CSP−HMI−2
MD Helicopters, Inc
.
MAINTENANCE MANUAL
64−25−30
Page 601
Revision 34
ANTI
−
TORQUE FAN
INSPECTION/CHECK
1. Anti
−
Torque Fan Inspection
Inspect the anti−torque fan for the following
conditions:
(1). All components for cracks, nicks,
corrosion or excessive wear.
(2). Tension−torsion straps for nicks or cuts
in polyurethane coating. No exposed
kevlar fibers allowed. Spools for cracks.
(3). Hub−to−blade bushings for cracks.
(4). Pitch horn for excessive wear (out−of−
round condition).
(5). Counterweights on pitch horn for
security. If loose, perform Pitch Horn
Counterweight Set Screw Replacement.
NOTE:
Access the forward counterweights
through the fan inlet. Fan hub fairing must
be removed for access (Ref. Sec. 53−30−30).
(6). Pitch plate bushing for excessive wear,
grooves or cracking.
(7). Blades for cracks, nicks or impact
damage.
(8). Inspect gap between fan blade and tip
seal. Inspect gap between fan blade and
hub (inboard end of the blade). If any of
these gaps for any blade exceeds the
average gap of the other blades by more
than 0.10 inch (2.54 mm), removed and
inspected the tension−torsion strap for
that blade.
2. Support Shaft Inspection
Inspect the support shaft and its associated
components as follows:
NOTE:
Ensure proper pitch plate and/or sup-
port shaft bearings are installed. 900R bear-
ings are not to be used in the 500/600N heli-
copters.
(1). Support shaft for:
(a). Cracks; none allowed.
(b). Wear.
(c). Scoring; axial marks from bearing
installation or removal.
(d). Damaged spines; none allowed.
(e). Corrosion and pitting.
(2). Fan support bearing for free movement
of set.
(3). Fan support bearing retainer and
housing for:
(a). Cracks; none allowed.
(b). Wear.
(c). Scoring; axial marks from bearing
installation or removal.
(4). Bearing seals for condition.
(5). Hub spacer for cracks and wear.
3. Anti
−
Torque Fan Liner (Felt Metal Seal)
Inspection
(1). Inspect for cracks and debonding of
liner material.
(2). Inspect for cracks around the radius
cutouts of fan support.
(3). If cracks are found, stop drill and
inspect every 50 hours (Ref. Sec.
05−20−20).
NOTE:
Cracks protruding into the Felt Metal
Seal are unacceptable, replace seal (Ref.
Anti−Torque Fan Liner (Felt Metal Seal)
Replacement).
(4). Inspect aft P−seal for tears, deteriora-
tion and debonding.
4. Fan Blade Inspection (100
−
Hour)
Consumable Materials
(Ref. Section 91
−
00
−
00)
Item
Nomenclature
Sealing compound
(1). Inspect polypropylene portion of fan
blade for nicks, scratches, abrasions
and bulges; pay particular attention to
