Hydraulic Systems Introduction

Hydraulic Systems Introduction

• The aircraft has two independent hydraulic systems: primary and utility.
• Both systems are similar but not identical, with separate and shared functions.

Primary Hydraulic System

• Provides hydraulic pressure to the primary side of all four flight control servoactuators.
• Consists of a hydraulic pump, manifold, and servoactuators.
• The primary hydraulic pump is mounted on the left side of the transmission accessory gearbox.
• The pump is a constant pressure, variable displacement design, driven by the transmission accessory gear train.

Primary Hydraulic Manifold

• Stores, filters, and regulates the flow of hydraulic fluid.
• Has mechanical dirty filter indicators for visual inspection on both manifold pressure and return sides.
• The return filter has a bypass valve.

Hydraulic System Controls

• Operation of the hydraulic system is automatic except in emergency situations, tail wheel locking/unlocking, and rotor brake activation.
• Hydraulic system indications are displayed on the ENG and SYS pages.
• The primary hydraulic system failure will result in the loss of BUCS and SCAS functionality.

Tail Wheel Lock

• Utility hydraulic pressure is used by the tail wheel lock actuator to unlock the tail wheel.
• The tail wheel can be locked or unlocked from either crew station via the TAIL WHEEL panel or collective grip tail wheel button.

Hydraulic System Indications

• PRI/UTIL/ACC PSI: 0 - 6000 psi displayed in increments of 10.
• Yellow warning: 3410 - 6000 psi ≥ 5 seconds, red with box: ≥ 5 minutes.
• Red with box: 0-1250 psi.

Pneumatic Systems

• The IPAS (Integrated Pneumatic System) pressurizes, regulates, and distributes air to various systems.
• The primary pneumatic power source is dual engine bleed air.
• The secondary source is single engine bleed air.
• APU bleed air is used to start main engines during aircraft power-up.

IPAS Control

• Control of IPAS is an integrated function provided by mission processors and the Electrical Power Management System (EPMS).
• The A/C UTIL page and HIT page provide BLEED AIR 1 and 2 on/off buttons.

Helicopter Operations

• Establish and announce a forced landing or single engine flyaway plan when operating at an OGE hover
• Maintain ground track within 3 feet, constant rate of movement for existing conditions, and constant rate of turn during OGE hover

In-Flight Operations

• Maintain heading ±10 degrees, ground track alignment with minimum drift, and altitude ±100 feet
• Maintain airspeed ±10 knots and rate of climb or descent ±200 feet per minute (FPM)
• Maintain trim ±ball width and acknowledge low altitude warning audio

Crew Responsibilities

• Both crewmembers are responsible for performing crew coordination actions and announcing malfunctions or emergency conditions
• PC (Pilot Command) duties include briefing specific duties before entering the helicopter, maintaining airspace surveillance, and applying environmental considerations
• Copilot/Gunner (CPG) duties include assisting the PC and performing additional tasks as required

Hover Power Checks

• Initial hover power check should be completed at the beginning of the flight IAW Task 1038 (IGE power available and environmental conditions permitting)
• Hover power TQ (percent [%] TQ) baseline can be determined using PERF page (CUR, PLAN, or MAX mode) calculations
• Environmental and load considerations will be applied throughout the flight

Situational Awareness

• Situational awareness information will be provided to each crewmember through their individual HDUs
• PC will approve instances when it may be desired not to employ the HDU during the conduct of the mission or a specific flight maneuver

Altitude Definitions

• Minimum Safe Altitude (MSA) is defined as the minimum safe height above the surface or obstacles to which the helicopter can descend in a masked condition
• Minimum Maneuvering Altitude (MMA) is defined as the altitude above the mask or barriers at which the helicopter may safely hover### AH-64 MTL

