Free Bachelor of Aviation Theory of Flight Questions and Answers — Questions and Answers

Question 1: A wing's angle of attack is the angle that the chord creates with:

The aircraft body
The ground
The horizon
The relative airflow (Correct answer)

Correct answer: The relative airflow

The angle of attack is a critical aerodynamic parameter that defines the angle between the wing's chord line and the direction of the oncoming air. The chord line is an imaginary straight line connecting the leading and trailing edges of the wing. This angle is crucial as it directly influences the amount of lift and drag generated by the wing.

Question 2: A wing's lift force acts at a 90-degree angle to:

The relative airflow (Correct answer)
Gravity
The chord of the wing
The centre of pressure

Correct answer: The relative airflow

Lift is defined as the component of the aerodynamic force that acts perpendicular to the direction of the relative airflow. This means that if the air is flowing horizontally, the lift force acts vertically upwards. This fundamental relationship ensures that lift is always oriented to oppose the aircraft's weight, enabling flight.

Question 3: The term for a wing's effectiveness is the

Lift/Angle of Attack ratio
Lift/Drag ratio (Correct answer)
Speed/Drag ratio
Speed/Lift ratio

Correct answer: Lift/Drag ratio

The Lift/Drag ratio (L/D ratio) is a primary indicator of a wing's or aircraft's aerodynamic efficiency. It quantifies how much lift is generated for every unit of drag produced. A higher L/D ratio signifies greater effectiveness, meaning the aircraft can fly further or stay airborne longer with less power, making it a direct measure of performance.

Question 4: At the point of the limitation in a fluid's path when it passes through a tube with a venturi, the fluid:

Heats up
Slows down
Creates a vacuum
Reduces in pressure (Correct answer)

Correct answer: Reduces in pressure

According to Bernoulli's Principle, when an incompressible fluid flows through a constricted section of a tube, like a venturi, its velocity increases. To maintain the conservation of energy, this increase in kinetic energy must be accompanied by a corresponding decrease in the fluid's static pressure. Therefore, at the narrowest point of the venturi, the fluid experiences a reduction in pressure.

Question 5: Increasing a wing's angle of attack until it sinks the least will:

Increase lift and speed
Increase lift and increase drag
Decrease lift and reduce drag
Increase lift and reduce drag (Correct answer)

Correct answer: Increase lift and reduce drag

Increasing a wing's angle of attack up to a certain point will increase lift. For minimum sink rate, an aircraft is typically flying at its best Lift/Drag ratio, which means it is generating the most lift for the least amount of drag. This optimal condition allows the aircraft to descend at the slowest possible rate, effectively increasing lift relative to drag.

Question 6: Speed and lift are proportionate. Which of the following would provide the same lift as a high angle of attack and low airspeed:

Low airspeed and more weight
Low airspeed and low angle of attack
High airspeed and high angle of attack
High airspeed and low angle of attack (Correct answer)

Correct answer: High airspeed and low angle of attack

Lift is proportional to the square of the airspeed and the angle of attack, among other factors. To maintain a constant amount of lift, if the airspeed is increased, the angle of attack must be decreased to compensate. Conversely, at low airspeeds, a higher angle of attack is required to generate sufficient lift to support the aircraft's weight.

Question 7: A wing's motion produces vortices. The name of such a vortex is

Standing vortex (Correct answer)
Starting vortex
Streaming vortex
Spinning vortex

Correct answer: Standing vortex

As a wing moves through the air, it creates a pressure differential, causing air to flow from the high-pressure area below the wing to the low-pressure area above it around the wingtips. This flow results in the formation of swirling air masses known as wingtip vortices. These persistent vortices, which trail behind the aircraft, are often referred to as standing vortices in the context of the overall flow field.

Question 8: A wing's aspect ratio is determined by:

Wing span divided by wing thickness
Wing area divided by wing span
Wing area divided by wing chord
Wing Span divided by wing chord (Correct answer)

Correct answer: Wing Span divided by wing chord

A wing's aspect ratio is a measure of its slenderness, calculated by dividing the wingspan by the average wing chord. Alternatively, it can be calculated as the square of the wingspan divided by the wing area. A high aspect ratio wing is long and narrow, generally offering greater aerodynamic efficiency, while a low aspect ratio wing is shorter and wider.

