the barricade; a pressure gauge for the barricade
hydraulic system; a control lever to raise or lower the
barricade stanchions; push buttons to raise, lower, or
stop the retractable sheaves; an indicator light to
indicate their position; a battery position indicator light
for the damper sheaves; and synchro receivers to
monitor settings on the aircraft weight selector unit of
each engine.
The deckedge control operator operates the
controls from the gallery walkway and is equipped with
sound-powered
phones
to
maintain
voice
com-
munications with the engine-room operator and
Pri-Fly.
RETRACTING VALVE
The retracting valve permits the controlled return
of fluid from the accumulator to the cylinder, thereby
returning the engine to the BATTERY position. The
general location of the retracting valve is shown in
figure 3-7.
The
retracting
valve
is
a
self-contained
poppet-valve assembly composed principally of a
housing, a plunger, an operating lever, a valve stem, and
a valve seat.
The retracting valve operates as a check valve
against the flow of fluid from the accumulator to the
engine cylinder. Fluid at accumulator pressure enters
the housing and bears on the stem in the direction that
would open the valve; however, the pressure also bears
against the base of the plunger, which tends to close the
valve. Since the area of the plunger end is greater than
that of the stem, the differential in force keeps the valve
closed.
The retracting valve has piping that provides
passage for engine fluid flow from the arresting engine,
by way of the retracting valve, to the cable anchor
dampers. A discharge port is provided where the
retracting valve and pressure valve body are bolted
together to allow fluid flow from the accumulator or
fluid cooler into the main engine cylinder during
retraction.
Retracting Valve Body
The retracting valve body is a hollow steel casting
with an inlet port, connected by piping to the engine
accumulator/fluid cooler manifold, a discharge port
that is flanged and bolted to the engine cylinder outlet
elbow, and a port connected by piping to the cable
anchor dampers.
3-10
TO DECKEDGE
CONTROL
LOCK NUTS
TO ACCUMULATOR
V-RING
PACKINGS
STEM
TO ENGINE
CYLINDER
SEAT
SHOCK
ABSORBER
DECKEDGE
CONTROL
ABEf0307
Figure 3-7.—General location of the retracting valve.
