Definition
The total thrust produced by a turbine engine measured at the exhaust nozzle while the aircraft is stationary, with no allowance made for the momentum of incoming air. It represents the raw output of the engine before subtracting the drag effect of accelerating intake air to engine speed.
Plain English
The total push the engine produces when the aircraft is not moving, measured straight out of the back without subtracting anything for the air being pulled in at the front.
Context Anchor
Seen in turbine engine performance discussions, especially when comparing the engine’s total produced thrust with the thrust actually available to move the aircraft.
Derivation
Gross comes from the Old French gros, meaning 'large' or 'whole.' In accounting and measurement, gross means the total amount before any deductions are made — like gross income before tax. Here it carries the same idea: the whole thrust figure, before the inlet air's momentum is subtracted to give net thrust.
Why Pilots Care
Distinguishing gross thrust from net thrust shows how engine output changes with airspeed and helps explain why an engine can produce more force while the aircraft gains less speed.
Grounding Statement
Picture the engine making a forward push, then remember that part of that push is offset by the effect of pulling moving outside air into the engine.
Intuition Check
“Gross” does not mean rough, unpleasant, or oversized here. It means total before deductions.
Example Sentence 1
On the test stand, the engine produced its rated gross thrust because the aircraft was not moving and there was no momentum drag to subtract.
Example Sentence 2
Technicians record gross thrust values to confirm the engine meets its rated output before installation.