Tail Rotor

Question 1

How many blades

Answer 1

2

Question 2

Describe the Delta hinge

Answer 2

• Stainless steel yoke attached to output shaft via a splined trunnion
• Trunnion provides flapping axis through elastomeric bearings
• Compensates for dissymmetry of lift

Question 3

How is the yoke attached to the TR blade root

Answer 3

attached by 2 bolts on each side, for a total of four bolts.

Question 4

Describe the Static stop and yield indicators

Answer 4

• On output shaft, inboard of yoke
• Provides visual to determine if yoke has been stressed beyond limits
• Would appear as deformations due to excessive yoke contact

Question 5

Describe the Tail rotor and how aerodynamics are accomplished

Answer 5

2 blades, semi-rigid, teetering rotor system

• delta hinge compensates for dissymmetry of lift. The stainless steel yoke is attached to output shaft via a splined trunnion that provides for feathering as it flaps through elastomeric bearings
• Static stop and yield indicators provide visual indication of yoke is stressed beyond limits
• 2 pitch change bearings per blade with pedal creep weights to minimize control forces
• Span wise balance via washers
• Chord wise balance via weights and washers

Question 6

Describe the blade

Answer 6

2 asymmetrical composite blades

• Fiberglass/epoxy skin and spar
• Nomex honeycomb core
• Nickel plated stainless steel leading edge abrasion strip
• Coated with conductive pain to protect against lightnign strikes and conductivity
• ~2497 RPM
• 2.53:1 Reducing ratio
• 6.4 inch chord
• 65 inch diameter
• 0 degree blade twist

Question 7

Diameter

Answer 7

65 inches

Question 8

Chord

Answer 8

6.4 inches constant

Question 9

Blade Twist

Answer 9

0 degree

Question 10

RPM

Answer 10

~ 2497 RPM @ 100% Nr/Np

Question 11

Ratio

Answer 11

2.53:1 Reducing Ratio

Question 12

Describe the gear box

Answer 12

Magnesium housing mounted by 4 studs and 2 alignment pins

• 0.33 quart capacity
• 1 chip detector
• 90 degree direction change via 2 spiral bevel gears
• 2.53:1 reducing ratio, from 6,317 to ~2497RPM