chapter 1 Helicopter Fundamentals

Because of === a force applied against a rotating body takes affect 90° later in the direction of === -

Gyroscopic procession

Rotation

The === was the first mass produced helicopter -

Sikorsky R-4

In helicopters, torque is applied in a === rather than a === plane -

Horizontal

Vertical

An air foil with a === surface produces more lift than air foil with a === surface -

Smooth

Rough

Most helicopter rotors use a === air foil -

Symmetrical

A relative wind striking the leading edge of the air foil directions to head on produces === therefore, this foil must have a === -

Zero lift

Angle of attack

Powered vertical flight was not possible until the basic concept of === was conceived and solved -

Lead-Lag

Rotation for the rotary wing on an autoGyro is provided by the === -

Windmill effect of airflow

The primary aft control on a helicopter is the === -

Tail rotor

The major function of the answer is to overcome ===, and provide the means of controlling the === -

Rotor torque

Direction of the nose of the aircraft

Which of these paved the way for powered rotary wing aircraft to fly successfully? -

Flapping hinge

The first licensed commercial helicopter was produced by -

bell

On a helicopter, which of these are supplied by the main rotor blades -

Both thrust and lift

Which of these airfoils does not work well for helicopter rotors because of a shift and the aerodynamic center of pressure -

Negative camber

Which of these is not a factor and how much left in air foil can develop -

Blade material

Which of these is the point at which burbling takes place? -

Critical angle of attack

Why are high altitude rescue operations with helicopters extremely difficult? -

Low density air reduces lift

What remains in one position at all angles of attack -

the center of pressure of a symmetrical airfoil

Which of these can a helicopter do that a fixed wing aircraft cannot -

Land with zero forward speed

Some older Bell helicopters had a blank assembly that rotated with the hub -

Stabilizer bar