Electric Clock; Wing Leveler; Rigging - Cessna 150 STANDARD Service Manual

15-58. ELECTRIC CLOCK.
15-59. DESCRIPTION. The electric clock is
connected to the battery through a one-ampere fuse
mounted adjacent to the battery box. The clock
electrical circuit is separate from the aircraft
electrical system and will operate when master
switch is OFF.
15-60. WING LEVELER. (Refer to figure 15-8.)
• THRU AIRCRAFT SERIAL 15075525 AND A1500480.
15-61. DESCRIPTION. The wing leveler control
system, consisting of a turn coordinator (15),
pneumatic servos (2), connecting cables (3 and 7) and
hose (1, 4 and 5) may be installed. The turn coor-
dinator gyro senses changes in roll attitude, then
electrically meters vacuum power from the engine-
driven vacuum pump to the cylinder-piston servos,
operating ailerons for longitudinal stability. In
addition to aileron servos, two servos are connected
to the rudder cables and provide lateral (yaw) sta-
bility that prevents excessive changes in heading in
turbulent air. Manual control of system is afford-
ed by the roll trim knob (16). Roll trim should not
be used to correct faulty rigging or "wing heaviness. "
Manual override of sytem may be accomplished
without damage to aircraft or system. The ON-OFF
SHOP NOTES:
15-22 Change 2
valve (14) controls vacuum supply to distributor valve,
but does not affect electrically operated turn coordin-
ator gyro. Installation of wing leveler does not change
vacuum relief valve (18) settings. Refer to appropriate
publication issued by the manufacturer for trouble shoot-
ing procedures.
15-62. RIGGING.
a. Loosen connector (8) and clamp (10).
b. Move aileron to full up position.
c. Move clamp (10) outboard until spring (9) is
extended to 6.50 inches from hole in servo eable end
to hole in clamp and tighten screw and nut.
NOTE
After completion of step" c", servo seal
should be taut but not stretched.
d. Move connector (8) outboard until sleeve contacts
servo cable end, then back off approximately. 06 inch
and torque connector to 70-90 pound-inches.
e. The rudder servos are rigged in same manner
as aileron servos except hold full rudder and pull
servo cable to extend the inactive servo until taut
but not stretched, then secure cable. Hold opposite
full rudder and rig remaining servo in similar man-
ner.