HYDS Flashcards
What systems( Actual other systems) do the three hydraulic pumps provide pressure to?
Flight control system, APU system, rescue hoist system
The hydraulic pumps are essential for various operational components in these systems.
What is the hydraulic pressure supplied by the hydraulic pumps / what’s actuators are the expectation to the rule?
-> Where are they located?
–> What’s there PSI?
Approximately 3,000 psi
The exception is the pitch and roll trim actuators in the pilot-assist servo assembly, which operate at 1,000 psi.
True or False: Each hydraulic system can operate independently of the others.
True
The systems are designed to be redundant and can function autonomously.
What does the Leak Detection/Isolation (LDI) system assist with?
Isolation of hydraulic leaks
This system plays a critical role in maintaining hydraulic integrity.
The HYD warning will illuminate when…
This indicates multiple compound malfunctions in the hydraulic systems.
What components make up the No. 1 hydraulic system?
- No. 1 hydraulic pump
- No. 1 transfer module
- First stage of the primary servos
- First stage of the tail rotor servo
The No. 1 hydraulic system is crucial for rotor operation.
What indicators are marked on the level-indicator window of the reservoir? AKA what are do the colors mean on the Hyd Pump
- Underserviced (red)
- Normal (green)
- Overserviced (blue)
These indicators help in monitoring hydraulic fluid levels.
What occurs when the automatic low-level sensing switch detects low fluid levels on the #1 side specifcally? ( Think Caution)
1 RSVR LOW caution appears
This alerts the operator to potential issues in the hydraulic system.
What does the No. 1 transfer module do?
Routes hydraulic fluid from the No. 1 hydraulic pump to servos
It ensures proper distribution of hydraulic fluid.
What happens if No. 1 hydraulic system pressure is lost / where does it go?
The transfer/shuttle valve routes backup pump hydraulic fluid
This maintains functionality of the servos.
What is the role of the pressure switch in the No. 1 transfer module?
Illuminates the #1 HYD PUMP caution and signals LDI
This is essential for monitoring system pressure.
What does the No. 2 hydraulic system supply hydraulic pressure to?
The second stage of the primary servos and the pilot-assist servo assembly
What are the main components of the No. 2 hydraulic system?
- No. 2 hydraulic pump
- No. 2 transfer module
- Second-stage primary servos
- Pilot-assist servo assembly
What happens when the fluid level is low in the No. 2 hydraulic pump? ( Think cautions)
2 RSVR LOW caution appears
What is the function of the No. 2 transfer module?
Routes hydraulic fluid from the No. 2 hydraulic pump to the second stage of the primary servos and the pilot-assist servo assembly
How can hydraulic pressure to the pitch and roll trim actuators be secured?
By depressing the TRIM pushbutton on the AFCS CONTROL panel
What hydraulic pressure is approximately secured to the pitch and roll trim actuators?
Approximately 1,000 psi
What hydraulic pressure is approximately secured to the boost servos and SAS actuators?
Approximately 3,000 psi
How is hydraulic pressure to the boost servos secured?
By depressing the SAS/BOOST pushbutton on the AFCS CONTROL panel
What is the function of the SERVO switches?
Secure hydraulic pressure to an improperly operating primary servo stage
There are two switches, one on each collective.
What happens when either 1ST OFF or 2ND OFF is selected?
The associated servo shutoff valve is energized closed and hydraulic pressure to the respective stage is secured.
What is the purpose of the electrical interlock?
Precludes the securing of hydraulic pressure to both first and second stages simultaneously.
The backup hydraulic system is what source to the rescue hoist system?
The only source of hydraulic pressure.
What occurs if the BACKUP PUMP PWR circuit breaker is out and the backup pump is needed?
The hydraulic system must be configured so that the backup pump will not activate upon resetting the circuit breaker.
True or False: Backup pump initiation with AFCS heading hold engaged may cause AFCS heading hold failure.
True
What is the backup hydraulic pump powered by?
An ac electric motor.
What happens when the automatic low-level sensing switch closes located in the backup system
The BACK UP RSVR LOW caution appears.
