Rotor System

Question 1

the tail rotor rotates clockwise ( from left hand view) and generates “anti-torque” air flow to the right hand side. What is the result of this?

Answer 1

It forces the tail to the left naturally

Question 2

what are the rotor blades constructed from?

Answer 2

foam cored fiberglass and carbon fiber skin

Question 3

what is the purpose of the blade tips?

Answer 3

provide blade tip streamlining movement

Question 4

what is the purpose of the 6 trim tabs?

Answer 4

provide dynamic blade tracking and balancing

Question 5

what are the leading edges made from, and what is their purpose?

Answer 5

Stainless steel to provide erosion and abrasion protection

Question 6

how are the blades attached to the rotor system?

Answer 6

they are mounted to spherical thrust bearings and the elastomeric frequency adapters in between the mounting bars

Question 7

what is the purpose of the spherical thrust bearings?

Answer 7

Located at the center of the hub the spherical thrust bearings handle the centrifugal loads from the blades and also ‘twist’ to provide pitch rod change movement

Question 8

what is the purpose of the elastomeric frequency adapters in between the mounting bars?

Answer 8

mounted at the ends of the center hub, the frequency adapters absorb fore and aft loads (lead/lag) on the head

Question 9

what is the purpose of the droop rings?

Answer 9

provides support for the blades when the aircraft is static. Also supports the head during rotor slow down

Question 10

In high wind conditions, what prevents excessive blade conning (upward flap)?

Answer 10

Anti-conning stops. Located at each attachment bar
At 181-202 RPM the fly weight moves the contact arm out of the way and the springs retract the stops as the rotor speed decreases

Question 11

What controls tilt of the swashplate?

Answer 11

Cyclic inputs tilt of the swashplate

Question 12

The rotor head is —— in the flapping axis and ——- in the lead/lag axis?

Answer 12

flexible

ridged

Question 13

The assemblies that make up the rotor shaft assembly are?

Answer 13

the rotor shaft, swashplates, a conical housing, pitch change rods, and a blade droop restrainer ring.

Question 14

What is installed in the rotor blade to counteract natural flapping?

Answer 14

An integral brass weight is installed inside the leading edge to counteract natural flapping frequencies that result from the light composite blades.

Question 15

Why is there a grounding strap installed at the blade root?

Answer 15

To minimize radio and radar interference by equalizing static charges that may accumulate on the blade

Question 16

Where is the main rotor brake installed?

Answer 16

Mounted on the MGB oil cooler fan shaft. The brake is a mechanically operated friction disk and brake caliper device

Question 17

What does the Tail Rotor system consist of?

Answer 17

The tail rotor head consists of a rotor hub, central plate, pitch change spider, and a fairing.

Question 18

How are the tail rotor blades constructed? This process helps prevent “skin debonding.”

Answer 18

Each blade is constructed of composite materials by means of a Resin Transfer Molding (RTM) process,
which creates a single material construction and eliminates skin debonding

Question 19

what creates centrifugal retention on the tail rotor blades?

Answer 19

Centrifugal retention of each blade is made by a tension torsion bar made of 38 individual tension thin stainless steel layers.

Question 20

How are the tail rotor blades arranged and why?

Answer 20

The blades are arranged around the rotor hub in

an uneven pattern to reduce the noise signature.