cyclic pitch stick in neutral. Visually examine the
control lock cylinder to make sure that the pin is
aligned with its hole.
When the controls are
positioned, trip the FOLD manual override on the
blade fold control valve and hold it in this position.
No action should result. Release the override.
Position the SAFETY VALVE switch to OPEN.
Check that the SAFETY VALVE OPEN light comes
on. Trip the manual override again. The dampers
will position, the control lockpin will engage, and the
blade lockpin will disengage. The blade will fold, and
the PRI SERVO PRESS light will go off.
Ensure that the path of the blade is clear
before tripping the manual override.
Failure to do so could result in personal
injury or damaged to the aircraft. The
cyclic control stick may have to be moved
slightly around neutral to engage the
Check the lights on the blade fold panel. CONT
LOCKPIN ADV, BLADE FOLDED, CHECK
BLADE FOLD, SAFETY VALVE OPEN, AND
ACCESS DR ON lights should be lighted. The
BLADE SPREAD light should be off. Trip the
manual override button to SPREAD. The blade will
spread and the lockpin will engage. The control
lockpin will disengage. The BLADE SPREAD and
CHECK BLADE FOLD lights will come on. Position
the SAFETY VALVE switch to CLOSED. Check to
see that the SAFETY VALVE OPEN and CHECK
BLADE FOLD lights go off within 1 1/2 seconds and
that the FLIGHT POS light comes on. Release the
rotor brake to make sure that the ROTOR BRAKE
ON light goes off. Manually reposition the No. 1
blade to the right of the helicopter centerline.
Position the safety valve switch to OPEN and the
master switch to ON. Make sure that SAFETY
VALVE OPEN and FOLD PWR ON lights come on.
Check to see that the ACCESSORY DR ON light is
on. The rotor brake should disengage automatically.
Hydraulic pressure should disengage the blade
positioner drive unit from the rotor brake disc.
The final movements of blade positioning may
result in a position hunting motion or chatter. If this
chatter is sustained for more than 3 seconds, investi-
gate the cause.
Position the blade fold switch to
FOLD. The No. 1 BLADE POSITION light will
come on. Apply the rotor brake manually. Damper-
positioners will position, the control lockpin will
engage, and the CONT LOCKPIN ADV light will
The blade lockpin will retract, and the
BLADE SPREAD light will go off. The BLADE
FOLDED and CHECK BLADE FOLD lights will
NOTE: Automatic fold cycle time is
approximatey 30 seconds for the rotary-wing
positioning. The normal time for damper
positioning is 5 seconds, and normal time for
blade folding is 27 to 41 seconds.
Make sure that the accumulator gauge on the No.
1 blade sleeve spindle maintains 3,000 psi. The
damper-positioners should remain in full extended or
autorotative position. The blades should remain
folded. Position the blade fold switch to SPREAD,
and check the reversing of operation.
BLADE SPREAD light comes on, position the safety
valve switch to CLOSED (SAFETY VALVE OPEN
and FOLD PWR ON lights should then go out).
Position MASTER and BLADE FOLD switches to
OFF. CHECK BLADE FOLD light will go off, and
FLIGHT POS light will come on. Visually check
control lockpin for disengagement. Move the No. 1
blade to the left of the helicopter centerline. Repeat
the automatic folding sequence. Following the
hydraulic testing, inspect all components for external