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.
g. Landing Gear Alternate Extension. An
ALTERNATE EXTENSION, is located on the floor
between the crew seats. Manually pumping the lever
lowers the landing gear. The hydraulic pump, which is
utilized to manually lower the gear, is located under
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
If for any reason the three green GEAR
DOWN indicator lights do not illuminate
(e.g., in case of an electrical system
failure), continue pumping until sufficient
resistance is felt to ensure that the gear is
down and locked. Do not stow the hand
pump handle. Stowing the handle will
release hydraulic pressure. If the three
GEAR DOWN indicator lights are not
illuminated, the landing gear downlocks
pressure may be the only thing holding the
landing gear down.
To engage the system, pull the LANDING GEAR
RELAY circuit breaker, located on the pilot's subpanel,
and ensure that the LDG GEAR CONTROL 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
DOWN indicator lights
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 gear, ensure that the extension lever is in the
full down position prior to stowing the lever in the
retaining clip. When the lever is stowed, an internal
relief valve is actuated to relieve the hydraulic
pressure in the pump.
After a practice alternate extension, stow the
extension lever, reset the LANDING GEAR RELAY
circuit breaker, and retract the gear in the normal
manner with the landing gear control handle.
h. 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.
i. Nose Wheel Steering System. The aircraft
is maneuvered on the ground by the nose wheel
steering system. Direct linkage from the rudder pedals
to the nose wheel steering linkage allows the nose
wheel to be turned 12° to the left of center or 14° to
the right. When rudder pedal steering is augmented
by main wheel braking action, the nose wheel can be
deflected up to 48° either side of center. Shock loads,
which would normally be transmitted to the rudder
pedals, are absorbed by a spring mechanism in the
steering linkage. Retraction of the landing gear
automatically centers the nose wheel and disengages
the steering linkage from the rudder pedals. Refer to
applications will cause a loss of braking
efficiency, and may cause brake failure,
wheel failure, tire blowout, or destruction
of wheel assembly by fire.
j. Wheel Brake System. The main wheels are
equipped with multiple-disc hydraulic brakes actuated
by master cylinders attached to the toe brake sections
of the rudder pedals. Brake fluid is supplied to the
system from a reservoir in the nose compartment.
Braking is permitted from either set of rudder pedals.
No emergency brake system is provided.
2-8. PARKING BRAKE.
Dual parking brake valves are installed below the
simultaneously by pressing both brake pedals in either
cockpit position to build up pressure, then pulling out
the handle, placarded PARKING BRAKE, on the
pilot's subpanel. Pulling the handle full out sets the
check valves in the system and any pressure being
applied by the toe brakes is maintained. The parking
brake is released when the brake handle is pushed in.
The parking brake may be set from either the pilot's or
copilot's position. The parking brake shall not be set
Blakey Departs AIA
[Avionics Today 02-24-2015] Marion Blakey will be leaving her post...