Category Archives: Principals of Flight

Principals of Flight

Which statement on dynamic longitudinal stability of a conventional aeroplane is correct?

A: Speed remains constant during one period of the phugoid.
B: Damping of the phugoid is normally very weak.
C: Period time of the phugoid is normally 5 s.
D: Damping of the short period oscillation is normally very weak.

 

 

 

 

 

 

 

 

Answer: B

If the RPM lever of a constant speed propeller is moved forward during a glide with idle power and whilst maintaining constant airspeed, the propeller pitch will:

A: increase and the rate of descent will increase.
B: increase and the rate of descent will decrease.
C: decrease and the rate of descent will increase.
D: decrease and the rate of descent will decrease.

 

 

 

 

 

 

 

 

Answer: C

An aeroplane has the following flap positions: 0(degrees), 15(degrees), 30(degrees), 45(degrees). Slats can also be selected. Generally speaking, which selection provides the highest positive contribution to the CLMAX?

A: The flaps from 30(degrees) to 45(degrees).
B: The slats from the retracted to the take-off position.
C: The flaps from 0(degrees) to 15(degrees).
D: The flaps from 15(degrees) to 30(degrees).

 

 

 

 

 

 

 

 

Answer: B

After the transition point between the laminar and turbulent boundary layer:

A: the mean speed increases and the friction drag decreases.
B: the boundary layer gets thinner and the speed increases.
C: the mean speed and friction drag increases.
D: the boundary layer gets thicker and the speed decreases.

 

 

 

 

 

 

 

 

Answer: C