Flight controls & Hydraulics Flashcards
Which 5 lights will activate the back-up pump?
1 RSVR LOW
APU ACCUM LOW
What combines, sums and couples cyclic, collective and yaw inputs?
Mechanical Mixing Unit (MMU)
What hydraulic systems provides pressure to the 2nd stage tail RTR servo?
Backup HYD system
The backup hydraulic pump provides hydraulic pressure in case of failure of the #1 and/or #2 hydraulic pumps and for ______ ______ ______?
Ground operation checks
What are the positions on the BACKUP HYD PUMP switch?
ON, OFF, AUTO
Where is the TAIL SERVO switch located?
On the center console, misc. panel marked MISC SW
The collective and yaw boost servos are turned on and off by pressing the switch marked _______ on the AFCS panel.
BOOST
The pilot’s assist is normally pressurized by what HYD system?
No. 2 HYD system
SAS enhances dynamic stability and provides ______ ?
short-term rate damping in the pitch, roll, and yaw axis.
Inside the hydraulic pump, what shears to prevent any damage to the accessory modules in the evemt of mechanical failure?
Shear shaft
What are the four components on/within the transfer module?
Primary Shutoff valve
Transfer valve
Secondary shutoff valve
Pressure pump switch
How many indicator buttons are on each hydraulic system?
2
What are the primary servos (names), right to left while looking forward?
Forward
Aft
Lateral
(Fat Ass Lady)
What does the electrical interlocks prevent?
Both flight control servo stages from being turned off simultaneously.
Where is the Servo shutoff switch located?
Pilot or co-pilot collective head.
How is the #1 stage tail servo pressurized?
Normally: #1 hydraulic system
Emergency: Backup hydraulic system
What happens if both tail rotor control cables fail?
A centering spring on the servo will position tail rotor servo input linkage to provide 10,5 degrees of pitch.
The tail servo moves the ___________ that extends through the tail gear box to the pitch change links, to the tail rotor blade paddles.
pitch change shaft
1 RSVR LOW means hydraulic fluid level is below?
60% of full capacity.
What does the FLT PATH STAB advisory indicate?
The FPS is inop. in one or more axis.
What are the three hydraulic pressure supply systems?
1, #2 and Backup
What caution appears if the No. 1 hydraulic pump pressure is lost/below min.?
1 HYD PUMP
Which cautions/advisories cause hydraulic logic to automatically bring on the back-up hydraulic pump?
1 HYD PUMP
APU ACCUM LOW
When APU ACCUM LOW appears, hyd logic will bring on the backup hyd pump if the BACKUP HYD PUMP switch is in which position?
Any position (In flight, WOW will make OFF default to auto)
On the transfer module there are how many shutoff valves?
2
The pressure switch in the transfer module activates the #1 HYD PUMP caution when pressure drops below?
Minimum (2000 PSI)
What are the TAIL SERVO switch positions?
Normal
Backup
What are the malfunction types?
Leaks
Mechanical
Jams
In the #1 hydraulic system, how many steps are there to the hydraulic logic module Leak Detection/Isolation (LDI) sequence?
3
The indication that the leak was not in the tail rotor servo is when?
1 HYD PUMP light illuminates
The pilot assist module has a pressure reducer with a relief valve for the pitch trim actuator. What does it do?
Reduces normal system pressure from 3000 to 1000 PSI.
What does the transfer valve do?
Allows only one pump to provide pressure to the hydraulic system at a time.
What is the final light to illuminate for a primary servo jam?
1 or #2 PRI SERVO PRESS
The FLT PATH STAB (computer light) will remain on until?
The pilot does a Power On Reset.
What does the Backup Pump supply hydraulic pressure to?
2 TAIL RTR SERVO
Utility Module
APU accumulator
With two hyd systems inop, airspeed shall be limited to?
150 KIAS
140 IMC
Bank angles shall be limited to ________ when a PRI SERVO PRESS caution appears?
30 degrees
1 PRI SERVO PRESS indicates?
Lack of pressure or mechanical failure of one or more of the #1 Primary servos
If both tail rotor cables fail, a centering spring will position the tail rotor servo linkage to provide ______ degrees pitch
10 1/2
When performing hydraulic leak test (HYD LEAK TEST switch in TEST pos), what lights appear?
