1. Initial Pilot Ground School
EC 130 B4
Initial Pilot Ground School
Chapter 8
Flight Controls
and Servo Controls

2. Chapter 8 - Flight Controls and Servo Controls
Main Rotor Controls …………...……………………….…………...….… 8.3
Cyclic Controls ……………………………………………….…………….. 8.5
Lever Support Brackets …………………………………………………… 8.8
Mixing Unit Accessories ……….………………...………………………. 8.10
Collective Twist Grips ……..…………..…………………………………
Twist Grip Warning Light ………………....……………………………… 8.16
Collective Controls ………………………………………………………… 8.17
Tail Rotor Controls …………………..……………………………………
Tail Rotor Potentiometer …………………………………………………. 8.24
Servo Controls …………………………...………..………………………
Servo Control Operation …………………..……………………………… 8.28
Limit Caution Light ………..…………………….…………………………. 8.35
Distribution Valve Operation - Seizure Sensing ………………………. 8.36
Servo Caution Light ………………………………………………………… 8.38
Servo Caution Light Summary ……………………………………………. 8.43
Review Questions …………………………………………………………
8.2

3. Main Rotor Controls Relay Lever Support Brackets Mixing Unit
MAIN ROTOR FLIGHT CONTROLS
GENERAL:
DESCRIPTION:
OPERATION:
Collective Control Rod
Longitudinal Control Rod
Longitudinal
Torque Tube
Lateral Control Rods
Collective Torque Tube
Lateral Synchronizer Rod
Longitudinal Control Rod
Lateral Control Rod
Longitudinal Bellcrank
Lateral Bellcrank
8.3

4. Main Rotor Controls Forward Fore & Aft Cyclic Lateral Cyclic
8.4
Main Rotor Controls
Forward
Fore & Aft Cyclic
Lateral Cyclic
Collective Pitch

5. Standard Cyclic Grip
8.5

6. Optional Cyclic Grip
8.6

7. Cyclic Friction
Pilot’s Side Only
8.7

8. Lever Support Brackets
Forward
Forward
Limit Light Switches
Forward
Collective Lever
L/H Lateral Relay
Longitudinal Relay
R/H Lateral Relay
8.8

9. Cyclic Compensator Spring
Forward
Forward
8.9

10. Mixing Unit Accessories Collective Compensator Spring
Anticipator
(XPC)
Forward
Collective Compensator Spring
8.10

11. Collective Twist Grips
Electrical unit
Copilot twist grip
Flight detent lock
Pilot twist grip
Rack gear (pilot module)
Copilot module rack and pinion gear
Friction adjustment
Ball-end rod
Input pinion (pilot module)
Torque tube between collective pitch levers
Cam
‘Flight’ Position
“TWIST GRIP” warning light microswitch
Idle detection microswitch
To FADEC
8.11

12. Landing Light Switch and
Collective Twist Grip
Hoist Cable Cutter
Fixed Landing Light
Float
Arming
Switch
Landing Light Switch and
Swivel Button
VEMD Scroll Switch
8.12

13. The “TWIST GRIP” Throttle - can be considered as a rolling switch
The “TWIST GRIP” Throttle - can be considered as a rolling switch....you are either in the Ground Idle position (NG approx. 67%), or the Flight position. There is no modulation of the fuel, therefore, the throttle can not be used to control yaw during an in-flight (cruise) emergency. The throttle is used for starting and shutdown (IDLE), to simulate engine failures, and for hovering tail rotor failures.
8.13

14. (spring loaded to “Flight” position) Out of ‘Flight’ Position Switch
Twist Grip Components
The total ‘throw’ between the idle position and the flight position is approximately 800 of travel.
There are no mechanical linkages between the throttle and the fuel control, only microswitches.
Idle Detection Ramp
Return Coil
Spring
(spring loaded to “Flight” position)
Idle Switch
TWT GRIP
Out of ‘Flight’ Position Switch
8.14

15. Twist grip outside flight position
WARNING PANEL
CORRECTIVE ACTIONS
TWT GRIP
Twist grip outside flight position
Flight Manual - Emergency Procedures - Page 3-13
8.15

16. Twist grip outside flight position
WARNING PANEL
CORRECTIVE ACTIONS
TWT GRIP
Twist grip ……………INCREASE to
“FLIGHT” position
Twist grip outside flight position
CONTINUE FLIGHT
Flight Manual - Emergency Procedures - Page 3-13
8.16

