Quote Originally Posted by Stryker View Post
This makes me think of another related topic... takeoff rotation speed... calculated based on weight and drag in the MDC.

Does this takeoff rotation speed factor in the "headwind-component" of the prevailing wind conditions?

headwind_component = cosine(wind_angle_off_runway_heading) x wind_speed

If the headwind_component is not factored in to the rotation speed calculation, then we should be subtracting the headwind_component from rotation speed to get the effective-rotation-speed for takeoff?

mdc_rotation_speed - headwind_component = effective_rotation_speed

So for example, if wind conditions are 25 knot wind at 10 deg off runway heading, then headwind_component is 24.6 knots of wind coming towards you on the runway.

Given that your rotation speed was calculated to be 130 knots, then
130 - 24.6 = 105.4 knots (effective-rotation-speed)


105 knots (effective-rotation-speed)
You're taking off referencing indicated airspeed so the best thing that can happen is that you use less runway. Don't subtract anything from KIAS!