Final answer:
The rule of thumb for calculating the maximum crosswind is unrelated to the headwind component. In projectile physics the time of flight for a projectile with a doubled horizontal velocity and unchanged vertical component remains the same.
Step-by-step explanation:
What Is the Rule of Thumb for Calculating Max Crosswind? The rule of thumb for calculating the maximum crosswind is not related to the headwind component at all, hence the correct answer is d) Unrelated to the headwind component. This is because the crosswind component is a measure of the wind's force perpendicular to the aircraft's direction of travel, whereas the headwind component is the measure of the wind's force against the direction of travel. Pilots use these calculations to decide whether it is safe to take-off or land, based on their specific aircraft's limitations.
The GRASP (Ground, Range, Altitude, Speed, Pilot) check is a concept in aviation, but in the context of this question which is more related to projectile physics the answer for the effect on a projectile's time of flight when the horizontal component of velocity is doubled and the vertical remains unchanged is: a. The time to reach the ground would remain the same since the vertical component is unchanged.