07 - System: Rotorsystem

Question 1

Rotorsystem: How is Nr measured?

Answer 1

By a slotted wheel which rotates past a sensor

(Instruction Manual - Basic 1 - Main Systems, Chapter 4, Paragraph 4.2.3.2)

Question 2

Rotorsystem: What are the components of the main rotor head?

Answer 2

1. Star arm
2. Spherical thrust bearing
3. Upper and lower sleves
4. Frequency adapter
5. Self-lubricating oscillating bearing

(Instruction Manual - Basic 1 - Main Systems, Chapter 4, Paragraph 4.3.1.)

Question 3

Rotorsystem: What are the functions of the Starflex?

Answer 3

• Connects the rotorhead to the mast
• Absorbs centrifugal loads
• Absorbs flapping (25% of flapping forces)
• Rigid in drag

(Instruction Manual - Basic 1 - Main Systems, Chapter 4, Paragraph 4.3.)

Question 4

Rotorsystem: What are the functions of the spherical thrust bearing?

Answer 4

• Allows the blade to change pitch while attached to the starflex
• Transfers centrifugal loads to the starflex
• Absorbs flapping (75% of flapping forces)
• Distorsion of drag forces (25% of drag forces)

(Instruction Manual - Basic 1 - Main Systems, Chapter 4, Paragraph 4.3.2.)

Question 5

Rotorsystem: What are the functions of the frequency adapter?

Answer 5

• Absorbs drag (75% of drag forces)
  
  • Dampens drag
  • Adjust the natural frequency

(Instruction Manual - Basic 1 - Main Systems, Chapter 4, Paragraph 4.3.2.)

Question 6

Rotorsystem: What are the functions of the upper and lower sleeves?

Answer 6

• Connects the blade to the rotorhub (via spherical thrust bearing)
• Connect the pitch change lever

(Instruction Manual - Basic 1 - Main Systems, Chapter 4, Paragraph 4.3.2.)

Question 7

Rotorsystem: What does the “self-lubricating oscillating bearing” allow the starflex to do?

Answer 7

Move freely inside the frequency adapter, while still being stiff in drag

(Instruction Manual - Basic 1 - Main Systems, Chapter 4, Paragraph 4.3.2.)

Question 8

Rotorsystem: What are the components of the blade?

Answer 8

1. Stainless steel strip
2. Roving spar
3. Glas fiber spar pocket
4. Foam core
5. Glass cloth skin
6. Polyurethane strip
7. Roving trailing edge insert

(Instruction Manual - Basic 1 - Main Systems, Chapter 4, Paragraph 4.4.3.)

Question 9

Tail rotor: What does the “see-saw” assembly ensure?

Answer 9

It ensures flapping to compensate for dissymetry of lift between the advancing and retreating blade.

(Instruction Manual - Basic 1 - Main Systems, Chapter 6, Paragraph 6.2)

Question 10

Tail rotor: What is the purpose of the “chinese weights”?

Answer 10

To balance the zero pitch return moment of the blades and thus reduse pitch control loads. (neutralizes aerodynamic forces)

(Instruction Manual - Basic 1 - Main Systems, Chapter 6, Paragraph 6.3.4)

Question 11

Tail rotor: Characteristics

• Diameter
• Weight
• Twist
• Angle preset

Answer 11

• Diameter: 1,86 m
• Weight: 4,6 kg
• Twist: 0°
• Preset angle: 10°

(Instruction Manual - Basic 1 - Main Systems, Chapter 6, Paragraph 6.4)

Question 12

Tail rotor: Which factors determine the pitch setting of the tail rotor?

Answer 12

• Air stream (aerodynamic forces)
• Chinese weights (neutralizes aerodynamic forces)
• Laminated half bearing (preset 10°)
• Pedals

(no specific reference)