Transmission & Rotor Flashcards
The Elastomeric bearings allow the blades to?
Flap, lead, lag and move about its axis for pitch changes
Anti-flapping restraints are out at ______.
Droops go in at ________ and out at __________
35% NR
50% NR
70% NR
The rotor blade tips are swept 20° to
Provide sound attenuation
And
Increased rotor blade efficiency
Tail rotor is
A crossbeam flexible spar canted 20° upward and provide 2.5% lift in a hover
The tail rotor indexing system:
Positions blades during pylon fold and
prevents the tail rotor from windmilling in winds up to 60kts when folded.
Whenever locking or unlocking the Gust Lock the switch must be
Held in position for at least 5 seconds
AVCS IBIT shall only be initiated when?
It corrects for the ___________ vibration
when Rotors are static to avoid damage to components
4 per revolution
What is primary function of transmission?
Secondary?
Take power from the engines, reduce the RPM, and transfer it to the main and tail rotors
Drive electric and hydraulic power
MGB has:
3° forward tilt
2 accessory mods
2 input mods
1 main module
The utility hydraulic system is mounted ____________.
On the right rear quadrant of main transmission
Diaphragm coupling allows
For slight misalignment of engine output shaft
Freewheeling unit allows
The transmission to disengage from the engine when NR exceeds NP (autorotation)
If loud whining noise is heard during rotor engagement you should
Shut down and trouble shoot. It could be a failure of the diaphragm coupler.
IGB does what?
Reduces shaft speed and changes angle of drive
Tail and IGB gearboxes are
Splash lubricated and provide gear reduction and change and angle of drive.
The main transmission oil system is
Wet sump
Also used by the AC generators
It is AIR cooled
MAIN TRANSMISSION OIL HOT caution comes on when?
117° C
MAIN TRANSMISSION PRESSURE LOW caution comes on when the
The psi is 14 or less
When is the chip detector burn off feature deactivated?
above 140° C
How many chip detectors are in the transmission?
Which is different?
5
Main module has a 30 second time delay. It also has a temperature sensor for the cockpit.
CHIP IBIT
Takes 2 minutes and interrupts 28 Vdc for 40 seconds (no WCAs or Master Caution lights)
TDI is on the ______.
Vertical NR sensor is on the _______.
Left
Right
Main Rotor RPM?
Tail?
258
1189
How is Rotor control provided?
Through the flight control hydraulic servos, which move control rods attached to the swashplate assembly.
How is the hydraulic fluid in the main rotor dampers pressurized?
Where is that hydraulic fluid stored?
It is Nitrogen-pressurized
a reservoir mounted inside the main rotor shaft.
Pitch control rods extend from the ___ to the ___ on each spindle
rotating swashplate
pitch change horns
Describe the main rotor blade.
Pressurized hollow spar, honeycomb core, outer skin, abrasion strips, electrothermal deicing mats, and a removable swept-back blade tip fairing.
How can you tell if the Main rotor blade is damaged?
The Blade Inspection Method (BIM) indicators show a black indication due to nitrogen escaping.
What happens if you lose both tail rotor control cables?
a spring-tension feature of the tail rotor control system will provide positive pitch on the tail rotor equivalent to left pedal for a midposition collective power setting
What happens if you lose one tail rotor control cable?
The tail quadrant will operated normally by controlling the remaining cable against spring tension.
You will get a TAIL ROTOR QUADRANT caution
Whenever locking or unlocking the gust lock, the GUST LOCK switch shall be held in the LKD or UNLK position for a minimum of __ to enable the actuator mechanism to complete its cycle.
5 seconds
How many sections does the tail drive shaft have?
What connects them?
six
Viscous damped bearings
What does the Input module do?
Provides the first gear reduction between the engine and the main module.
How does the engine output shaft provide drive from the engine to the input module?
the Diaphragm coupling
What does the Accessory module provide?
mounting and drive for the AC Gen and Hyd pump module.
Where is the Main Transmission low-oil pressure sensor located?
Left accessory module
Describe the route that Transmission oil takes
Oil is pumped from the sump to the Oil Filter (can be bypassed), then to the oil cooler, then through the various modules
Where are the pressure readings for the VIDS taken at?
MGB manifold inlet
When does the MAIN XMSN OIL HOT advisory appear?
When oil temp is greater than 105C and the caution has not been activated
Yellow tape - oil temp greater than or equal to 105 and less than or equal to 120 deg
Red tape - oil temp is greater than 120 deg
When does the MAIN XMSN PRESS LOW advisory appear?
When oil pressure is less than or equal to 30 psi, NR is greater than or equal to 25%, and the caution has not been activated
Yellow tape - oil px greater than or equal to 20 psi and less than or equal to 30 psi
Red tape - oil px less than or equal to 20 psi
When does the MAIN XMSN PRESS HI caution appear?
oil pressure greater than 130 psi
Tape will be red
When does the MAIN XMSN PRESS HI advisory appear?
When oil pressure is between 65-130 psi and the caution has not been activated
When does the INT XMSN OIL HOT or TAIL XMSN OIL HOT caution appear?
140C
What type of rotor system do we have?
Fully articulated
Dampers
1) restrain lead/lag during rotation
2) absorb rotor head starting loads
Purpose of droop stops and anti-flapping restraints
Prevent extremely high or low blade flapping at low Nr
Above __% Nr, centrifugal force holds anti-flapping restraints out in position to allow for
35%; flapping and coning of blades
Above __% Nr, centrifugal force holds droops out to allow for
70; increased vertical movement of blades
Elastomeric Bearing Purpose
Enable blades to flap, lead, lag and permit blade to move about its axis for pitch changes
Dampers are provided
Nitrogen pressurized hydraulic fluid
Gust Lock Primary Function
Lock rotor brake disc in indexed position and to prevent rotor brake disc from turning inadvertently should the rotor brake hyd px bleed off while the rotors are spread
When locking/unlocking gust lock, hold switch for minimum of __ seconds
5
Freewheeling units are located in
Input modules
PDI is located ___. A popped PDI indicates ___ but does not indicate ___.
On the oil filter (visible above sonobuoy launcher)
Mx is required after the last flight of the day
Lubrication system malfunction
Oil under pressure is supplied through ___ except for the ___
Internally cored oil lines
Px and return lines in and out of the oil cooler
Which chip detector also has temp sensor for vids?
Main chip
Main chip detector
- rests at lowest point of oil system
- contains embedded temp sensor
- incorporates 30 second time delay to further eliminate false warnings
