Unit 5 - Aircraft Stability and Control

Stability in Aircraft Design

100

What are the two main types of stability in aircraft

• The two main types of stability are static stability and dynamic stability.

200

What do you call an aircrafts tendency to return to its original attitude when diplaced?

Positive Stability

300

Pitch stability refers to the movement of an aircraftʻs nose up and down around its...

lateral axis

400

What happens to an aircraft if the center of gravity moves aft?

The aircraft becomes progressively more difficult to control.

500

What is the importance of the wing design in aircraft stability?

Wing design is crucial for stability as it affects the aircraft's lift characteristics, stall behavior, and overall aerodynamic performance.

Rotorcrafts Lift and Stability

100

What is the primary source of lift for rotorcraft?

The primary source of lift for rotorcraft is the rotating blades (rotors).

200

How does rotor blade pitch affect lift in a helicopter?

Rotor blade pitch affects lift by changing the angle of attack; increasing pitch increases lift, while decreasing pitch reduces lift.

300

Describe how rotor speed influences stability in rotorcraft.

Rotor speed influences stability as higher rotor speeds can provide more lift and stability, while lower speeds can lead to less control.

400

Explain the concept of translational lift in rotorcraft.

Translational lift is the increase in lift experienced by rotorcraft when moving forward, due to the effect of increased airflow over the rotor blades.

500

What is the effect of wind on rotorcraft stability during flight?

Wind can affect rotorcraft stability by causing turbulence and altering the airflow around the rotors, which can lead to loss of control if not managed properly.

Primary and Secondary Flight Controls

100

What are the three primary flight controls of an aircraft?

The three primary flight controls are ailerons, elevators, and rudders.

200

What are the three axes of flight?

Longitudinal Axis

Lateral Axis

Vertical Axis

300

Name three ways a control input can be transmitted to a control surface

Hydraulic Pressure

Electronic Signals

Cable and Pulley

400

What role do flaps play in flight?

^{-They increase lift}

^{- They are retracted at cruising altitude}

^{- They are extended during landing}

500

Describe how lift changes in a turn.

^{An airplane requires a sideward force to change its lateral flight path. This force is generated by banking the airplane’s wings and forcing some of the upward lifting force to act sideways. The vertical component of lift in flight, which originally acted to balance the aircraft’s weight in straight-and-level flight, is broken into vertical and horizontal components in a turn. The horizontal component of lift acts in the intended direction of the turn and is responsible for “pulling” the airplane into the turn.}

Turns and Turning Flight

100

What is a bank angle in relation to turning flight?

A bank angle is the angle at which an aircraft is tilted during a turn, affecting the direction and rate of the turn.

200

Why does an airplane tend to descend in a turn?

The vertical component of lift decreases.

300

Propper rudder use can help you...

avoid a skidding turn.

400

An airplaneʻs rate of turn and itʻs airspeed are...

inversely proportional.

500

Describe what causes adverse yaw.

^{When entering a turn, the rising wing produces more lift than the descending wing. The
increased lift causes more drag, which pulls the nose of the aircraft in a direction opposite the turn.}

Load Limits in Aircraft Design

100

What would be the weight in pounds of a 180-pound person when subjected to a force of 3 g's?

540 pounds

200

What should a pilot do to minimize dangers from turbulence?

- Fly at maneuvering speed or slower

-avoid areas of rough conditions

300

During an approach to stall, an aircraft will stall at a higher speed when

the load factor is increased.

400

The amount of load that can be safely imposed on an airplane is dependent upon...

The speed of the airplane

500

How should a pilot operate an aircraft to avoid overstressing its structure?

_{Pilots should...}

_{- never operate an aircrarft outside of its acceptable weight and balance limitations}

_{- should slow to maneuvering or slower to help reduce stresses on airframe during moderate or greater turbulence.}

_{- should always stay clear of thunderstorms or other violent weather.}

_{- should only perform maneuvers for which the aircraft is rated.}

_{- should always operate within airspeed limitations}

_{-should use smooth control inputs especially when fully deflecting control surfaces}