The fuel fraction during the cruise phase of a flight, often referred to as “FFC” (Fuel for Cruise) or “Cruise Fuel Fraction,” represents the proportion of an aircraft’s total fuel consumption that is typically consumed during the cruise phase of a flight. This fraction is used to estimate the fuel required for maintaining level flight at cruising altitude.
The formula for calculating the Cruise Fuel Fraction () can be expressed as:
- “Fuel Burned during Cruise” is the amount of fuel consumed during the cruise phase of the flight, typically covering the distance between takeoff and landing (typically in kilograms or pounds).
- “Total Fuel Onboard” is the total amount of fuel carried by the aircraft at the start of the flight (typically in kilograms or pounds).