Definition
The thrust produced by a turbojet or turbofan engine per unit of airflow passing through it, typically expressed as pounds of thrust per pound of air per second. It is a measure of how much thrust an engine extracts from each unit of air it processes.
Plain English
How much pushing force an engine gets from each pound of air flowing through it every second. A higher number means the engine works each pound of air harder.
Context Anchor
Seen in turbine engine theory and performance comparisons, especially when comparing different jet engine designs.
Derivation
In engineering, 'specific' means 'per unit of something' — usually per unit of mass or flow. So 'specific thrust' simply means 'thrust per unit of airflow,' the same way 'specific fuel consumption' means 'fuel used per unit of thrust.'
Why Pilots Care
It guides engine selection and design trade-offs that affect aircraft acceleration, size, and range.
Grounding Statement
Picture a jet engine taking in air and turning each bit of that moving air into a certain amount of forward push.
Intuition Check
Specific does not mean “exact” or “particular” here. It means “for each unit of airflow.”
Example Sentence 1
Turbojet engines have a higher specific thrust than high-bypass turbofans, which is why they were favored for early supersonic designs.
Example Sentence 2
Designers raised specific thrust by increasing turbine inlet temperature while keeping mass flow constant.