Rockwell Commander 112 - FUEL SYSTEM; LANDING GEAR, WHEELS AND BRAKES

ROCKWELL
COMMANDER
112/B/TC/TCA
MAINTENANCE MANUAL
SECTION I
GENERAL
INFORMATION
temperature during flight. All engine accessories
except the alternator are attached to mounting pads
on the engine.
MODELS 112TC/TCA. A direct-drive 210-horsepower
Lycoming TO-3GO-C1A6D engine is used to .power the
aircraft. The engine is a four-cylinder horizontally-
opposed air cooled turbocharged engine which employs
a wet sump oil system. Engine shock mounts, which
dampen engine
and propeller vibration, support the
engine on the welded tubular engine mount bolted to
the airframe firewall. The engine is equipped with
a
Hartzell HC-E2YR-1BF /F8467-7R all metal con-
stant speed propeller. The engine cowling consists
of two fiberglass segments that are easily removed
for quick access to all parts of the engine. The
lower segment is attached to the forward fuselage
with screws and is removed only when removing the
engine or performing maintenance on the lower por-
tion of the engine. The upper segment containing the
oil check door is held in place to the lower segment
by four Camloc latches and two studs. Adjustable
cowl flaps, located in the lower segment of the engine
cowl,
control cylinder head temperature during flight.
All engine accessories except the alternator are at-
tached to mounting pads on the engine.
FUEL SYSTEM
Fuel is stored in the integral forward wing structure
• of each wing (wet wing fuel tanks) outboard of wing
station 82. 50 and extending to wing station 142. 40.
The Model 112 (Serial numbers thru 125) has a fuel
system capacity of 32 U. S. gallons per tank, usable.
The Model 112 (Serial numbers 126 thru 155) has a
fuel
system capacity of 34 U. S. gallons per tank,
usable. The Models 112 (Serial numbers 156 thru
499), 112B, 112TC and 112TCA has a fuel system
capacity of 24 U • S. gallons per tank, usable with
standard tanks installed, and 34 U. S. gallons per
tank usable with optional tanks installed. The fuel
tanks are serviced through filler ports located on top
of both wings. Fuel is supplied from the tanks through
the fuel selector valve to the fuel gascolator. From
the gascolator, fuel travels through the electrically
operated auxiliary fuel pump to the engine-driven fuel
pump.
The auxiliary fuel pump is used for engine
starting and also provides fuel pressure to the engine
in the event of an engine-driven fuel pump failure.
LANDING GEAR, WHEELS, AND BRAKES
The retractable tricycle landing gear is operated hy-
draulically. Should a failure occur in the hydraulic
system an emergency system is provided for emer-
gency extension of the gear. The gear is held in the
up pOSition by hydraulic pressure lock and will free-
fall to the down and locked poSition if normal hydraulic
system pressure is lost. Emergency extension of the
main gear is accomplished by placing the emergency
gear extension knob in the DOWN position to release
hydraulic fluid trapped in the uplock portion of actu-
ators. This bypasses hydraulic fluid directly to the
Change 1
hydraulic power pack reservoir allowing the gear to
drop by gravity, assisted by down springs. Mechani-
cally actuated landing gear doors enclose the main
gear struts within the Wing. The nose landing gear,
which retracts into a wheel well under the engine is
enclosed by mechanically operated wheel well doors
when the gear is retracted. The nose and main land-
ing gear wheels are machined castings, consisting of
two wheel
halves. The wheel halves are not inter-
changeable; but the complete wheel assemblies are
interchangeable according to wheel size. Disc type
hydraulic brakes, attached to the main landing gear,
are individually controlled by applying toe pressure
to the rudder pedals at either pilot position. A park-
ing brake, which operates from the master brake cyl-
inder, is engaged by applying toe pressure on the
rudder pedals and pulling out the PARK BRAKE con-
trol knob. The nose wheel steering system is tied to
the rudder trim system and operated by depressing
the rudder pedals. Initial depression of the pedal
starts the nose wheel turning toward the desired di-
rection, while further pedal pressure results in a
combination of
nose wheel steering and main wheel
braking to turn the aircraft.
FLIGHT CONTROLS
The aircraft is equipped with a dual flight control sys-
tem, which utilizes control columns, control wheels,
and rudder pedals to operate the primary flight control
suIiaces. Trim tabs, located on the elevators are
controlled by rotating the trim tab control wheel, lo-
cated in the center console. A fixed position ground
adjustable trim tab, is installed on the trailing edge of
the left aileron. The wing flaps are operated electric-
ally and controlled by a switch on the lower right side
of the instrument panel. An internal control lock,
which may
be installed in the control column, secures
the ailerons and elevators in the neutral position when
the aircraft is parked.
INSTRUMENTS
All instruments except magnetic compass and outside
air temperature gage are installed in the main instru-
ment panel and sub-panel areas, and are grouped ac-
cording to function and ease of surveillance. All pri-
mary flight and gyro instruments are installed in the
left side of the main instrument panel. Manifold pres-
sure and tachometer gauges are mounted in the lower
center area of the main panel and the remaining engine
instruments are grouped horizontally ac ross the left
instrument Sub-panel. Lighting for the instruments is
furnished by a combination of post lights and flood
lights. Optional navigation and communications equip-
ment
is located in the center and right side of the
main instrument panel.
HEATING AND VENTILATION
The forced air heating and ventilation system provides
heat and ventilation to the cabin area. Heat is obtained
1-7
Copyright Commander Owners Group 2013 All Rights Reserved
**unofficial copy**