Question 9: A wing's center of pressure is located where:

The aircraft is balanced
The air pressure over the wing is giving most lift
The resultant forces of lift and drag act
The wing rotates when climbing or diving (Correct answer)

Correct answer: The wing rotates when climbing or diving

The center of pressure (CP) is the theoretical point on the wing where the resultant of all aerodynamic forces, including lift and drag, effectively acts. Its significance in aircraft dynamics is that it represents the point around which the wing tends to rotate due to changes in these aerodynamic forces. This rotation directly influences the aircraft's pitching moment, particularly during maneuvers like climbing or diving.

Question 10: The center of pressure shifts when a wing's angle of attack increases:

Everywhere
Nowhere
Forwards (Correct answer)
Backwards

Correct answer: Forwards

As a wing's angle of attack increases, the distribution of pressure over its surfaces changes, causing the center of pressure (CP) to shift. Generally, the CP moves forward towards the leading edge of the wing with an increasing angle of attack. This forward shift is a critical factor influencing the wing's pitching moment and longitudinal stability, especially as the wing approaches a stall.

Question 11: As soon as a wing stalls:

Lift decreases, drag decreases
Lift increases, drag increases
Lift decreases, drag increases (Correct answer)
Lift increases, drag decreases

Correct answer: Lift decreases, drag increases

A stall occurs when the wing's angle of attack becomes too great, leading to the separation of airflow over the upper surface and a loss of smooth lift-generating flow. This results in a dramatic decrease in lift, as the wing can no longer effectively generate upward force. Simultaneously, the turbulent, separated airflow significantly increases drag, making it difficult to maintain altitude or control.

Question 12: Which of the following best describes the ability of an airline to make a profit from its resources?

Fleet utilization (Correct answer)
Passenger satisfaction
On-time performance
Load factor

Correct answer: Fleet utilization

Fleet utilization measures how effectively an airline uses its aircraft assets, typically by the amount of time aircraft spend flying revenue-generating flights. High utilization means aircraft are productive for more hours each day, maximizing the return on significant capital investments and directly impacting an airline's operational efficiency and profitability. It ensures that expensive assets are actively contributing to revenue.

Question 13: The characteristic of induced drag is:

Decreasing with lift
Decreasing with speed (Correct answer)
Increasing with lift
Increasing with speed

Correct answer: Decreasing with speed

Induced drag is a type of drag that is inherently linked to the generation of lift, primarily caused by wingtip vortices. It is inversely proportional to airspeed, meaning that as an aircraft's speed increases, the induced drag decreases. This occurs because at higher speeds, less angle of attack is required to produce the same amount of lift, thereby reducing the strength of the wingtip vortices and the associated drag.

Question 14: You can carry the following types of ballast on your glider:

Sand or Water (Correct answer)
Lead
Brick or stone
Anything you like

Correct answer: Sand or Water

Gliders often use ballast to increase their weight, which allows them to fly faster and improve performance in certain conditions. Water ballast is commonly used because it can be easily loaded and, more importantly, dumped in flight to adjust the glider's weight as conditions change. Sand is another viable option, though less flexible for in-flight adjustments.

Question 15: Ballast is one type of additional weight that will have the following effects:

Speed and sink rate slowed, glide ratio unchanged
Speed and sink rate increased, glide ratio unchanged (Correct answer)
Speed and sink rate increased, glide ratio lengthened
Speed and sink rate increased, glide ratio shortened

Correct answer: Speed and sink rate increased, glide ratio unchanged

Adding ballast increases a glider's weight, requiring a higher airspeed to generate the necessary lift. This results in both an increased optimal flying speed and an increased minimum sink rate. However, the overall glide ratio, which is the ratio of horizontal distance traveled to vertical distance lost, remains largely unchanged because both speed and sink rate increase proportionally.

Question 16: You can lessen induced drag by:

Flying at minimum sink
Fewer (or thinner) lines or wires
High aspect ratio wings (Correct answer)
Shiny surfaces

Correct answer: High aspect ratio wings

Induced drag is primarily caused by wingtip vortices, which are stronger on wings with lower aspect ratios. By designing wings with a high aspect ratio (long and slender), the spanwise flow of air around the wingtips is reduced, thereby minimizing the strength of these vortices. This design feature effectively lessens induced drag, improving aerodynamic efficiency, as seen in gliders and long-range aircraft.

Free Bachelor of Aviation Theory of Flight Questions and Answers

A wing's angle of attack is the angle that the chord creates with: