1: Helicopter Components, Systems, and Instruments

Question 1

Main Rotor Construction and MR Airfoil type/size

Answer 1

2 blades w/ honeycomb structure made of aluminum

Steel spar on the leading edge

Sizes on R22:
25’2” Diameter blades
7.2” Chord line inboard (chord line is the distance from leading to trailing edge)
7.7” Chord line outboard
-8* blade twist (helps with aerodynamic loading and with the weight of steel spar leading edge)

Semi-rigid rotor System (articulates)
Able to feather (change pitch)
Free to teter (both blades flap up as a single unit)
Rigid in plane (does not lead and lag)

Question 2

Tail Rotor Construction, Sizes, and Type

Answer 2

2 Blades made of all aluminum (no steel spar)

Same honeycomb construction as main rotor

On R22 tail rotor blades are asymmetrical (to be more efficient)

Purpose: Offsets torque created from main rotor

Sizes:
3’6” blade diameter
4” chord line
0* blade twist
Pre-cone angle 1*11’ (shorter than the main rotor, so they are pre-coned. Makes them efficient faster and produces less stress on blades)

Semi-rigid rotor System (articulates)
Able to feather (change pitch)
Free to teter (both blades flap up as a single unit)
Rigid in plane (does not lead and lag)

Delta 3 Hinge
Helps minimize blade flapping by reducing the pitch angle automatically

Question 3

Transmission

Answer 3

Direct Drive System (engine is connected to drive system)