Rotor Systems

Question 1

What kind of main rotor system is on the MH-60S?

Answer 1

Four-bladed, fully articulated main rotor system

Question 2

What are the four subsystems of the main rotor system?

Answer 2

• Main rotor blades
• Hub
• Flight controls
• Bifilar vibration absorber

Question 3

What does the main rotor head do?

Answer 3

Transmits flight control inputs to the four main rotor blades

Question 4

What do the swashplates do?

Answer 4

Transmits flight control inputs to the main rotor blades through the control rods

Question 5

What do droop stops and flap restraints do?

Answer 5

Prevent extremely high or low blade flapping at low Nr

Question 6

When do the anti-flapping restraints pull out?

Answer 6

At 35% Nr or greater

Question 7

When do the droop stops typically pull out during run up?

Answer 7

At ~70% Nr

Question 8

When do droops typically seat during engine shutdown?

Answer 8

At ~50% Nr

Question 9

What is the makeup of each main rotor blade?

Answer 9

Each blade has a pressurized hollow spar,
honeycomb core, an outer skin, abrasion strips, electrothermal deicing mats, and a removable swept-back blade tip fairing

Question 10

How are the blade tips built?

Answer 10

They are built with a 20° swept tip

Question 11

What does the 20° swept tip on the main rotor blade do?

Answer 11

Provides for sound attenuation and increased rotor blade efficiency

Question 12

What is the spar of the main rotor blade pressurized with?

Answer 12

Nitrogen

Question 13

What is the purpose of the tail rotor blade system?

Answer 13

To provide antitorque reaction and direction control

Question 14

What lifting force does the tail rotor provide?

Answer 14

2.5% of the total lifting force

Question 15

What feature maintains positive pitch on the tail rotor system with the loss of both tail rotor control cables?

Answer 15

The spring-tension feature

Question 16

What does the tail rotor quadrant do?

Answer 16

Transmits tail rotor cable movements into the tail rotor servo