What is the correct expression for the Factored Landing Distance?

• A. The Dry FLD equals 1.92 x ALD.
• B. The Wet FLD equals 1.92 x ALD.
• C. The Factor LD equals 1.0 x ALD.
• D. FLD equals 1.67 x ALD.

Answer: (D)

Factored Landing Distance represents a conservative planning distance derived from the Available Landing Distance to account for adverse conditions and braking variability. The standard way this is expressed is FLD = 1.67 × ALD, giving a buffer beyond the actual runway length available for landing and stopping.

That 1.67 multiplier provides a fixed safety margin to accommodate factors like degraded braking on contaminated surfaces, wind effects, runway slope, and temperature impacts. Other forms like distinguishing dry or wet conditions or using different multipliers aren’t aligned with the common planning method, since the purpose is to apply a single, conservative factor to ALD.