17. Collective Friction
Friction Wheel
Friction Pads
Friction Plate
8.17

18. Collective Friction Components
Forward
Friction Plate
Friction Pads
8.18

19. Collective Locking
The collective incorporates a sliding sleeve. When moved FWD at flat pitch the collective is locked down. To release the collective, push down on the collective, and the slider will spring back unlocking the collective.
Forward
8.19

20. Collective Stop Bolts are used to adjust the autorotative NR.
Forward
8.20

21. Flexible-Ball Cable from T/R pedals to fenestron.
Tail Rotor Controls
Flexible-Ball Cable attaches to Control Rod which connects to the Pitch Control Lever.
Flexible-Ball Cable from T/R pedals to fenestron.
TAIL ROTOR CONTROLS
8.21

22. Tail Rotor Pedals
Secondary Stops
8.22

23. Tail Rotor Pedal Components T/R Pedal Friction Device
Potentiometer
(DDN)
8.23

24. Why does the EC-130 have a T / R Pedal Potentiometer?
Neutral
Left Pedal
Right Pedal
104
103
102
101
100 99 98
400 NR
NF %
Hp > 15,000 ft
Hp = 10,000 ft
Hp = 5000 ft
386 NR
Hp < 1000 ft
Pedal Position (DDN) %
It provides Noise Reduction by varying rotor RPM
8.24

25. Aft Tail Rotor Controls
8.25

26. Servo Controls
Three
Double-Cylinder
Servo Actuators
8.26

27. Servo Actuators Upper body (LH hydraulics) Servo Input Lever
Attaching Point
Lower body
(RH hydraulics)
8.27

28. Servo Control Operation
GENERAL:
DESCRIPTION:
OPERATION:
EXTENSION
RETRACTION
8.28

29. Distributor Valve - Normal Operation
The servos use a dual rotary distributor valve to channel hydraulic fluid to and from the servo. The primary distributor valve (#1) moves freely within the back-up valve (#2).
Should there be a seizing between the primary and backup valves, they will move together as a single unit, continuing to supply pressurized fluid and return.
When this occurs (not as a result of a hydraulic failure), a SERVO caution light will illuminate. #1 #2
DISTRIBUTER VALVE NORMAL OPERATION:
8.29

30. Distributor Valve - Normal Operation
Inputs are being made through the input lever (1).
The primary valve (2) moves freely within the secondary valve (3), which is held in place by a three ball bearing cap (4), a lever and a spring assembly (5). 4 2 5 3
DISTRIBUTER VALVE NORMAL OPERATION 1 1
8.30

31. If heavy flight loads are encountered, the amount of force the hydraulic system can boost may be exceeded, therefore the floating arm is forced down against the microswitch and the LIMIT caution light illuminates.
LIMIT
Right Lateral Servo
The other cause of the LIMIT light would be excessive movement of the cyclic beyond allowable limits, again causing a microswitch to depress with the LIMIT caution light illuminating.
LIMIT LIGHT OPERATION
Longitudinal Load
Switches
8.31

32. LIMIT Main servo unit max load reached or
WARNING PANEL
CORRECTIVE ACTIONS
LIMIT
Main servo unit max load reached or
Max rotor head stress reached
Flight Manual - Emergency Procedures - Page 3-21
8.32

33. LIMIT In high speed cruise flight or steep maneuvers :
WARNING PANEL
CORRECTIVE ACTIONS
In high speed cruise flight or
steep maneuvers :
1. Collective ……………. Reduce power
2. Cyclic ………………… Reduce speed or
load factor.
LIMIT
Main servo unit max load reached or
Max rotor head stress reached
Flight Manual - Emergency Procedures - Page 3-21
8.33

34. LIMIT In high speed cruise flight or steep maneuvers :
WARNING PANEL
CORRECTIVE ACTIONS
In high speed cruise flight or
steep maneuvers :
1. Collective ……………. Reduce power
2. Cyclic ………………… Reduce speed or
load factor.
At rearward speed or hovering in a high tail wind:
1. Cyclic ………………… Reduce rearward
speed
Reduce tailwind
component.
LIMIT
Main servo unit max load reached or
Max rotor head stress reached
Flight Manual - Emergency Procedures - Page 3-21
8.34

