Rotor System, Contol System, XMSN Flashcards
What is the route of the mechanical flight controls (pilot input to main rotor)
Controls (cyclic, collective, pedals) ➡️ force-axis combined in overhead torque shaft (hyds bay) ➡️ pilot assist servos (PAS) ➡️ mixing unit (MU) ➡️ fwd, aft, lateral primary hydraulic servos ➡️ control rods ➡️ swashplate assembly ➡️ rotating swashplate ➡️ pitch control rods ➡️ pitch change horns
What is the mechanical route from the pilot control input to the tail rotor (mechanical flight control system)
Controls ➡️ force- axis combined in overhead torque shaft (hyds bay) ➡️ pilot assist servis (PAS) ➡️ mixing unit (MU) ➡️ tail rotor servo ➡️ tail rotor quadrant cables ➡️tail rotor
Main rotor
- 4 bladed
- CCW
- fully articulated
- 53’8” diameter
How are the rotor blades attached to the hub?
Via spindle assemblies and are retained via elastomeric bearings
What is on each spindle?
- blade lock-pin puller
- fold hinge
- blade fold actuator
- pitch lock actuator
- putch change horns (connected to pitch control rods)
What do blade lock-pin pullers look like and what do they do?
- “2 nips chained together”
- locks blades OUT so they don’t fold back
What does the fold hinge look like and what does it do?
- hinge on the “top face of the lollipop”
- blade rotates here when being folded
What absorbs vibrations on top of the rotor head?
What do you check on this during pre-flight?
Bipolar vibration absorber
Check that it is free to move and greased up
What does the swashplate assembly comprised of?
A stationary and rotating disc separated by a bearing. The outer disc (rotating swashplate) is what rotates around the rotar shaft,tilting about the teflon-coated uniball
What are main rotor dampers supplied with? What psi are they charged to?
Nitrogen-pressurised hydraulic fluid
1200 psi, you check charge and fluid level on pre-flight
Where are main rotor dampers located and what do they do?
They are mounted between each spindle assembly to absorb rotor hub sharing loads and restrain lead/lag
Tail rotor drive shaft is made up of?
- 6 sections, balistically hardened
- connected by Thomas couplings before the IGB
- connected together by 4 viscous damper bearings
When you increase collective, which direction does the nose yaw?
Right
When you decrease collective, which way does the nose yaw?
Left
What does the AVCS system do?
It reduces the duration of peak vibratory loads produced by the main rotor
(Meaning it reduces vibrations from main rotor)
Main rotoe causes what kind of vibrations?
4 per revolution