Eads Eurocopter BO 105 CBS-5 - Flight Control System; Cyclic Stick; Collective Lever; Directional Control Pedals

EUROCOPTER
FLIGHT MANUAL BO 105 CB-5/CBS-5
7 - 24
MANUFACTURER’S DATA
Rev. 0
7.9 FLIGHT CONTROL SYSTEM (see Fig. 7-13)
The flight control system comprises a cyclic stick, a collective lever, and directional pedals
to produce control inputs to the main rotor hydraulic servo actuators and tail rotor pitch
change links.
Cyclic and collective servo actuator control inputs are combined by mixing levers and fur-
ther transmitted to a swashplate. The swashplate changes the linear motion from the mix-
ing levers to rotating motion and conveys pitch changes to the four main rotor blades.
Yaw control inputs are transmitted to the tail rotor sliding sleeve. The pitch of each blade
changes when directional control inputs cause the nonrotating portion of the sliding sleeve
to act upon the rotating portion. Pitch links between the sliding sleeve rotating portion and
the pitch horn of each blade cause collective pitch angle changes of the tail rotor blades.
7.9.1 Cyclic Stick (see Fig. 7-13 and 7-14)
The cyclic stick is used to induce helicopter movements about the pitch and roll axes. The
basic cyclic stick grip has switches for RPM-warning audio cutoff, cyclic control force trim-
ming, and radio and internal communications microphone keying.
7.9.2 Collective Lever (see Fig. 7-13 and 7-14)
The collective lever provides a means of adjusting pitch angle of the main rotor blades
and fuel flow metering requirements of the power turbine. A switch panel at the end of the
lever has several switches installed, however, only the 4-way ENGINE TRIM switch and,
on S-751 and subsequent, the LANDING LIGHT switches are active on the standard
model. A friction adjustment at the base of the lever is used to prevent the collective pitch
setting from moving when the lever is released.
7.9.3 Directional Control Pedals (see Fig. 7-13)
The directional control pedals are used to induce helicopter movement about the yaw
axis. The pedals are adjustable fore-aft by use of a knob located aft of and between the
pedals.
7.9.4 Cyclic Trim System (see Fig. 7-13 and 7-14)
The position of the cyclic stick may be electrically trimmed using the cyclic trim system. A
lateral and a longitudinal trim feel spring assembly, each with an electrical actuator, are
incorporated to produce artificial feel and cyclic control system trim. The spring assem-
blies will hold the cyclic stick in a neutral-feel trimmed position. Movement of the cyclic
stick will cause the spring assemblies to compress and provide feel to the controls. When
control pressure is released the cyclic will return to the neutral-feel position.