Rotor System Flashcards
What type of rotor system do we have?
Fully articulated
How are the main rotor blades attached?
Attach to hinged spindles and retained by elastomeric bearings
What is the purpose of elastomeric bearings?
Allow blade to lead, lag, and flap and permit blade to move about its axis for pitch change
What are the subsystems of the main rotor?
Blades
Hub
Flight Control
Bifilar Vibration Absorber
What do the blade dampers provide?
Restrain lead/lag and absorb rotor head starting loads
Where is the blade damper reservoir and how is it pressurized?
Reservoir is located in the main rotor shaft
Each damper is supplied with nitrogen pressurized HYD fluid
What does the low pressure plate provide?
Provides attachment to the swashplate
How are flight control inputs transmitted to the main rotor blades?
Inputs from flight controls routed to the swashplate then to the PCRs to the pitch change horns
What do droop stops and flap restraints provide?
Prevent extreme high/low blade flap at low Nr
When do flap restraints pull out?
~ 35% Nr
When do droop stops pull out?
~ 70% Nr
When do droop stops seat?
~ 50% Nr
What is the composition of the main rotor blades?
Pressurized hollow spar Honeycomb core Outer skin Abrasion strips - extend blade life De-Ice mats 20 degree swept back Blade Tips
What do the blade tips provide?
Sound attenuation and increased rotor efficiency
How are the blades pressurized?
Nitrogen and include Blade Inspection Method(BIM) to show damage (black) indication
How are the blades connected to the spindle?
Bolted flange
What does the Tail Rotor provide?
Anti-TRQ and directional control
How does the T/R provide control?
The flap and pitch changes come from the deflection of the flexible spar
What is the cant and total lift provided by the T/R?
20 degree upward cant and provide 2.5% total lift in a hover
What is happening in the T/R Quadrant when both cables are lost?
Spring tension feature provides a positive pitch on T/R equal to that of a mid-position collective setting
What does the T/R index system do?
Positions T/R blades during fold and prevents windmilling in winds up to 60 KIAS when folded
What does the T/R Quadrant provide?
Transmits all cable movements into the T/R servo
What happens if 1 T/R cable is broken?
Operates normally by controlling the other cable against spring tension and TAIL ROTOR QUADRANT caution illuminates from respective microswitch
How does the T/R Head work?
Consist of 2 plates. Inboard plate forms hub with the output shaft.
Hub plates absorb axial trust loads and bending moment and transmit TRQ to the blades.
Blade spars clamped together and the pitch change crossbeam is attached to the output shaft to provide pitch changes
