M12.3 VIBRATION TYPES AND VIBRATION REDUCTION METHODS

What is vibration?

• A) Linear motion

• B) Oscillatory motion

• C) Rotational motion

What can contribute to wear of mechanical, electronic, and airframe components due to vibration?

• A) Low exposure

• B) High exposure

• C) Medium exposure

What defines forcing frequencies on helicopters?

• A) Component rotation speeds and characteristics

• B) Fuel load

• C) Passenger comfort

Vibrations can accelerate wear and tear on various components of the helicopter, including the rotor blades, engine, transmission, and other critical parts, but they do not affect the stability and handling characteristics of the helicopter.

• True

• False

What is the primary source of vibratory forces on helicopters?

• A) Aerodynamic Forces and Unbalanced components

• B) Aerodynamic Forces and Structural configuration

• C) Unbalanced components and Structural Configuration

Vibrations in helicopters are usually classified into two main groups: low frequency and high frequency.

• True

• False

Which type of vibration is associated with an unbalanced condition in helicopters?

• A) High and medium frequency vibration only

• B) Medium frequency vibration only

• C) All types of frequency vibration

At what range do medium-frequency vibrations occur in helicopters?​ ​

• 2000 CPM and above
• 500 to 2000 CPM
• 0 to 500 CPM

What is the most common type of low-frequency vibration associated with the main rotor?​

• 1:1 vibration
• 2:1 vibration
• 3:1 vibration

High-frequency vibrations, perceived as a buzz, typically affect the main rotor, engine, and drive train systems.

• True

• False