Because the lockpins pull out only a short
the stabilator AUTO CONTROL PUSH TO
RESET pushbutton is depressed. DAMAGE
distance, they still safely lock the blades in flight
MAY OCCUR TO THE FUSELAGE IF THE
position. Logic circuits in the distributor sense the
STABILATOR IS IN THE FOLD POSITION.
fully spread conditions, spread command, and
At the same time, the bladefold control panel logic
pitch lockpin IN condition for each blade. At this
point, a relay actuates that pulls out the pitch
circuits receives a ground signal.
With the main rotor blades properly folded,
lockpin in each blade pitch control horn.
Simultaneously, a signal goes to a control panel
the bladefold control panel logic circuitry causes
spread complete logic circuit. This circuit actuates
the SPREAD INCOMPLETE caution capsule to
a 2-second time-delay relay. The relay shuts off
light under the following conditions:
hydraulic pressure to the pilot-assist servos and
Power goes to the fold or spread relays
provides a logic signal to the DAFCS computer.
without being commanded by the blade-
The logic signal to the DAFCS computer tells
fold control panel.
the computer to update flight control position
information from the transducers for 2 seconds.
Pylon or stabilator panel spread but not
This is accomplished when one stage of hydraulic
pressure is off, preventing preloading of the flight
controls. Any preloading of the controls would
Tail rotor blade positioner actuator
cause an error in position information to the
extends with the pylon in the flight
After the 2-second delay, the computer blinks
the RDR ALT push-button legend on the AFCS
CONTROL panel. This informs the operator that
the computer has accepted the flight control
REVIEW SUBSET NUMBER 12
position update. The computer will place the flight
controls in the new memorized position during the
Q1. In the H-60 bladefold system, the
next fold cycle.
transmission low oil pressure relay is
energized by a
PYLON AND STABILATOR FOLD
The first step in manually folding the pylon
is to complete bladefold operation. By doing this,
Q2. When the rotor head is on the insulated area
you prevent rotor blade and pylon damage.
between index drive slip ring segments 180
The crack open switch receives 28 Vdc, which
degrees from the index position, in what
direction will the rotor head travel towards
comes through contacts of the weight-on-wheels
relay. When the pylon opens about 5 degrees, the
crack open switch applies power to the tail rotor
blade positioner actuator. The actuator extends,
indexes, and gust locks the tail rotor. It extends
until the internal extend limit switch disconnects
Q3. During bladefold operations, if one blade
power. At the same time, another internal switch
fails to fold, will the other blades fold?
applies an actuator extended signal to the
bladefold control panel logic circuits.
If main bladefolding is operating at the same
time as pylon folding, the actuator extended signal
Q4. During blade spread operations, the
stops main fold. This prevents the main blades
actuators run in the fold condition after
from striking the pylon.
lockpin position switches activate to
Two stabilator lockpin switches close when the
stabilator locks in the flight (spread) position. This
applies 28 Vdc to the automatic engagement
circuit in the stabilator amplifier.
With the stabilator lockpin switches in
nonflight position, power is removed from the
Q5. During pylon and stabilator fold, at what
No. 1 and No. 2 stabilator amplifier auto engage
point does the crack open switch power the
circuitry. The auto engage circuitry engages when
tail rotor blade position actuator?