What does specific fuel consumption (SFC) measure?

What does specific fuel consumption (SFC) measure?

• A. The maximum fuel capacity of the aircraft.
• B. The fuel efficiency of an engine, typically the amount of fuel required to generate unit thrust for a period of time.
• C. The total time an engine can run at idle.
• D. The rate of fuel consumption during takeoff only.

Answer: (B)

Specific fuel consumption measures how efficiently an engine uses fuel to produce thrust, by expressing the fuel flow required per unit of thrust over time. In practice, it’s the amount of fuel needed to generate a certain thrust for a period (often shown as pounds of fuel per hour per pound of thrust, or their metric equivalents). Lower SFC means the engine uses less fuel to produce the same thrust, indicating better efficiency. It’s not about how much fuel the aircraft can carry, how long the engine can idle, or fuel use only during takeoff; it’s a general efficiency metric that compares fuel consumption relative to thrust.

Specific fuel consumption measures how efficiently an engine uses fuel to produce thrust, by expressing the fuel flow required per unit of thrust over time. In practice, it’s the amount of fuel needed to generate a certain thrust for a period (often shown as pounds of fuel per hour per pound of thrust, or their metric equivalents). Lower SFC means the engine uses less fuel to produce the same thrust, indicating better efficiency. It’s not about how much fuel the aircraft can carry, how long the engine can idle, or fuel use only during takeoff; it’s a general efficiency metric that compares fuel consumption relative to thrust.