SIFT Aero.

Question 1

A helicopter is:

Answer 1

A type of rotorcraft

Question 2

Helicopter turbine engines produce ___ thrust per pound than piston engines:

Answer 2

More

Question 3

The main forces acting on a helicopter are:

Answer 3

Lift, Weight, Thrust, Drag

Question 4

Helicopters typically have between ___ and ___ main rotor blades:

Answer 4

2, 6

Question 5

Depending on the type of helicopter, main rotor systems can include:

Answer 5

Stab- bar, upper and lower swash plates, counterweights, pitch horns, teeter or coning hinges, blade grips, pitch and scissor links, and control rods.

Question 6

The function of the fly bar is:

Answer 6

To decrease crosswind thrust on the blades and enhance flight stability by keeping the bar stable as the rotor spins

Question 7

Many helicopters have a horizontal stabilizer located:

Answer 7

On the tail boom

Question 8

The purpose of the tail rotor is:

Answer 8

To produce an anti-torque force acting perpendicular to the helicopters longitudinal axis

Question 9

Wheels on ___ types of helicopters are ___.:

Answer 9

Some, retractable

Question 10

A pilot controls a helicopter using:

Answer 10

Pedals, Collective, Throttle, Cyclic

Question 11

From a physics perspective, the ___ force is deemed to act through a helicopter’s ___.:

Answer 11

Total weight, Center of gravity

Question 12

When a pilot banks a helicopter, causing it to turn, ___.:

Answer 12

The machines weight increases

Question 13

In the case of helicopters, lift is produced by ___ moving through the air at a speed sufficient to create ___.:

Answer 13

Airfoils, A pressure differential

Question 14

Thrust acts ___ to the aircraft’s ___.:

Answer 14

Parallel, Longitudinal axis

Question 15

Profile drag consists of:

Answer 15

Drag that is created by the frictional resistance of spinning airfoils.

Question 16

Vortices produced by spinning rotor blades create:

Answer 16

Induced drag.

Question 17

When plotted on a graph, L/DMAX is the point where the helicopters:

Answer 17

Total lift-to-drag ratio is the greatest

Question 18

A helicopter’s potential energy is affected by:

Answer 18

The aircraft’s height above the ground.

Question 19

Which factors affect the lift produced by spinning rotor blades:

Answer 19

Airfoils coefficient of lift, Air density, Blade area

Question 20

What happens when a helicopters main rotor blades spin rapidly?

Answer 20

The upper and lower sides of each blade experience a difference in pressure.

Question 21

Newton’s third law of motion applies to helicopters because:

Answer 21

The spinning main rotor makes the aircraft try to spin the opposite direction.

Question 22

When the pilot pushes the cyclic forward:

Answer 22

The main rotor disk tilts forward.

Question 23

Multi-engine helicopters have:

Answer 23

A throttle for each engine

Question 24

When the pilot wants the helicopters nose to move left or right, they:

Answer 24

Push on the corresponding pedal

Question 25

For helicopter with a main rotor disk that spins counter-clockwise, the ___ airflow speed happens when each blade reaches the ___ position:

Answer 25

Maximum, Three o’clock (right)

Question 26

On the advancing rotor blade, lift ___ and the blade ___.:

Answer 26

Increases, Moves upward

Question 27

The angle between the ___ of a rotor blade and its direction of motion relative to the ___ is the angle of attack, which is ___ angle.:

Answer 27

Chord line, Air, An aerodynamic

Question 28

The angle of incidence is between the ___ line of each blade and the rotor system’s ___.:

Answer 28

Chord, Plane of rotation

Question 29

When a helicopter engine ___, a clutch mechanism called a ___.:

Answer 29

Fails; freewheeling unit automatically disconnects the engine from the main rotor, allowing it to spin freely.

Question 30

During an autorotation in forward flight, the rotor disk takes in ___ air and the driven, driving, and stall regions of each blade move ___ along its length span, but only on the ___ side of the disk:

Answer 30

Upward flowing, Outboard, Retreating

Question 31

Where there is too much lift, the main rotor blades will:

Answer 31

Flap

Question 32

Centrifugal force ___ spinning helicopter main rotor blades ___.:

Answer 32

Pulls, Outward

Question 33

If left uncorrected, greater lift produced by the advancing side of the rotor disk compared to the lift created by the disk’s retreating side could make the helicopter:

Answer 33

Uncontrollable

Question 34

The driven region is ___ the blade tips and normally ___ percent of the radius:

Answer 34

Nearest, 30

Question 35

The ___ region is normally between a blades ___ and ___ regions.:

Answer 35

Driving, Stall, Driven

Question 36

Because of gyroscopic precession, if a wind gust applies a downward force on the left side of a helicopters main rotor disk as it spins clockwise (as viewed from above), the movement response occurs at the ___ o’clock position:

Answer 36

12

Question 37

Helicopters experience effective translational lift while transitioning to forward flight at approximately ___ to ___ knots:

Answer 37

16, 24

Question 38

Maximum ground effect occurs during a hover up to a height equal to ___ percent of the rotors diameter:

Answer 38

100

Question 39

A pilot can worsen a helicopter’s pendular action by:

Answer 39

Over-controlling the aircraft.

Question 40

The phenomenon of a helicopter sinking into its own downwash is called:

Answer 40

Settling with power