Definition
A measure of the fuel efficiency of a jet or turbofan engine, expressed as the weight of fuel burned per hour for each pound of thrust produced. It is typically stated in pounds of fuel per hour per pound of thrust (lb/hr/lb).
Plain English
How much fuel a jet engine burns each hour to produce one pound of pushing force. The lower the number, the more efficient the engine.
Context Anchor
Seen in turbine and jet engine performance discussions, especially when comparing engine efficiency or estimating fuel use.
Derivation
‘Specific’ here means ‘per unit of output.’ So ‘thrust specific fuel consumption’ literally means ‘fuel consumption measured against the thrust produced.’ This parallels ‘brake specific fuel consumption’ used for piston engines, which is measured against horsepower instead of thrust.
Why Pilots Care
Lower values mean the engine uses less fuel for the same thrust, directly improving range, endurance, and operating costs.
Analogy
It is loosely like fuel mileage for an engine, but instead of asking how far the aircraft goes on a gallon, it asks how much fuel the engine needs to make a given amount of push.
Intuition Check
Do not read “specific” as meaning “exact” or “particular” here. In this term, it means fuel burn measured per unit of thrust.
Example Sentence 1
The new turbofan offered a lower thrust specific fuel consumption than the older engine, giving the aircraft a longer range on the same fuel load.
Example Sentence 2
During flight planning the crew selected the power setting that balanced thrust needs against the engine's thrust specific fuel consumption.