Maintenance Manual STEMME S10-VT
Date of Issue: Jan. 01, 1998
Page 7-20
Amendment Nr. 8
Date: Nov. 11, 1999
A4011121_B23.doc
Doc. No. A40-11-121
7.4.10.3 Visual Inspection of the Propeller Unit
Check load bearing elements (hub and forks, blade suspension) for cracks, corrosion and other damage.
Check complete propeller assembly for loose components, loose bolt connections or other apparent damage.
Check condition of rubber stops within the blades and on hub for cracks. Check propeller blades for cracks or
other damage, specially at blade tips, at bonding seam and in the area of stop buffers. Repair leading edge
protection tape if necessary (use material supplied by the manufacturer only!). Check propeller folding
mechanism for ease of operation and restoring force. Check propeller blade ventilation and drain holes at the
blade tips, clean if necessary.
If the engine retarder module failed during engine start, the propeller must be checked for damage. Special
attention is then to be paid to the condition of the following items: blade sided rubber stops and surrounding
blade structure, stop bolt in the blade suspension forks and the blade retraction coupling levers.
7.4.10.4 Removal of the Propeller Unit
Remove the propeller dome: remove left and right foot-well covers. Loosen clamp bolt at the guide block
of the propeller dome, pull out locking screw with dom spring, pull off pressure lines, pull nose-cone off to
the front.
Unscrew the front cover of the variable pitch mechanism.
Unscrew both sides of the electric covers (three M3 bolts).
Disconnect the power supply to the electric element on both sides.
Disconnect the drive pin (10) from the fork (4), (one M5 bolt, one M8 nut, one of the two adjustment
screws (25), the second adjustment screw remains secured to facilitate finding the original position).
NOTE:
A counter-balancing weight washer may be attached to the inside of the fork by means of an M5 bolt.
This washer must be re-installed at the same place on re-assembly.
Loosen both bolts (M6 with secure washers) to separate the variable pitch mechanism from the hub
centrepiece (18). Remove the variable pitch mechanism to the front.
Loosen the six M8 bolts (three bolts in each group secured with safety wire) connecting propeller hub and
front gear. Remove the hub (with the propeller) to the front.
7.4.10.5 Installation of the Propeller Unit
Clean and degrease the propeller and the front gear flange with an appropriate solvent. The torque is
transmitted by friction fit, therefore, the surfaces must be even, clean and free from grease.
Inspect threaded bushes in the front gear flange for visible damage.
Insert carbon brushes fully into their supports and temporarily fix with adhesive tape (or similar) to avoid
damage on the brushes and their supports when the hub is fitted to the gear flange.
Tighten the M8 bolts securing the hub to the gear flange, using crosswise a torque wrench in two steps:
Step 1: torque 10 Nm / 7.4 lbf ft
Step 2: torque 30 Nm / 22.1 lbf ft
and then secure groups of three bolts together using safety wire (diameter 0.8 mm / 0.03 in.).
Mount variable pitch mechanism on the hub centrepiece (18) and fasten with bolts (two M6 bolts with
locking washers). Pay attention to red marks.
Release carbon brushes and check contact and appropriate pressure on the respective slip rings.
Bolt the drive pin (10) onto both sides of the fork (4). Attach M5 bolts first and then screw on the M8 bolts
loosely, then tighten the loose adjustment screw (25) and secure by countering. Then tighten the M5 bolt
and the M8 nut (using a torque wrench, torque 20 Nm / 14.7 lbf ft). Secure the adjustment screws with
safety wire.
NOTE:
If necessary, bolt the counter- balancing weight washer back at the inside of the fork.
