AIRCRAFT AND SYSTEMS DESCRIPTION AND OPERATION
Section I. AIRCRAFT
The purpose of this chapter is to describe the
aircraft and its systems and controls which contribute to
the physical act of operating the aircraft. It does not
contain descriptions of avionics or mission equipment,
covered elsewhere in this manual. This chapter
contains descriptive information and does not describe
procedures for operation of the aircraft. These
procedures are contained within appropriate chapters in
the manual. This chapter also contains the emergency
equipment installed. This chapter is not designed to
provide instructions on the complete mechanical and
electrical workings of the various systems; therefore,
each is described only in enough detail to make
comprehension of that system sufficiently complete to
allow for its safe and efficient operation.
The RC-12G is a pressurized, low wing, all
metal aircraft, powered by two PT6A-41 turboprop
engines (fig. 2-1 and 2-2), and has all weather
capability. Distinguishable features of the aircraft are
the slender, streamlined engine nacelles, mission
antennas, wing tip pods, a T-tail and a ventral fin below
the empennage. The basic mission of the aircraft is
radio reconnaissance. Cabin entrance is made through
a stair-type door on the left side of the fuselage.
Overall aircraft dimensions are shown in figure
GROUND TURNING RADIUS.
Minimum ground turning radius of the aircraft is
shown in figure 2-4.
Maximum take of gross weight is 15,000
pounds. Maximum landing weight is 15,000 pounds.
Maximum ramp weight is 15,090 pounds. Maximum
zero fuel weight is 11,500 pounds.
EXHAUST DANGER AREA.
Danger area to be avoided by personnel while
aircraft engines are being operated on the ground are
depicted in figure 2-5. Distance to be maintained with
engines operating at idle are also shown. Temperature
and velocity of exhaust gasses at varying locations aft
of the exhaust stacks are shown for maximum power.
The danger area extends to 40 feet aft of the exhaust
stack outlets. Propeller danger areas are also shown.
LANDING GEAR SYSTEM.
The landing gear is a retractable, tricycle type,
electrically operated by a single DC motor. This motor
drives the main landing gear actuators through a gear
box and torque tube arrangement, and also drives a
chain mechanism which controls the position of the nose
gear. Positive down-locks are installed to hold the drag
brace in the extended and locked position. The down-
locks are actuated by overtravel of the linear jackscrews
and are held in position by a spring-loaded overcenter
mechanism. The jackscrew in each actuator holds all
three gears in the UP position, when the gear is
retracted. A friction clutch between the gearbox and the
torque shafts protects the motor from electrical overload
in the event of a mechanical malfunction. A 150-
ampere current limiter, located on the DC distribution
bus under the center floorboard, protects against
electrical overload. Gear doors are opened and closed
through a mechanical linkage connected to the landing
gear. The nose wheel steering mechanism is
automatically centered and the rudder pedals relieved of
the steering load when the landing gear is retracted.
Air-oil type shock struts, filled with compressed air and
hydraulic fluid, are incorporated with the landing gear.
Gear retraction or extension time is approximately six
Landing Gear Control Switch. Landing gear
system operation is controlled by a manually actuated,
wheel-shaped switch placarded LDG GEAR CONTR UP
DN, located on the left subpanel (fig. 2-6). The control
switch and associated relay circuits are protected by a
5ampere circuit breaker, placarded LANDING