12.102. Take-off Performance

12.102.4. Explain the difference between take-off distance required (TODR) and take-offdistance available (TODA). 

TODR is the distance you require from the start of the take off run to reach lift-off speed and then climb to 50 feet above the runway surface

12.102.2. Given typical performance data, demonstrate the ability to determine TODR

Calculate the pressure altitude
Enter the chart with the ambient temperature and move vertically downward to intercept the line representing the pressure altitude at the atltiude just calculated
Enter the next block horizontally and move across until the appropriate sloping line for the aircraft groos weight for takeoff is intercepted.
Move vertically up into the next block
Move vertically upward from the block below until the appropriate line representing the type of operation and the aerodrome surface is intercepted.
Move horizontally into the next block
With the 2 next blocks enter horizontally from the left and move in until the reference line is intercepted
From this point move up or down parallel with the sloping lines until the appropriate degree of up or downslope or head or tailwind is met
From here nmove horizontally to the right – read off TODR from the scale at the right

12.100. Performance Factors

12.100.18. Describe the hazards of windshear in the initial climb-out path, and on theapproach path. 

Climb out
With an increase in wind speed the aircraft experiences a steepening of the climb angle and a brief increase in rate of climb

Approach
If low level wind is calm or light and the wind higher up is stronger the angle of descent will steepen and rate of descent will increase

Both situations can result in premature contact with the ground

12.100.16(i) . frost or other contaminants/damage of lifting surfaces. 

Take off performance is strongly degraded by frost or other contaminants on the wing surface

12.100.16(h) . power available; 

12.100.16(g) . use/misuse of flaps; 

12.100.16(f) . headwind/tailwind component; 

A Headwind decreases TODR since it takes less time and therefore distance to reach flying speed
LDR is decreased

A Tailwind increases TODR as a onger time and ground distance are required to reach flying speed
LDR increases

12.100.16(e) . runway surface condition; 

Anything that increases the drag between the wheels and the runway surface will increase TODR
A slippery or wet runway will reduce braking action so the LDR increases