light comes on. Place the collective pitch stick in the
BLADE SPREAD light will go off. The BLADE
full low position and the cyclic pitch stick in neutral.
FOLDED and CHECK BLADE FOLD lights will
Visually examine the control lock cylinder to make
come on.
sure that the pin is aligned with its hole. When the
N OT E : A u t o m a t i c f o l d c y c l e t i m e i s
controls are positioned, trip the FOLD manual override
approximately 30 seconds for the rotary-wing
on the blade fold control valve and hold it in this
positioning. The normal time for damper positioning
position. No action should result. Release the
is 5 seconds, and normal time for blade folding is 27 to
override. Position the SAFETY VALVE switch to
41 seconds.
OPEN. Check that the SAFETY VALVE OPEN light
comes on. Trip the manual override again. The
Make sure that the accumulator gauge on the No. 1
dampers will position, the control lockpin will engage,
blade sleeve spindle maintains 3,000 psi. The
and the blade lockpin will disengage. The blade will
damper-positioners should remain in full extended or
fold, and the PRI SERVO PRESS light will go off.
autorotative position. The blades should remain
folded. Position the blade fold switch to SPREAD, and
Check the lights on the blade fold panel. CONT
check the reversing of operation. When the BLADE
L O C K P I N A DV, B L A D E F O L D E D , C H E C K
SPREAD light comes on, position the safety valve
BLADE FOLD, SAFETY VALVE OPEN, AND
switch to CLOSED (SAFETY VALVE OPEN and
ACCESS DR ON lights should be lighted. The
FOLD PWR ON lights should then go out). Position
BLADE SPREAD light should be off. Trip the manual
override button to SPREAD. The blade will spread and
MASTER and BLADE FOLD switches to OFF.
the lockpin will engage. The control lockpin will
CHECK BLADE FOLD light will go off, and FLIGHT
disengage. The BLADE SPREAD and CHECK
POS light will come on. Visually check control
BLADE FOLD lights will come on. Position the
lockpin for disengagement. Move the No. 1 blade to
SAFETY VALVE switch to CLOSED. Check to see
the left of the helicopter centerline. Repeat the
that the SAFETY VALVE OPEN and CHECK BLADE
automatic folding sequence. Following the hydraulic
FOLD lights go off within 1 1/2 seconds and that the
testing, inspect all components for external leakage.
FLIGHT POS light comes on. Release the rotor brake
Q17-25. What test is required after a helicopter has
to make sure that the ROTOR BRAKE ON light goes
been rigged?
off. Manually reposition the No. 1 blade to the right of
the helicopter centerline. Position the safety valve
Q17-26. P ro p e r b l a d e t r a ck i n g p re v e n t s w h a t
switch to OPEN and the master switch to ON. Make
condition?
sure that SAFETY VALVE OPEN and FOLD PWR
Q17-27. What blade-tracking device can be used in
ON lights come on. Check to see that the
flight or on the ground?
ACCESSORY DR ON light is on. The rotor brake
should disengage automatically. Hydraulic pressure
Q17-28. What assembly is comparable to a single disc
should disengage the blade positioner drive unit from
wheel brake in its design and operation?
the rotor brake disc.
Q17-29. What component prevents hydraulic pressure
The final movements of blade positioning may
from entering the blade fold system during
result in a position hunting motion or chatter. If this
flight?
chatter is sustained for more than 3 seconds,
Q17-30. What is the blade fold accumulator nitrogen
investigate the cause. Position the blade fold switch to
preload pressure that maintains hydraulic
FOLD. The No. 1 BLADE POSITION light will
pressure in the rotary-wing head?
c o m e o n . A p p l y t h e r o t o r b r a k e m a n u a l l y.
Q17-31. Before you charge the blade fold accumulator
Damper-positioners will position, the control lockpin
with nitrogen, the blades should be in what
will engage, and the CONT LOCKPIN ADV light will
position?
illuminate. The blade lockpin will retract, and the
17-20
