Rockwell Commander 112 - POWER PLANT

SECTION I
GENERAL
INFORMATION
MAINTENANCE MANUAL
ROCKWELL
COMMANDER
112/B/TC/TCA
pilot visibility during flight. The aft fuselage section,
extending from fuselage station 178.00 to 263.00, is
permanently secured to the center fuselage section
and provides structural attachment points for the em-
pennage flight surfaces and controls. This section
houses the battery, hydraulic power pack unit and
various control surface cables. The entire fuselage
is designed to assure a strong safety margin for all
flight conditions and to provide attaching structures
for the wing and empennage. Sturdy aluminum floor-
ing supported by longitudinal beams and bulkheads
extends
from the firewall aft through the baggage com-
partment. The center wing structure is attached to
the fuselage so
that part of the wing torque is absorbed
by the fuselage structure.
WING
Each wing is of an all-metal stressed-skin construc-
tion incorporating spars, formed ribs and an integral
fuel tank contained in a three- rib section, forward of
the
main spar. The main spar of each wing is joined
at the center of the fuselage with spar cap splices.
The wing is installed in the lower center fuselage
section and secured to the fuselage loadbearing
frames and fittings by bolts and nuts at stations
85.00, 123,00 and forward of station 148.00.
Access plates located at various points on the lower
skin of the wing provide access for inspection and
repair of the fuel system and the flight control cabling.
Landing
gear fitting/retraction mechanisms are in-
stalled in the basic wing structures to provide attach-
ment points for the main landing gear. An opening in
the inboard leading edge of each wing serves as a
ram air intake for the cabin ventilation system.. An
electrically operated wing flap is installed between
the fuselage and
aileron on each wing. The flaps are
attached to the aft wing spar by hinge assembliesQ
Extension and retraction of the wing flaps is controlled
by an electrically controlled jackscrew and torque tube
arrangement. Metal ailerons, extending outboard from
the flaps to wing station 189000, are attached to the
aft wing
spar by hinge assemblies.
EMPENNAGE
The empennage consists of the vertical and horizontal
stabilizers. The vertical fin assembly is made of two
separate components; an upper assembly which is
mated at the horizontal stabilizer, and a lower stub
assembly which is integral with the aft tailcone struc-
ture. A rudder control surface is attached to the ver-
tical stabilizer at two hinge points. A fiberglas
rudder cap contains provisions for mounting various
electronic antennas and the anti-collision beacon.
The horizontal stabilizer, consisting of a fixed and
movable
elevator surface, is attached to the lower
vertical stabilizer stub assembly. The horizontal
and vertical stabilizers both utilize stressed and
beaded skin
construction to provide maximum strength
with minimum structural components. The horizontal
surface is of single unit constructions with a fixed for-
ward surface and a hinged elevator control surface.
1-6
The elevator provides mounting attachment for a
fiberglass tip-fairing at each outboard end for stream-
lined appearance. The aft tailcone assembly is also
capped by a fiberglass stinger containing mounts for
a tail navigation light and lens assembly, and tail tie-
down ring mounted in the vertical fin portion of the
cap_ The rudder and elevators are controlled by a
cable and pulley system attached to the control sur-
face bellcrank or horn. Controllable trim tabs are
installed on the elevators. A ram air intake, reces-
sed into the center of the vertical stabilizer, pro-
vides maximum cool air for in-flight cabin ventilation.
AIRCRAFT SYSTEMS
HYDRAULIC SYSTEM
The landing gear system extension and retraction
actuators are operated by the aircraft hydraulic sys-
tem. Hydraulic fluid under pressure is supplied to
the
system by an electric hydraulic power pack unit
installed in the left forward area of the aft section_
A landing gear selector switch, mounted on the
instrument panel, controls the direction of fluid
flow
from the pump to permit gear retraction or
extension. An emergency extension system is
provided to operate the landing gear in the event the
hydraulic system malfunctions. The gear will drop
by gravity assisted by down springs. Other hydraulic
components use hydrauliC fluid but are not function-
ally associated with the primary hydraulic system.
These are the master brake cylinders, nose shimmy
dampener, nose and main gear struts and wheel
brakes. All of these components have self contained
reservoirs and are not dependent upon the main sys-
tem.
POWER PLANT
MODELS 112/B. A direct-drive 200-horsepower Lyc-
oming IO-360-C1D6 engine is used to power the air-
craft. The engine is a four-cylinder horizontally-
opposed air cooled engine which employs a wet sump
oil system and is equipped with fuel injection. Engine
shock
mounts, which dampen engine and propeller
vibration, support the engine on the welded tubular
engine mount bolted to the airframe firewall. On
Model 112, the engine is equipped with a Hartzell
HC-E2YR-1BF/F7666A all metal constant speed pro-
peller. The Model 112B aircraft is equipped with a
Hartzell HC-E2YR-1BF /F8467-7R 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 machine screws and is removed
only when removing the engine or performing mainte-
nance on the lower portion of the engine. The upper
segment containing the oil access door is held in place
to the lower segment by four Camioc latches and two
studs. Adjustable cowl flaps, located in the lower
segment of the engine cowl, control cylinder head
Copyright Commander Owners Group 2013 All Rights Reserved
**unofficial copy**