EC 130 B4 Initial Pilot Ground School Chapter 9 Hydraulic System

Chapter 9 - Hydraulic System Hydraulic System - General …...……………………….…………...….…9.3 Technical Characteristics ….……………………………….……………..9.5 Hydraulic System Schematic ……..………………………………………9.6 Hydraulic Reservoirs …………....………………...……………………….9.7 Hydraulic Manifolds ………..…………..………………………………… Hydraulic Filter Assembly ………………....………………………………9.13 Servo Actuators …………..…………………………………………………9.14 Normal Operation ……...……………..…………………………………… Lower System Failure ……...……………………………………………….9.16 Upper System Failure …………………...………..……………………… Hydraulic and Servo Caution Lights ……..………………………………9.22 Hydraulic Caution Light Summary …………...………………………….9.26 Review Questions …………………………………………………………

Hydraulic System - General Dual Hydraulic Systems are totally isolated from each other Three dual-body tandem mounted servo controls Aft pump is belt driven from the engine to MGB driveshaft Forward pump directly driven from MGB Aft pump is belt driven from the engine to MGB driveshaft Tandem Reservoirs 9.3

General Overview of the Hydraulic System: Dual hydraulic systems are totally isolated from each other Dual hydraulic systems are totally isolated from each other RH - pressure to lower servo bodies RH - belt driven pump (as in AS350) RH - reservoir is the forward of the two tanks LH - pressure to upper servo bodies LH - direct drive pump from MGB bevel gear LH - reservoir is the rear of the two tanks NO accumulators in the EC130 B4 hydraulic system NO accumulators in the EC130 B4 hydraulic system Tail rotor system is not boosted - there is no servo Tail rotor system is not boosted - there is no servo Should either system fail, the flight controls remain boosted Should either system fail, the flight controls remain boosted from the other system for continued normal flight from the other system for continued normal flight Dual body, tandem mounted main servos Dual body, tandem mounted main servos Common control input from flight controls Common control input from flight controls Rotary distribution valves Rotary distribution valves 9.4

Hydraulic fluid is routed through the conical portion of the transmission housing for pre-heating purposes. Technical Characteristics MIL H5606 fluid NOT certified 9.5

RH LH FWD AFT Hydraulic System Schematic 9.6

Hydraulic Reservoirs Rear Reservoir Front Pump L/H Manifold Upper Bodies Front Reservoir Rear Pump R/H Manifold Lower Bodies 9.7

Left Hand / Upper System Pump Forward 9.8

Right Hand / Lower System Pump 9.9

Regulation Valve 35 Bars Pressure Switch < 20 Bars Filter 3 Micron Clogging Indicator > 2.7 Differential Pressure Note: Both units are identical Hydraulic Manifolds 9.10

L/H Hydraulic - Upper System Manifold “Pop-Out” Clogging Indicator is here. 9.11

R/H Hydraulic - Lower System Manifold “Pop-Out” Clogging Indicator is here. 9.12

Hydraulic Filter Assembly “Popped”IndicatorButton with Clogging Indicator 3 Micron with No Bypass 9.13

ServoActuators Upper body (LH hydraulics) Servo Input Lever Attaching Point Lower body (RH hydraulics 9.14

Normal Operation 9.15

Belt Driven Lower System Failure RH 9.16

LH Upper System Failure MGB Driven 9.17

CORRECTIVE ACTIONS WARNING PANEL Flight Manual - Emergency Procedures - Page Loss of hydraulic pressure in one circuit. + SERVO HYDR

CORRECTIVE ACTIONS WARNING PANEL Flight Manual - Emergency Procedures - Page Loss of hydraulic pressure in one circuit. Keep aircraft to a more or less level attitude Avoid abrupt maneuvers Maintain angle of bank lower than 30 0 Maintain IAS below 110 kt (or VNE if lower) Normal approach and landing + SERVO HYDR

