KIAS) the landing gear warning system will be rearmed
if both power levers are advanced above 86% N1.
With the flaps beyond the APPROACH position,
the warning horn and landing gear switch handle
annunciators will be activated regardless of the power
setting. The horn cannot be silenced in this case, until
either the landing gear is lowered, or the flaps are
retracted to the UP or APPROACH position.
Landing Gear Warning Horn Test Switch.
The warning horn and gear handle annunciators can be
tested by placing the switch placarded STALL WARN
TEST OFF LDG GEAR WARN TEST to the LDG GEAR
WARN TEST position (fig. 2-5). The gear handle
annunciators will illuminate, and warning horn will
sound. Releasing the LDG GEAR WARN TEST switch
to the OFF position will extinguish the gear handle
annunciators, and silence the warning horn. The landing
gear warning horn circuit is protected by a 5-ampere
circuit breaker, placarded LANDING GEAR HORN,
located in the overhead circuit breaker panel (fig. 2-6).
Landing Gear Safety Switches. A safety
switch on each main landing gear shock strut controls
the operation of various aircraft systems that function
only during flight or only during ground operation.
These switches are mechanically actuated whenever the
main landing gear shock struts are extended (normally
after takeoff), or compressed (normally after landing).
The safety switch on the right main landing gear strut
deactivates the landing gear control circuits, cabin
pressurization circuits and the flight hour meter when
the shock strut is compressed. This switch also activates
a downlock hook, preventing the landing gear from
being raised while the aircraft is on the ground. The
hook, which unlocks automatically after takeoff, can be
manually overridden by pressing down on the red
button, placarded DOWN LOCK REL located adjacent
to the landing gear handle (fig. 2-5). If the override is
used, the landing gear warning horn will sound
intermittently and two, red, parallel-wired annunciators
located in the landing gear control switch handle will
illuminate, provided the battery switch is on. The safety
switch on the left main landing gear strut activates the
left and right engine ambient air shut-off valves when
the strut is extended.
Landing Gear Alternate Extension.
After an emergency landing gear
extension has been made, do not
move any landing gear controls, or
reset any switches or circuit breakers
until the aircraft is on jacks. The
failure may have been in the gear-up
circuit which could cause the gear to
retract while the aircraft is on the
An extension lever, placarded LANDING GEAR
ALTERNATE EXTENSION, is located on the floor
between the crew seats. A manual pumping action with
the handle lowers the landing gears. The hydraulic
pump utilized to manually lower the gear is located
under the floor.
To engage the system, pull the LANDING GEAR
CONTROL circuit breaker, located in the overhead
circuit breaker panel (fig. 2-6), and ensure that the LDG
GEAR CONTR handle is in the DN position. Remove
the extension lever from the securing clip and pump the
lever up and down until the three green GEAR DOWN
annunciators illuminate. As the handle is moved,
hydraulic fluid is drawn from the hand pump suction port
of the power pack and routed through the hand pump
pressure port to the actuators. After an alternate
extension of the landing gears, ensure the extension
lever is in the full down position prior to stowing the
pump handle in the retaining clip. When the pump
handle is stowed, an internal relief valve is actuated to
relieve the hydraulic pressure in the pump.
If for any reason the three green GEAR
DOWN indicators do not illuminate
(e.g., in case of an electrical system
sufficient resistance is felt to ensure
that the gear is down and locked. The
After a practice alternate extension, stow the
extension handle, reset the LANDING GEAR CONTROL
circuit breaker, and retract the gear in the normal
manner with the landing gear control handle.
Tires. The aircraft is equipped with dual 22
x 6.75 x 10, 8 ply rated, tubeless, rim inflation tires on
each main gear and a 22 x 6.75 x 10, 8 ply rated,
tubeless tire on the nose wheel.