Technical data

13773-001
27-20
Page 1
RUDDER AND YAW TRIM SYSTEM
1. DESCRIPTION
This section describes that portion of the flight control system which controls the position and movement of
the rudder. Included are; rudder system rigging, rudder pedal assembly, pulleys, cables and bellcranks,
rudder-aileron interconnect, and yaw trim system.
Rudder control is transferred by conventional rudder pedals through to the forward pulley gang at the bot-
tom of the center console. From the pulley gang, the single cable system is routed under the cabin floor to
the rudder-aileron interconnect, through to rudder-elevator pulley gang under the baggage floor, and finally
to the rudder actuation pulley. The rudder and elevator control system utilize separate pulleys which mount
to a shared pulley-gang bracket mounted inside the empennage. The rudder actuation pulley drives a
push/pull rod attached to the rudder bellcrank which is bolted directly to the rudder. Each set of pulleys has
a cable retainer to prevent fouling. Adjustable control stops at the rudder actuation pulley limit control sur-
face travel. Two springs attached to the rudder assembly and firewall provide rudder system interconnec-
tion and determine system cable tension.
The yaw trim system employes an electric trim tab. Neutral rudder position is held by a ground-adjustable
spring cartridge which bolts to the left rudder pedal torque tube and center console assembly. The car-
tridge is a captured compression spring that provides a centering force regardless of the direction of con-
trol surface deflection.
2. MAINTENANCE PRACTICES
WARNING:
A system rigging Inspection/Check must be performed after loosening any flight con-
trol cable to assure proper control surface operation. Refer to the appropriate control
system’s rigging procedures for the Inspection/Check maintenance practices.
A. Rudder System Cables (See Figure 27-201)
(1) Removal - Rudder System Cables
(a) Acquire necessary tools, equipment, and supplies.
(b) Remove right mid console trim panel. (Refer to 25-10)
(c) Remove passenger seats. (Refer to 25-10)
(d) Remove carpet and access panels CF3C, CF4C, and CF5. (Refer to 6-00)
(e) Disconnect rudder/aileron interconnect bungee from RH rudder cable. (Refer to 27-20)
(f) Remove empennage pulley gang. (Refer to 27-20)
(g) Remove cotter pin and washer securing pulley guard pin to rudder-elevator pulley gang
bracket and remove pin.
(h) Remove cotter pins and washers securing pulley guard pins to forward pulley gang bracket
and remove pins.
Note: To facilitate cable routing during installation, attach string to end of cables
prior to removing from airplane.
(i) Remove cotter pins, washers, nuts, and bolts securing rudder cables to rudder pedal
torque tubes. Attach string to ends of forward rudder cables.
Description P/N or Spec. Supplier Purpose
String - Any Source Cable Routing
31 July 2001