consist of a vane
with threaded inserts. The vanes are fabri­
cated using glass fiber reinforced polypropy­
lene material that is injection molded.
Upper and Lower Center Diffuser - The
center diffuser consists of an upper and lower
diffuser component that supports the inner
ends of the stator vane assemblies. The upper
center diffuser is attached to the forward end
of the aft diffuser. Attachment of the upper
center diffuser is by the (upper) stator vane
assemblies, screws, and the upper duct of the
aft duct assembly. Attachment of the lower
center diffuser is by the (lower) stator vane
assemblies, screws, and the lower fan access
panel. The upper and lower components of the
center diffuser are aligned by pins that are
retained in the lower.
Both the upper and lower components of the
center diffuser are are fabricated as monolithic
laminates. Each composite laminate utilizes
multiple plies of graphite/epoxy.
Upper and Lower Aft Diffuser - The
combined components of the aft diffuser
function to diffuse the air flow exiting the
anti-torque fan. The process of diffusion,
involves the gradual increase in flow area and
the conversion of air velocity pressure (dynam­
ic pressure) to static pressure.
The upper component of the aft diffuser, is
attached at the forward end to the center
diffuser. At the aft end, the upper component
is attached to the diverter plate assembly. The
lower component of the aft diffuser is sup­
ported by the upper component and is retained
by bolts and turn lock type fasteners.
Both the upper and lower components of the
aft diffuser are fabricated as monolithic
laminates. Each laminate utilizes multiple
plies of graphite/epoxy.
Diverter Plate Assembly
- The diverter plate
assembly is a non-structural component. The
diverter plate assembly turns the air exiting
the fan for alignment with the tailboom. The
diverter plate also supports and fairs the fan
control components that are in the fan airflow
path.
Electrical Access Cover - This access cover
assembly covers the installed electrical
harness, that extends through the tailboom to
the empennage. The electrical access cover is
fabricated from polycarbonate sheet.