Which inputs does the FMS use to calculate performance data during takeoff and climb?

• A. Aircraft weight, center of gravity, runway and altitude, wind, temperature, OAT, air data from ADC, and planned route
• B. Only fuel quantity and outside air temperature
• C. Engine type and manufacturer year
• D. Cabin pressurization level and seat configuration

Answer: (D)

The inputs that the FMS uses for performance data during takeoff and climb are those that directly influence the aircraft’s lift, thrust, drag, and climb capability. Total weight and center of gravity determine how much thrust and lift you need and where the aircraft balances, while runway length and field elevation set the starting conditions for takeoff. Environmental conditions matter too: wind affects ground speed and performance, and temperature (and outside air temperature) changes air density, which in turn impacts engine thrust and aerodynamic performance. The air data from the air data computer provides accurate pressure and temperature information needed for speed and altitude calculations. Planning the route helps the FMS project the climb profile and required speeds.

Cabin pressurization level and seat configuration don’t affect the takeoff/initial climb performance calculations in the FMS. They are cabin and interior configuration factors and don’t change the physics of lift, thrust, or air density used in these performance calculations.