CORRECTIVE ACTIONS WARNING PANEL Flight Manual - Emergency Procedures - Page Loss of hydraulic pressure in one circuit. Keep aircraft to a more or less level attitude Avoid abrupt maneuvers Maintain angle of bank lower than 30 0 Maintain IAS below 110 kt (or VNE if lower) Normal approach and landing NOTE light may be on if RH circuit failed light may be on if RH circuit failed or during load factor maneuvers or during load factor maneuvers One remaining circuit allows continued safe flight and landing + [ Note: The Flight Manual is incorrect. “RH” should say “LH” ] SERVO HYDR LIMIT

CORRECTIVE ACTIONS WARNING PANEL Flight Manual - Emergency Procedures - Page Loss of hydraulic pressure in one circuit. Keep aircraft to a more or less level attitude Avoid abrupt maneuvers Maintain angle of bank lower than 30 0 Maintain IAS below 110 kt (or VNE if lower) Normal approach and landing NOTE light may be on if RH circuit failed light may be on if RH circuit failed or during load factor maneuvers or during load factor maneuvers One remaining circuit allows continued safe flight and landing + LAND AS SOON AS PRACTICABLE [ Note: The Flight Manual is incorrect. “RH” should say “LH” ] SERVO HYDR LIMIT

CORRECTIVE ACTIONS WARNING PANEL Flight Manual - Emergency Procedures - Page Loss of hydraulic pressure in one circuit. Keep aircraft to a more or less level attitude Avoid abrupt maneuvers Maintain angle of bank lower than 30 0 Maintain IAS below 110 kt (or VNE if lower) Normal approach and landing NOTE light may be on if RH circuit failed light may be on if RH circuit failed or during load factor maneuvers or during load factor maneuvers One remaining circuit allows continued safe flight and landing + LAND AS SOON AS PRACTICABLE CAUTION Under high load factor, servocontrol reversibility can be encountered. [ Note: The Flight Manual is incorrect. “RH” should say “LH” ] SERVO HYDR LIMIT

Why does the light illuminate with a Left Hand hydraulic system failure? a Left Hand hydraulic system failure? 9.23 LIMIT Left Hand Hydraulic Fluid is used to support the upper Right Hand roll servo rod end bearing. When the Left Hand Hydraulic system fails with the rotor turning, the rod end bearing drops against the limit light switch, thereby activating the light. LIMIT LIMIT

SERVO Each hydraulic system (LH for upper bodies, RH for lower bodies) provides pressure to keep a plunger and spring from displacing the secondary distributor valve, causing the SERVO caution light to illuminate. SERVO SERVO Why does the light illuminate with a hydraulic failure? 9.24

Should a hydraulic failure occur, the loss of pressure in the system will allow for the plunger to move due to a spring force, displacing an arm attached to the secondary rotary valve, causing the SERVO light to illuminate on the CWP (in addition to the HYDR light). Hydraulic Failure 9.25 Seizure of at least one of six distributor valves illuminates the SERVO light. SERVO SERVO

Loss of hydraulic pressure in the lower system will Loss of hydraulic pressure in the lower system will cause the HYD P light and SERVO light to illuminate. cause the HYD P light and SERVO light to illuminate. Loss of hydraulic pressure to the upper system will Loss of hydraulic pressure to the upper system will cause the HYD P, SERVO & LIMIT lights to cause the HYD P, SERVO & LIMIT lights to illuminate. illuminate. Hydraulic & Servo Light Summary 9.26 SERVOHYDR LIMITSERVOHYDR

ReviewQuestions 9.27

81. The hydraulic fluid tubing is routed through a certain component just prior to going to the servos. What component is this, and why is the fluid routed through it? C. Conical housing of the transmission; to pre-heat the hydraulic fluid. pre-heat the hydraulic fluid.

82. Does the hydraulic filter have by-pass capability? B. No

83. What cockpit indicators notify the pilot of a loss of hydraulic pressure in one circuit? D. HYDR light and a SERVO light illuminating. If the LH circuit has failed you will also If the LH circuit has failed you will also have the LIMIT light illuminated. have the LIMIT light illuminated.

84. When experiencing a loss of hydraulic pressure in one circuit, which of the following landing recommendations is indicated in the emergency procedures? C. LAND AS SOON AS PRACTICABLE

EC 130 B4 Initial Pilot Ground School End of Chapter 9 Hydraulic System