35. LIMIT In high speed cruise flight or steep maneuvers :
WARNING PANEL
CORRECTIVE ACTIONS
In high speed cruise flight or
steep maneuvers :
1. Collective ……………. Reduce power
2. Cyclic ………………… Reduce speed or
load factor.
At rearward speed or hovering in a high tail wind:
1. Cyclic ………………… Reduce rearward
speed
Reduce tailwind
component.
LIMIT
Main servo unit max load reached or
Max rotor head stress reached
CONTINUE FLIGHT
Flight Manual - Emergency Procedures - Page 3-21
8.35

36. Distributor Valve Operation
Seizure Sensing
If a seizure within the servo occurs, then the primary rotary valve and the secondary rotary valve will move as one. The rotation of the secondary valve causes the ball bearings to rise up on a ridge, displacing a lever against a microswitch, which causes the SERVO caution light to illuminate.
DISTRIBUTER VALVE SEIZING SENSING
SERVO
8.36

37. Jamming of a distributor valve on a main servo unit
WARNING PANEL
CORRECTIVE ACTIONS
SERVO
Jamming of a distributor valve on a main servo unit
Flight Manual - Emergency Procedures - Page 3-15
8.37

38. Jamming of a distributor valve on a main servo unit
WARNING PANEL
CORRECTIVE ACTIONS
SERVO
CONTINUE FLIGHT
Jamming of a distributor valve on a main servo unit
Flight Manual - Emergency Procedures - Page 3-15
8.38

39. Servo Test Switch
8.39

40. ON THE GROUND TEST (NO PRESSURE) - when depressing the servo pushbutton on the center pedestal, the SERVO light will extinguish.
SERVO
SERVO
ON THE GROUND TEST NO PRESSURE
8.40

41. TEST WITH HYDRAULIC SYSTEM PRESSURIZED - pressing the servo pushbutton will illuminate the SERVO light on the CWP.
SERVO
TEST HYDRAULIC SYSTEM PRESSURIZED
8.41

42. SEIZING OF DISTRIBUTOR VALVE - the seizing of the rotary distributor valve (primary to secondary) will cause the microswitch to move, illuminating the SERVO light.
SERVO
SEIZING DISTRIBUTER VALVE
8.42

43. Servo Light Summary The light will extinguish during the ground SERVO
test before start with no hydraulics applied.
The light will illuminate during ground test
after start-up with hydraulics applied.
[ Whether pressurized or un-pressurized, pressing the
“Servo Test” button changes the status of the
light when everything is working correctly.]
Seizure of any one of the six servo distributor valves
will cause only the light to illuminate.
SERVO
SERVO
SERVO
8.43

44. Review Questions
8.44

45. 68. What are the main components in the
main rotor / tail rotor flight system controls?
B. Push-pull tubes and bell cranks / flexball
cable and a push-pull tube.

46. 69. What is the purpose of the mixing unit?
D. Sum (add) the cyclic inputs with the
collective inputs.

47. 70. Which main rotor servo moves to pitch the aircraft nose up or down?
A. The left forward servo.

48. 71. What adjustments need to be made for an autorotation rpm change IAW Section 8 of the Flight Manual?
D. Low pitch adjustment stop / lock strip
(down-stop bolt).

49. 72. How many hydraulic servos are utilized in the EC130 B4?
A. Three dual bodied servos.

50. 73. When the pilot inputs control forces through the flight controls to the servo stops, where does the distributor valve stop?
D. Hydraulic zero.

51. 74. What are the separate aerodynamic functions of the three servos?
B. Right lateral (roll), left lateral (roll),
and pitch (longitudinal).

52. 75. What is the upper rod end bearing of each main servo attached to?
D. Non-rotating swashplate.

53. 76. What is the lower rod end bearing of each main servo attached to?
A. Conical housing of the main gear box.

54. 77. What happens to the SERVO light when the SERVO TEST pushbutton on the console is pressed & everything is working correctly?
C. The status (illuminate / extinguish) of the
SERVO caution light will change.

55. 78. On the tail rotor servo, what attaches to the pilot control input lever and provides input from the yaw pedals?
C. There is no tail rotor servo on this aircraft.

56. What type of control linkage interconnects the cyclic, collective, and the swashplate?
D. Rigid control tubes.

57. 80. What component allows the collective and cyclic to interface without interference?
A. The mixing unit.

58. Initial Pilot Ground School
EC 130 B4
Initial Pilot Ground School
End of Chapter 8
Flight Controls
and Servo Controls