Flight Instructors Training Procedures _revised AIC_x

THRUST (T)
With the aid of a graph explain:
i. Power available curve (Pa).
ii. The effect of altitude on the power available curve.
iii. Propeller efficiency with airspeed.
DRAG (D)
i. Total drag – Total power required (Pr).
ii. Effect of altitude.
3. COMBINE THE THRUST/DRAG GRAPHS AND DISCUSS
i. MAXIMUM RATE OF CLIMB.
DEFINITION
Maximum height gained in a given time. Rate of climb is the vertical component of the flight
path velocity and depends upon the flight speed and the inclination of the flight path.
SPEED
That speed where the largest difference exists between Pa and Pr. This speed is higher than
for minimum drag due to propeller efficiency.
Formula: Rate of climb (FPM) = 33,000 x Pa-Pr
W
ii. EFFECT OF FLAP
For a given airspeed the section of optimum flap will give added lift with only a small increase
in drag. Therefore, it is possible to obtain the original amount of lift at a lower airspeed. The
rate of climb is a function of both angle and airspeed, and because of the lower airspeed with
flaps down, the rate of climb will always be reduced.
iii. BEST ANGLE OF CLIMB
DEFINITION
Maximum height gained in relation to minimum distance travelled – concerns obstacle
clearance.
SPEED
Usually lower than the best rate of climb speed, and for some aircraft the use of optimum flap
is recommended.
Formula: Sin of the climb angle = T - D
W
iv. ABSOLUTE CEILING
The gradual closing of the curves for Pa and Pr as altitude is gained will eventually mean that
there will be no excess Pa for climbing when the aircraft reaches its absolute altitude.
4. EFFECT OF WIND ON THE CLIMB
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