Piper Aircraft Corporation Malibu Mirage PA-46-350P, Airplane Maintenance Manual

Page: 779 / 1956

PAGE 1
Feb 28/07 4C21
32-00-00
PIPER AIRCRAFT, INC.
PA-46-350P, MALIBU MIRAGE
MAINTENANCE MANUAL
GENERAL
This chapter provides instructions for the overhaul, inspection and adjustment of the various components
of the landing gear and brake systems. Also included are adjustments for the electrical limit, safety and
warning switches.
1. Description and Operation
This airplane is equipped with a retractable tricycle air-oil strut type landing gear which is hydraulically
operated by an electric hydraulic pump. A selector handle or switch on the instrument panel to the left of
the control quadrant is used to select gear UP or DOWN positions.
Gear positions are indicated by a display of three green lights (for gear down and locked) located above
the gear selector and a red warning light (for gear-in-transit or gear-unsafe conditions) in annunciator
panel. There is no separate light to indicate that all gears are fully retracted other than all gear lights
being out.
The landing gear swings to the down position and each actuator extends to its locked position, a switch
located on each actuator activates to indicate by a green light that the individual gear is safely down and
locked. When the gear begins to retract and the hydraulic actuators unlock, the down limit switch
actuates to the NC circuit and, in series with the NC circuit of the up limit switch, allows the gear unsafe
light to come on. The gear unsafe light will remain on until the gear is up and all up limit switches are
actuated to their normally open (NO) circuit.
A gear warning horn will sound when power is decreased to 15 ± 1 In. Hg. manifold pressure unless all
three gears are down. This horn will also sound if the flaps are extended beyond approach position if the
gears are not down and locked.
The red gear unsafe light also operates simultaneously with the warning horn. Their primary purpose is
to give warning when power is reduced below 15 ± 1 In. Hg. manifold pressure and the landing gear has
not reached the down and locked position. This circuit is controlled by three (3) paralleling down limit
switches connected in series with a throttle switch located in the control quadrant (see 91-32-60 for
electrical schematic).
Each landing gear is retracted and extended by a single hydraulic locking cylinder attached to the oleo
strut housing. As the gears retract, doors enclose each gear through mechanical linkage. The gears are
held in their up position by hydraulic pressure on the cylinder.
A hydraulic system modification and power pak upgrade provides a modification to the hydraulic power
pak electrical system which will, under certain conditions, bypass the low pressure switch in the event
the switch fails to operate.
The gear system has a free fall secondary extension system which consists of a valve that is controlled
from the panel. A down spring is incorporated in the nose gear to overcome air loads resisting gear
extension.
The nose gear is steerable through a 60 degree arc by use of the rudder pedals. As the gear retracts,
the steering linkage becomes separated from the gear so that rudder pedal action with the gear
retracted is not impeded by the nose gear operation. The nose gear rotates 90° to stow in the horizontal
position underneath the luggage compartment floor. A steering bungee is also incorporated in the nose
wheel steering mechanism.
The main wheels are equipped with dual piston, single-slotted disc hydraulic brakes.
The parking brake is set by depressing both toe brakes and setting a push-pull valve lock on the
instrument panel.