Piper AZTEC D PA-23-250 Owner's Handbook Manual page 24

THE PIPER AZTEC "D"
event of failure of the hydrau-
lic pump on the left engine.
To operate the emergency
pump, the handle should be
extended to its full length by
pulling it aft and positioning
the gear control as desired.
Approximately fifty strokes
are required to raise or lower
the landing gear.
For emergency extension
of the landing gear,
if
failure
of the hydraulic system should
occur due to line breakage or
SECTION II
Anti-Retraction Valve
hydraulic control unit malfunction, an indepement
co
2 system
is available to extend the landing gear.
Included on the left main gear is an oleo actuated by-pass
valve which makes it impossible to retract the landing gear
while the weight of the airplane is on the gear. This valve is
open when the oleo strut is compressed and by-passes all hydrau-
lic fluid, on the pressure side of the system, to the return side,
preventing any pressure build-up in the retraction system. When
the oleo strut is extended as in flight, or when the aircraft is on
jacks, the valve is closed permitting the system to operate in
the normal manner.
CONTROL SYSTEM AND SURFACES
Dual flight con. t rols are provided in the Aztec as standard
equipment. All controls are light, yet solid and effective in
flight at all speeds down through the stalling speed. The nose
wheel is steerable on the ground . through the rudder pedals.
All control surfaces are cable controlled and are conven-
tional sheet metal structures, fitted with aluminum hinges
and needle bearings. The flaps are actuated by a hydraulic
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