Master caution * 2
Cautions:
- # 1 Tail RTR SERVO
- BOOST SERVO OFF
- SAS OFF
- # 1 and #2 RSVR LOW
- BACK-UP RSVR LOW
Advisories:
- # 2 TAIL RTR SERVO ON
- BACK-UP PUMP ON
When performing the tail rotor servo transfer check and the TAIL SERVO switch is in BACKUP, the BACK-UP PUMP ON should appear within how many seconds?
3-5 seconds
What are the cockpit indications for a leak in the No. 1 HYD pump module?
- both MASTER CAUTION
- # 1 RSVR LOW
- # 1 HYD PUMP
- BACKUP PUMP ON
What happens if pilot action is not taken when a leak occurs at the 1st stage primary servo?
A loss of both the No. 1 and back-up hydraulic systems
A hardover failure of the collective boost servo will increase control forces as much as ______ pounds in the collective.
150 pounds
What indicates a TAIL ROTOR QUADRANT caution, with no change in handling characteristics?
One tail rotor cable broke
What are the functions of the MMU?
Collective to Pitch
Collective to Roll
Collective to Yaw
Yaw to Pitch
What system normally pressurizes the Pilot Assist Area?
2 HYD system
What controls are maintained when trim is engaged and the pitch, roll, and yaw trim systems are activated?
Cyclic (pitch and roll) and pedals at a desired position.
What is the minimum psi on the pressure gage for starting the APU?
2800 psi
Where are both of the logic modules located?
Cabin Ceiling mounted in the left and right relay panels
What components monitor reservoir fluid level switches on the hydraulic pump modules?
Hydraulic Logic Modules
The LDI system uses _______ and _________ for monitoring hydraulic pump fluid level, and pump pressure for primary and tail rotor servos, and pilot assist servos.
Pressure switches
Fluid level sensors
Step 1 in the Hydraulic Logic Module Operation Principle is handled by the __________.
Hydraulic Logic/LDI
Step 2 in the Hydraulic Logic Module Operation Principle is handled by the __________.
Transfer Valve
Step 3 in the Hydraulic Logic Module Operation Principle is handled by the __________.
Pilots Action
Pilot Assist module has shutoff valves. What are they?
Trim, SAS and Boost
(Three stuid boxes)
PRI SERVO PRESS, BOOST SERVO OFF Caution lights are usually associated with what type of malfunction?
Jams
What is the final light to illuminate for a primary servo jam?
PRI SERVO PRESS
The velocity fuse is located inside the__________.
Utility Module
The velocity fuse is routed to the ____________.
APU ACCUMULATOR
When the backup pump motor is powered by the main generators, it is depressurized to 700 psi for ____ sec.
1/2
When the BACK UP RSVR LOW Light appears, the pilot must take what action?
Move the SVO OFF switch to isolate the leak and save the backup hyd pump
Bank angles shall be limited to ______ degrees when a PRI SERVO PRESS caution appears
30 degrees
When performing the tail rotor servo transfer check and the TAIL SERVO switch in BACKUP, the BACKUP PUMP ON should appear within how many seconds?
3 to 5
A collective boost hardover will increase collective forces as much as _____ in the collective
150 lbs
A yaw boost hardover will increase yaw forces as much as ____ in the pedals.
250 lbs
A hardover failure of the pitch boost servo will increase the longitundal cyclic control forces approximately _____
20 lbs
What does the Utility module do?
directs hydraulic pressure from the backup pump to No.1/No. 2 transfer module, 2nd stage tail rotor servo, and the APU accumulator
What does the velocity fuse do?
shuts off hydraulic fluid to the accumulator if flow rate exceeds 1.5 gal/min
If one or both cables fail, what caution appears?
TAIL ROTOR QUADRANT
Trimmed flight is available at ________ KIAS.
25-145 Knots
What are the two cautions that are not pressure cautions?
TRIM FAIL and FLT PATH STAB
What advisory light indicates that correct timely action was taken?
BACKUP PUMP ON