Aviator (PI): Base Task Training

• Participate in a Crew Mission Briefing
• Plan a Visual Flight Rules (VFR) Flight
• Plan an Instrument Flight Rules (IFR) Flight
• Prepare a Performance Planning Card (PPC)
• Verify Aircraft Weight and Balance
• Operate Mission Planning System
• Perform Preflight Inspection
• Perform Before-Starting Engine through Before-Leaving Helicopter Checks
• Initiate Hot and High Dual Engine Training Mode
• Maintain Airspace Surveillance
• Perform Radio Communications Procedures
• Perform Ground Taxi Operations
• Perform Hovering Flight
• Perform a Visual Meteorological Conditions (VMC) Takeoff
• Navigate by Pilotage and Dead Reckoning
• Perform Fuel Management Procedures
• Perform a VMC Approach
• Perform Slope Operations
• Perform a Roll-On Landing
• Respond to Emergencies
• Perform Single-Engine Landing
• Respond to Engine Failure
• Respond to Dual Engine Failure
• Perform Stability and Command Augmentation System-Off/Backup Control System-On Flight
• Respond to Engine Overspeed-Underspeed Condition
• Perform Rolling Takeoff
• Perform Tactical Situation Display Operations
• Perform Basic Maneuvering Flight
• Perform Integrated Helmet and Display Sight System Video Adjustments and Boresight
• Perform Digital Communications Procedures
• Negotiate Wire Obstacles
• Operate Video Recorder
• Perform Instrument Takeoff (ITO)
• Perform Radio Navigation
• Perform Holding Procedures
• Perform Non-Precision Approach
• Perform Precision Approach
• Perform Unusual Attitude Recovery
• Respond to Inadvertent Instrument Meteorological Conditions (IIMC)
• Perform Refueling-Rearming Operations
• Perform Diving Flight
• Employ Aviator's Night Vision Imaging System
• React to Aviator's Night Vision Imaging System Failure
• Participate in a Crew-Level After Action Review
• Perform Night Vision System Operational Checks
• Perform Combat Maneuvering Flight
• Perform Target Handover
• Operate Infrared Laser Pointing Devices
• Perform Aerial Observation
• Perform Evasive Maneuvers
• Perform Actions on Contact

Tactical Training

• Perform Tactical Flight Mission Planning
• Operate Aircraft Survivability Equipment (ASE)
• Perform Target Store Procedures
• Perform Target Acquisition Designation Sight Sensor Operations
• Perform Fire Control Radar Operations
• Perform Electronic Countermeasures-Electronic Counter-Countermeasures Procedures
• Transmit Tactical Reports (Digital/Voice)
• Perform Terrain Flight Navigation
• Perform Masking and Unmasking
• Perform Firing Position Operations
• Perform Weapons Initialization Procedures
• Perform Firing Techniques
• Engage Target with Semi-Active Laser Hellfire Missile
• Engage Target with Radar Frequency Hellfire Missile
• Engage Target with Rockets
• Engage Target with Area Weapon System
• Perform Target Handover

Maintenance Test Pilot (MP): Maintenance Training

• Perform Prior to Maintenance Test Flight Checks
• Perform Maintenance Operational Check-Maintenance Test Flight
• Perform Interior Checks
• Perform Before-Starting Auxiliary Power Unit Checks
• Perform Starting Auxiliary Power Unit Checks
• Perform After-Starting Auxiliary Power Unit Checks
• Perform Starting Engine Checks
• Perform Engine Run-Up and Systems Checks
• Perform Before Taxi Checks
• Perform Taxi Checks
• Perform Baseline and Normal Engine Health Indicator Test
• Perform Before Hover Checks
• Perform Hover Checks
• Perform Hover Maneuvering Checks
• Perform Flight Management Computer-Attitude Hold Checks
• Perform Visionic Systems Checks
• Perform Hover Box Drift Checks
• Perform Initial Takeoff Checks
• Perform Engine Torque Factor Check
• Perform Cruise Flight Checks
• Perform Autorotation Revolutions Per Minute Check
• Perform Attitude Hold Check
• Perform Maneuvering-Flight Checks
• Perform Stabilator System Check
• Determine Turbine Gas Temperature Setting-Contingency Power
• Perform Communication and Navigation Equipment Checks
• Perform Sight-Sensor Checks
• Perform Weapon Systems Checks
• Perform Special-Detailed Procedures
• Perform Engine Shutdown Checks
• Perform Vh Check

Maintenance Evaluator (ME): Instructor/Trainer Tasks

• Operate a Flight Simulator
• Instruct Academic Subjects
• Evaluate Aircrew Academic Knowledge
• Instruct Aircrew Member Tasks
• Evaluate Aircrew Tasks
• Administer Aircrew Member Evaluation

