Flight Theory & Principles Flashcards

What principle explains how lift is generated on a wing?

Answer: Bernoulli’s Principle

Bernoulli's Principle explains that as the speed of a fluid increases, its pressure decreases. An aircraft wing is shaped as an airfoil, causing air to flow faster over its curved upper surface than its flatter lower surface. This speed difference creates a pressure differential, with lower pressure above the wing and higher pressure below, generating the upward force of lift.

What are the four primary forces acting on an aircraft in flight?

Answer: Weight, drag, lift, and thrust

The four primary forces acting on an aircraft in flight are lift, weight, thrust, and drag. Lift is the upward force opposing weight, which is the downward force due to gravity. Thrust is the forward force generated by the engine, counteracting drag, which is the resistance caused by air opposing the aircraft's motion.

How does increasing angle of attack affect lift?

Answer: Increases lift until stall point

Increasing the angle of attack generally increases lift because it directs more air downwards, creating a greater pressure differential across the wing. However, this increase is only effective up to the critical angle of attack. Beyond this point, the airflow separates from the wing's upper surface, leading to a sudden and significant loss of lift known as a stall.

What is the role of ailerons during flight?

Answer: They manage roll control

Ailerons are movable control surfaces located on the trailing edge of each wing. They work differentially, meaning one aileron moves up while the other moves down. This creates an imbalance in lift between the wings, causing the aircraft to roll around its longitudinal axis, which is essential for turning.

What is drag in aviation?

Answer: Air resistance opposing motion

Drag is the aerodynamic force that opposes an aircraft's motion through the air. It is primarily caused by the friction between the aircraft's surface and the air, as well as pressure differences created by the aircraft's shape. This resistance must be overcome by thrust for the aircraft to maintain or increase speed.

What causes a stall in flight?

Answer: Exceeding critical angle of attack

A stall occurs when an aircraft's wing exceeds its critical angle of attack, regardless of airspeed. At this point, the smooth airflow over the upper surface of the wing separates, becoming turbulent and unable to generate sufficient lift. This sudden loss of lift causes the aircraft to lose altitude or descend rapidly.

Which surface controls pitch on an aircraft?

Answer: Elevators

Elevators are control surfaces located on the horizontal stabilizer at the tail of the aircraft. When moved, they alter the aerodynamic force on the tail, causing the nose of the aircraft to pitch up or down. This controls the aircraft's climb or descent rate.

What is the function of flaps during takeoff and landing?

Answer: Increase lift and drag

Flaps are deployed during takeoff and landing to increase both the lift and drag produced by the wing. By extending the wing's surface area and curvature, they allow the aircraft to generate more lift at lower airspeeds, which is crucial for shorter takeoffs and slower, safer landings. The increased drag also helps in decelerating the aircraft for landing.

What is yaw in aircraft movement?

Answer: Rotation along vertical axis

Yaw refers to the rotation of an aircraft around its vertical axis, causing the nose to move left or right. This movement is primarily controlled by the rudder, located on the vertical stabilizer. Yaw is essential for coordinated turns and maintaining directional control during flight.