What does the backup pump do in the ON position with weight on wheels?
Recirculates hydraulic fluid and maintains pressure in the APU accumulator and rescue hoist systems.
What does the backup pump do in the AUTO position with weight off wheels?
Automatically maintains hydraulic pressure to the No. 1 and/or No. 2 hydraulic systems.
What happens when the APU accumulator pressure is low and the backup pump is activated?
The backup pump will run for at least 90 seconds regardless of BACKUP HYD PMP switch position.
What team member tells the backup pump its time to go to work if a loss of px or fluid is detected?
The LDI
List the conditions that activate the automatic backup pump
- Loss of No. 1 hydraulic pump pressure
- Loss of No. 2 hydraulic pump pressure
- Loss of No. 1 hydraulic reservoir fluid
- Loss of pressure to the first stage of tail rotor servo
What is the function of the Backup system in the hydraulic system?
Routes hydraulic fluid from the backup hydraulic pump to various components including the No. 1 and No. 2 transfer modules, second stage of the tail rotor servo, rescue hoist, and APU accumulator.
What is the role of the priority valve in the utility module?
the priority valve may secure hydraulic pressure to the rescue hoist due to low system pressure
What does the velocity fuse in the utility module do?
Secures fluid flow to the APU accumulator if flow rate exceeds a prescribed limit.
Delete
What triggers the BACKUP PUMP ON advisory?
A pressure switch in the utility module senses backup hydraulic pump output pressure and closes a circuit if pressure is above a prescribed value.
In the NORM position, which hydraulic system powers the first stage of the tail rotor servo?
The No. 1 hydraulic system.
What happens if I swithed the tail servo switch to backup?
The backup pump pressurizes the second stage of the tail rotor servo .
What would cause the Backup Pump to want to supply hyd fluid to the #2 Tail rotor servo? (2 Anwsers)
Automatically if the No. 1 hydraulic system malfunctions or manually if the TAIL SERVO switch is placed in the BKUP position.
What is indicated by a loss of hydraulic pressure in the first stage of the tail rotor servo? ( Think Caution)
1 TAIL RTR SERVO caution.
What does the #2 TAIL RTR SERVO ON advisory indicate?
The second stage Tail rotor servo is being pressuriezed
What components does the LDI system incorporate / where do those parts receive inputs from?
Two logic modules that receive inputs from automatic low-level sensing and pressure switches.
What does the LDI system do if the leak is in the No. 2 hydraulic system?
It assumes the leak is in the pilot-assist servo assembly and secures hydraulic pressure to that assembly.
What must the pilot do if the leak continues after initial isolation?
The pilot must secure the affected primary servo using the SERVO switch.
What criteria must exist to initiate the hydraulic leak test?
- AC power
- BACKUP HYD PMP switch in AUTO position
- All hydraulic reservoirs full
- Weight On Wheels
- Rotors engaged
What is indicated by a satisfactory hydraulic leak test?
The appearance of the following cautions/advisories:
* #1 RSVR LOW
* #2 RSVR LOW
* BACK UP RSVR LOW
* SAS
* BOOST SERVO OFF
* AFCS DEGRADED
* #1 TAIL RTR SERVO
* #2 TAIL RTR SERVO ON
* BACKUP PUMP ON
* MASTER CAUTION
What must be done to restore normal operation to the hydraulic leak detection system after a leak test?
The HYD LEAK TEST switch must be placed to RESET momentarily, then back to NORM.
Fill in the blank: The LDI system assumes that if a leak is detected in the No. 1 hydraulic system, the leak is in the _______.
first stage of the tail rotor servo.
What is the pressure of the system when it is deenergized?
1,000 psi
With WOW and the Backup PMP AUTO ( Move me home)
Maintains hyd px to the No.1 and/or No.2 hyd system
With WOW and the Backup PMP ON ( Delete)
With #1/2 operating normally, maintains px in the APU Accumaltor and resue hoist
When do the #1 & #2 pumps become pressurized?
When the rotors begin turning
What channel is not boosted?
Roll