Instructor Pilot (IP): Instructor/Trainer Tasks

• Operate a Flight Simulator
• Instruct Academic Subjects
• Evaluate Aircrew Academic Knowledge
• Instruct Aircrew Member Tasks
• Evaluate Aircrew Tasks
• Administer Aircrew Member Evaluation

Instrument Flight Examiner (IE): Instructor/Trainer Tasks

• Operate a Flight Simulator
• Instruct Academic Subjects
• Evaluate Aircrew Academic Knowledge
• Instruct Aircrew Member Tasks
• Evaluate Aircrew Tasks
• Administer Aircrew Member Evaluation

Unit Trainer (UT): Instructor/Trainer Tasks

• Operate a Flight Simulator
• Instruct Academic Subjects
• Instruct Aircrew Member Tasks### Crew Roles
• CPG (Copilot/Gunner) is the front seat crewmember.

Trainer/Evaluator Roles

• Acts as a functioning crewmember and performs as required during training and evaluations.
• Ensures safe landing areas are available for engine failure training and that aircraft limits are not exceeded.
• Recovers the aircraft from simulated malfunction within procedure parameters to prevent negative habit transfer.

Procedures

• Explains the portions of a task that an individual or crew accomplishes.

Considerations

• Essential information to consider when performing tasks under various flight modes and environmental conditions.
• Includes day, night unaided, and night aided conditions while using NVD (Night Vision Devices).
• Evaluates risk associated with task performance under certain environmental conditions.

Common Night/NVG/NVS Considerations

• Wires and other hazards are more difficult to detect and must be accurately marked and plotted on paper maps and TSD.

Operating Limitations and Restrictions

• Flight envelope limits.
• Wind limitations.
• Power limits.
• Airspeed limits.
• Rotor limits.
• Engine limits.
• Pressure limits.
• Temperature limits.
• Weather/environmental limitations/restrictions.
• MPD performance page/performance chart interpretation.
• Other limitations.

Aircraft and Systems

• Engines and related equipment.
• Flight control system/TRC.
• Flight instruments.
• Hydraulic system.
• Principal dimensions.
• Power train and mast mounted assembly.
• Auxiliary power unit.
• Environmental control system.
• Fuel system.
• Emergency equipment.
• Integrated pressurized air system (IPAS).

Regulations and Publications

• AR-95-1, Flight Regulations.
• DA PAM 738-751, Functional Users Manual for the Army Maintenance Management System-Aviation.
• TC 3-04.4, Fundamentals of Flight.
• TC 3-04.11, Commander’s Aviation Training and Standardization Program.
• TC 3-04.5, Instrument Flight for Army Aviators.
• DOD FLIP.
• Operator’s manual/CL.
• Local Regulations.
• Unit SOP.

Regulations and Publications Topics

• Inadvertent instrument meteorological condition (IIMC) procedures.
• Crew coordination.
• ATP, IATF/CTL requirements.
• DOD flight information and usage.
• Flight plan preparation and filing.
• Weight and balance requirements.
• Visual flight rules (VFR) minimums and procedures.
• Publications required in aircraft.

Aerodynamics and Maneuvering Flight

• Retreating blade stall.

Note: CUI stands for Confidentiality, Unclassified, and Integrity.

Helicopter Operations

• Establish and announce a forced landing or single engine flyaway plan when operating at an OGE hover
• Maintain ground track within 3 feet, constant rate of movement for existing conditions, and constant rate of turn during OGE hover

In-Flight Operations

• Maintain heading ±10 degrees, ground track alignment with minimum drift, and altitude ±100 feet
• Maintain airspeed ±10 knots and rate of climb or descent ±200 feet per minute (FPM)
• Maintain trim ±ball width and acknowledge low altitude warning audio

Crew Responsibilities

• Both crewmembers are responsible for performing crew coordination actions and announcing malfunctions or emergency conditions
• PC (Pilot Command) duties include briefing specific duties before entering the helicopter, maintaining airspace surveillance, and applying environmental considerations
• Copilot/Gunner (CPG) duties include assisting the PC and performing additional tasks as required

Hover Power Checks

• Initial hover power check should be completed at the beginning of the flight IAW Task 1038 (IGE power available and environmental conditions permitting)
• Hover power TQ (percent [%] TQ) baseline can be determined using PERF page (CUR, PLAN, or MAX mode) calculations
• Environmental and load considerations will be applied throughout the flight

