Aeronautical Engineering Mechanics Quiz

• The ratio of the aircraft's weight to its thrust

• The ratio of the lift force to the drag force

• The ratio of the drag force to the lift force

• The ratio of the aircraft's speed to its altitude

If an aircraft has a lift to drag ratio of 15, what does this mean?

• The lift is 15 times greater than the drag

• The drag is 15 times greater than the lift

• The lift and drag are equal

• The aircraft can glide for 15 minutes

Which of the following will increase the gliding distance of an unpowered aircraft?

• Increasing the drag

• Increasing the lift to drag ratio

• Decreasing the lift to drag ratio

• Increasing the aircraft's weight

The glide ratio of an aircraft is defined as:

• The ratio of vertical distance descended to horizontal distance travelled

• The ratio of horizontal distance travelled to vertical distance descended

• The ratio of lift to weight

• The ratio of thrust to drag

An aircraft with a lift to drag ratio of 20:1 descends 500 metres. How far will it travel horizontally (ignoring wind)?

• 10,000 metres

• 25,000 metres

• 20,000 metres

• 5,000 metres

Which of the following factors does NOT directly affect the lift to drag ratio?

• Wing shape (aerofoil design)

• Surface roughness

• Aircraft paint colour

• Angle of attack

If the lift to drag ratio of a glider increases, what happens to its maximum gliding distance (assuming all other factors remain constant)?

• It decreases

• It increases

• It remains the same

• It becomes zero

A glider with a lift to drag ratio of 30:1 starts at an altitude of 1,000 metres. What is the maximum horizontal distance it can glide (ignoring wind)?

• 3,000 metres

• 30,000 metres

• 300 metres

• 13,000 metres

Which of the following statements is TRUE regarding the lift to drag ratio?

• A higher lift to drag ratio means more efficient flight

• A lower lift to drag ratio means more efficient flight

• Lift to drag ratio has no effect on flight efficiency

• Lift to drag ratio only affects powered aircraft

If a glider descends 200 metres and travels 4,000 metres horizontally, what is its lift to drag ratio?

• 10

• 15

• 20

• 25