Forces Acting on an Aircraft Quiz

What happens when thrust is increased during level flight?

What must a pilot do if the aircraft starts to climb in level flight?

What happens to lift as angle of attack increases?

When is the coefficient of lift maximum?

Why is velocity important for the production of lift?

What is the force that opposes the forward force of thrust?

Which force acts perpendicular to the flight path through the centre of lift?

What opposes lift and acts vertically downward through the aircraft's center of gravity?

If an aircraft is in straight-and-level flight, what must remain equal to maintain a constant airspeed?

What happens if an aircraft's engine power is reduced during level flight?

How does an aircraft gain speed in straight-and-level flight?

Thrust and Flight Dynamics

Increasing thrust during level flight results in acceleration, unless opposing forces are adjusted.
A pilot must control the aircraft's ascent by adjusting pitch and managing the throttle to maintain level altitude.

Lift and Angle of Attack

Lift increases as the angle of attack rises, reaching a critical point where further increases result in stall.
The coefficient of lift reaches its maximum at a specific angle of attack, known as the critical angle.

Velocity and Lift Production

Velocity is crucial for lift production; higher speeds increase airflow over the wings, enhancing lift.

Opposing Forces

Drag, the force opposing thrust, acts against the aircraft's forward motion.
Weight opposes lift and acts downward through the aircraft's center of gravity.

Flight Equilibrium

To maintain a constant airspeed in straight-and-level flight, thrust must balance drag, ensuring no net acceleration.

Changes in Power and Speed

Reducing engine power during level flight leads to a decrease in airspeed unless the pilot compensates by adjusting altitude or attitude.
An aircraft gains speed in straight-and-level flight by increasing thrust or decreasing drag, facilitating acceleration.

Test your knowledge on the four forces acting on an aircraft in straight-and-level, unaccelerated flight: thrust, drag, lift, and weight. Understand the functions of each force and how they interact to keep an aircraft in equilibrium.