Situational Awareness

• Situational awareness information will be provided to each crewmember through their individual HDUs
• PC will approve instances when it may be desired not to employ the HDU during the conduct of the mission or a specific flight maneuver

Altitude Definitions

• Minimum Safe Altitude (MSA) is defined as the minimum safe height above the surface or obstacles to which the helicopter can descend in a masked condition
• Minimum Maneuvering Altitude (MMA) is defined as the altitude above the mask or barriers at which the helicopter may safely hover### AH-64 MTL

Aviator (PI): Base Task Training

• Participate in a Crew Mission Briefing
• Plan a Visual Flight Rules (VFR) Flight
• Plan an Instrument Flight Rules (IFR) Flight
• Prepare a Performance Planning Card (PPC)
• Verify Aircraft Weight and Balance
• Operate Mission Planning System
• Perform Preflight Inspection
• Perform Before-Starting Engine through Before-Leaving Helicopter Checks
• Initiate Hot and High Dual Engine Training Mode
• Maintain Airspace Surveillance
• Perform Radio Communications Procedures
• Perform Ground Taxi Operations
• Perform Hovering Flight
• Perform a Visual Meteorological Conditions (VMC) Takeoff
• Navigate by Pilotage and Dead Reckoning
• Perform Fuel Management Procedures
• Perform a VMC Approach
• Perform Slope Operations
• Perform a Roll-On Landing
• Respond to Emergencies
• Perform Single-Engine Landing
• Respond to Engine Failure
• Respond to Dual Engine Failure
• Perform Stability and Command Augmentation System-Off/Backup Control System-On Flight
• Respond to Engine Overspeed-Underspeed Condition
• Perform Rolling Takeoff
• Perform Tactical Situation Display Operations
• Perform Basic Maneuvering Flight
• Perform Integrated Helmet and Display Sight System Video Adjustments and Boresight
• Perform Digital Communications Procedures
• Negotiate Wire Obstacles
• Operate Video Recorder
• Perform Instrument Takeoff (ITO)
• Perform Radio Navigation
• Perform Holding Procedures
• Perform Non-Precision Approach
• Perform Precision Approach
• Perform Unusual Attitude Recovery
• Respond to Inadvertent Instrument Meteorological Conditions (IIMC)
• Perform Refueling-Rearming Operations
• Perform Diving Flight
• Employ Aviator's Night Vision Imaging System
• React to Aviator's Night Vision Imaging System Failure
• Participate in a Crew-Level After Action Review
• Perform Night Vision System Operational Checks
• Perform Combat Maneuvering Flight
• Perform Target Handover
• Operate Infrared Laser Pointing Devices
• Perform Aerial Observation
• Perform Evasive Maneuvers
• Perform Actions on Contact

Tactical Training

• Perform Tactical Flight Mission Planning
• Operate Aircraft Survivability Equipment (ASE)
• Perform Target Store Procedures
• Perform Target Acquisition Designation Sight Sensor Operations
• Perform Fire Control Radar Operations
• Perform Electronic Countermeasures-Electronic Counter-Countermeasures Procedures
• Transmit Tactical Reports (Digital/Voice)
• Perform Terrain Flight Navigation
• Perform Masking and Unmasking
• Perform Firing Position Operations
• Perform Weapons Initialization Procedures
• Perform Firing Techniques
• Engage Target with Semi-Active Laser Hellfire Missile
• Engage Target with Radar Frequency Hellfire Missile
• Engage Target with Rockets
• Engage Target with Area Weapon System
• Perform Target Handover

Maintenance Test Pilot (MP): Maintenance Training

• Perform Prior to Maintenance Test Flight Checks
• Perform Maintenance Operational Check-Maintenance Test Flight
• Perform Interior Checks
• Perform Before-Starting Auxiliary Power Unit Checks
• Perform Starting Auxiliary Power Unit Checks
• Perform After-Starting Auxiliary Power Unit Checks
• Perform Starting Engine Checks
• Perform Engine Run-Up and Systems Checks
• Perform Before Taxi Checks
• Perform Taxi Checks
• Perform Baseline and Normal Engine Health Indicator Test
• Perform Before Hover Checks
• Perform Hover Checks
• Perform Hover Maneuvering Checks
• Perform Flight Management Computer-Attitude Hold Checks
• Perform Visionic Systems Checks
• Perform Hover Box Drift Checks
• Perform Initial Takeoff Checks
• Perform Engine Torque Factor Check
• Perform Cruise Flight Checks
• Perform Autorotation Revolutions Per Minute Check
• Perform Attitude Hold Check
• Perform Maneuvering-Flight Checks
• Perform Stabilator System Check
• Determine Turbine Gas Temperature Setting-Contingency Power
• Perform Communication and Navigation Equipment Checks
• Perform Sight-Sensor Checks
• Perform Weapon Systems Checks
• Perform Special-Detailed Procedures
• Perform Engine Shutdown Checks
• Perform Vh Check

