54H60-117 Propeller Flashcards
Which subassembly carries high centrifugal loads created by the prop blades?
Barrel
Which subassembly transmits engine torque to the prop blades?
Barrel
Which component delivers actual blade angle from the blade to the control assembly?
Beta feedback shaft
Which pitchlock component mechanically holds the stationary and rotating pitchlock ratchets apart during reversing and unfeathering operations?
Pitchlock control cam
What component is installed on the blade before the blade butt is formed during manufacture?
Beveled thrust washer
Which dome assembly part allows the rotating cam to turn while the stationary cam remains in a fixed position?
Ball bearings
Which dome assembly component limits cam travel and prevents the propeller from exceeding feather and reverse blade angles?
Stop ring
What function is a task of the low pitch stop assembly?
Prevent the prop from going into the beta range when the throttle is in the alpha range
Which components purpose is to provide electrical circuits between the brush block assembly and the deicing elements of the blade assemblies?
Deicer contact ring holder
During normal propeller operation, the output of of which pumps is used?
Main pressure and main scavenge
Which pumps are use during propeller static operation?
Auxiliary pressure and auxiliary scavenge
Which cam schedules a desired blade angle in the beta range?
Beta set
Which valve connects the main, standby, and auxiliary pressure pumps’ output to the increase pitch lines during negative torque conditions?
Feather valve
Which valve assists the feather solenoid valve with hydraulic positioning of the propeller an the pilot valves?
Feather actuating
What switch, In the valve housing, is opened by a cam 81 to 85 degrees prop blade angle?
PCBS
The governor speeder spring tension positions the pilot valve to maintain what percent RPM in the beta range?
109% to 113%
If the main filter becomes clogged, what valve opens to assure continued flow?
Bypass
When the backup valve is opened, the hydraulic pressure routed to the pilot valve is used for which operation?
Reverse
Which pressure pump is used to feather or unfeather the prop during during static operation?
Auxiliary
Which type of valve opens to allow the output of the standby pump to combine with the output if the main pump?
Check
When the standby pump is not required, where is it routed?
Pressurized sump
What type of force used during the pitchlock prevents the blades from decreasing pitch?
Centrifugal twisting moment
The purpose of the pitchlock assembly is to prevent?
Engine overspeed due to loss of hydraulic pressure
What prevents engagement of the stationary and rotating ratchets when blade angles are below 25 degrees and above 55 degrees?
The pitchlock control cam
What will keep the rotating and stationary ratchets disengaged when the blade angles are between 25 degrees and 55 degrees?
Increase- or decrease pitch pressure
What forces the stop levers on the low pitch stop to move outward?
Moveable wedge
When pressure builds to between 240 and 280 psi, which valve is unseated and and allow stop lever to retract?
Servo
What is coordinated by the throttle in a controllable pitch range?
Propeller blade pitch and engine fuel flow
Constant speed can only occur when the throttle is positioned from?
FLT IDLE to TAKE OFF
What is the beta range indication display on the coordinator?
0 to 34 degrees
During beta range, what moves the pilot valve?
Cams and mechanical linkage
In the beta range, which cam increases speeder spring tension?
Speed set
During beta range operation, which cams’ rotation moves the mechanical linkage to the center of the governor pilot valve?
Beta follow-up
During alpha range operation, which cam changes speeder spring tension so the governor pilot valve can maintain 100 percent engine speed?
Speed set
During an overspeed condition in the alpha range, the flyweights move the governor pilot valve to meter hydraulic fluid, which will?
Increase blade angle
Once an overspeed condition is corrected and the pilot valve is returned to the center position, what is the result?
System is back on-speed
During an underspeed condition, what moves the pilot valve?
Speeder spring
When feathering the prop, what acts on the mechanical linkage to actuate the feather actuating valve?
Manuel feather cam
During feathering operation, the feather valve is positioned to meter hydraulic fluid to the?
Forward end of the dome piston
Which valve is a backup in case the feather valve fails during feathering operation?
Feather solenoid
During feathering operation, which valve blocks off the standby pump output and causes hydraulic pressure to increase?
Feather actuating
During feather operation, what range on psi of fluid pressure opens the pressure cutout switch contacts?
600 to 800
Which component is the primary electrical ground for energizing the feather override holding coil?
Pressure cutout switch
When attempting to unfeather the prop on flight, where must the throttle be positoned?
Above FLT IDLE
Which two cams on the alpha shaft control the prop unfeathering operation?
Manual feather and beta set
What is the minimum psi required to release the feather latches and allow the piston to move forward?
200
After the NTS system actuator rod positions the mechanical linkage in the valve housing when a negative torque condition occurs, what component is shifted?
Feather actuating valve
Besides maintaining the optimum blade phase angle relationship between all propellers, synchrophasing also?
Keeps the propellers rotating at the same speed
What switches has spring-loaded guards to hold them in the NORMAL position?
Propeller governor control switches
What percent rpm in the alpha range are fuel governing check switches used to reset the propeller governor?
106%
On the speed bias motor, what results when the control winding voltage is different from the reference-winding voltage?
Speed bias motor rotates, and increases or decreases blade angle
The master synchrophaser board located in the synchrophaser unit contains a master channel and a slave channel used by what propellers?
No. 2 and No. 3
How much change in rpm does the compensating network in the synchrophaser unit allow the speed bias motor to correct?
2%
In mechanical governing mode, what causes the pilot valve to move and set the propeller speed?
Speeder spring or flyweights
Which propeller governing modes add more functionality to basic mechanical governing mode?
Normal and synchrophasing
For the prop to operate in normal governing mode, the propeller governor control switch must be in the NORMAL position and the throttle must be?
At or above FLT IDLE and the synchrophaser master switch in the OFF position
When an increase in rpm occurs during engine speed stabilization, how is an overspeed condition prevented?
Decrease speeder spring tension and position the pilot valve to increase blade angle
How many slave channels are contained on the master synchrophaser board in the synchrophaser unit?
One
If the slave prop blades are in the correct phase angle position during the synchrophasing governing mode, what is the resultant phase error voltage?
Zero
