How much tailwind component should be used for calculating flare/ground roll distances?

When calculating flare and ground roll distances, the tailwind component should be taken into consideration because it directly impacts the performance of the aircraft during landing. A tailwind increases the landing distance required for a safe stop, as it effectively reduces the deceleration force acting on the aircraft.

Using a tailwind component of 150% for these calculations allows for a more conservative and realistic approach to estimating distance requirements. This means that if the aircraft encounters a tailwind, it will need an increased amount of runway to complete the landing safely.

In practical terms, this percentage accounts for the various factors that can affect landing performance, such as aircraft weight, configuration, and environmental conditions. By utilizing this more generous tailwind component in calculations, pilots can better plan for landing distances and ensure they have adequate runway available for a safe approach and landing.