Maintenance Evaluator (ME): Instructor/Trainer Tasks

• Operate a Flight Simulator
• Instruct Academic Subjects
• Evaluate Aircrew Academic Knowledge
• Instruct Aircrew Member Tasks
• Evaluate Aircrew Tasks
• Administer Aircrew Member Evaluation

Instructor Pilot (IP): Instructor/Trainer Tasks

• Operate a Flight Simulator
• Instruct Academic Subjects
• Evaluate Aircrew Academic Knowledge
• Instruct Aircrew Member Tasks
• Evaluate Aircrew Tasks
• Administer Aircrew Member Evaluation

Instrument Flight Examiner (IE): Instructor/Trainer Tasks

• Operate a Flight Simulator
• Instruct Academic Subjects
• Evaluate Aircrew Academic Knowledge
• Instruct Aircrew Member Tasks
• Evaluate Aircrew Tasks
• Administer Aircrew Member Evaluation

Unit Trainer (UT): Instructor/Trainer Tasks

• Operate a Flight Simulator
• Instruct Academic Subjects
• Instruct Aircrew Member Tasks### Crew Roles
• CPG (Copilot/Gunner) is the front seat crewmember.

Trainer/Evaluator Roles

• Acts as a functioning crewmember and performs as required during training and evaluations.
• Ensures safe landing areas are available for engine failure training and that aircraft limits are not exceeded.
• Recovers the aircraft from simulated malfunction within procedure parameters to prevent negative habit transfer.

Procedures

• Explains the portions of a task that an individual or crew accomplishes.

Considerations

• Essential information to consider when performing tasks under various flight modes and environmental conditions.
• Includes day, night unaided, and night aided conditions while using NVD (Night Vision Devices).
• Evaluates risk associated with task performance under certain environmental conditions.

Common Night/NVG/NVS Considerations

• Wires and other hazards are more difficult to detect and must be accurately marked and plotted on paper maps and TSD.

Operating Limitations and Restrictions

• Flight envelope limits.
• Wind limitations.
• Power limits.
• Airspeed limits.
• Rotor limits.
• Engine limits.
• Pressure limits.
• Temperature limits.
• Weather/environmental limitations/restrictions.
• MPD performance page/performance chart interpretation.
• Other limitations.

Aircraft and Systems

• Engines and related equipment.
• Flight control system/TRC.
• Flight instruments.
• Hydraulic system.
• Principal dimensions.
• Power train and mast mounted assembly.
• Auxiliary power unit.
• Environmental control system.
• Fuel system.
• Emergency equipment.
• Integrated pressurized air system (IPAS).

Regulations and Publications

• AR-95-1, Flight Regulations.
• DA PAM 738-751, Functional Users Manual for the Army Maintenance Management System-Aviation.
• TC 3-04.4, Fundamentals of Flight.
• TC 3-04.11, Commander’s Aviation Training and Standardization Program.
• TC 3-04.5, Instrument Flight for Army Aviators.
• DOD FLIP.
• Operator’s manual/CL.
• Local Regulations.
• Unit SOP.

Regulations and Publications Topics

• Inadvertent instrument meteorological condition (IIMC) procedures.
• Crew coordination.
• ATP, IATF/CTL requirements.
• DOD flight information and usage.
• Flight plan preparation and filing.
• Weight and balance requirements.
• Visual flight rules (VFR) minimums and procedures.
• Publications required in aircraft.

Aerodynamics and Maneuvering Flight

• Retreating blade stall.

Note: CUI stands for Confidentiality, Unclassified, and Integrity.

Learn about the primary and utility hydraulic systems, their similarities and differences, and how they provide hydraulic pressure to flight control systems.