POF 2

The term angle of attack is defined as:

• the angle between the relative airflow and the horizontal axis

• the angle between the wing chord line and the relative airflow

• the angle that determines the magnitude of the lift force

• the angle between the wing and tailplane incidence

An aircraft carries out a given journey, on two separate days. On both days, the pilot flies at an indicated airspeed of 120 knots. On the first day, the air density is greater than on the subsequent day. How will the forces of Lift and Drag acting on the aircraft compare on the two days?

• On the first day both Lift and Drag will be less than on the subsequent day

• On the first day the Lift will be greater and Drag will be less than on the subsequent day

• On the first day the Lift will be less and Drag will be greater than on the subsequent day

• The forces of Lift and Drag acting on the aircraft will remain unchanged

As airspeed increases, induced drag:

• Increases

• Decreases

• is dependent on the weight of the aircraft

• remains unchanged

As airspeed increases induced drag______, parasite drag and total drag __

• increases increases increases

• increases decreases increases then decreases

• decreases decreases decreases

• decreases increases decreases then increases

By changing the Angle of Attack of a wing, the pilot can control the aeroplane's:

• lift and airspeed, but not drag

• lift, gross weight and drag

• lift, airspeed and drag

• lift and drag, but not airspeed

That portion of the aircraft's total drag created by the production of lift is called;

• arasite drag, which is greatly affected by changes in airspeed

• induced drag, which is not affected by changes in airspeed

• induced drag, which is greatly affected by changes in airspeed

• parasite drag, which is inversely proportional to the square of the airspeed

If the Indicated Air Speed of an aircraft is increased from 50 kt to 100 kt, parasite drag will be:

• four times greater

• six times greater

• two times greater

• one quarter as much

Resistance, or skin friction, due to the viscosity of the air as it passes along the surface of a wing, is a type of:

• induced drag

• form drag

• parasite drag

• interference drag

How do Lift and Parasite Drag vary with airspeed?

• lift and Parasite Drag both decrease as the square of the airspeed

• lift decreases as the square of the airspeed while Parasite Drag increases as the square of the airspeed

• lift increases as the square of the airspeed while Parasite Drag decreases as the square of the airspeed

• lift and Parasite Drag both increase as the square of the airspeed

Parasite drag varies with:

• the square of the airspeed

• CL max

• the airspeed

• the weight of the aircraft, only