Definition
The actual climb performance an airplane is expected to achieve following an engine failure during takeoff, based on demonstrated flight test data without any safety margin applied. It represents the unfactored climb gradient the aircraft can produce under the conditions specified.
Plain English
The real climb a plane can manage with an engine out, based on what it actually did during testing — with nothing held back as a safety buffer.
Context Anchor
Seen in one-engine-inoperative takeoff planning, where the pilot or operator checks whether the airplane can clear obstacles after an engine failure during departure.
Derivation
‘Gross’ here comes from the older English sense meaning ‘whole’ or ‘before deductions’ — the same way ‘gross income’ means total earnings before tax. So the gross flight path is the total demonstrated performance before any safety deductions are taken out.
Why Pilots Care
It forms the starting point for verifying that the adjusted net flight path still provides safe obstacle clearance on engine-out departures.
Analogy
Gross flight path is like gross pay on a paycheck: it is the amount before deductions. The reduced planning path is like take-home pay: it is the smaller number you are allowed to count on.
Intuition Check
Gross does not mean sloppy, large, or heavy here. It means the full predicted climb path before subtracting the required safety margin.
Example Sentence 1
The gross flight path showed the aircraft could maintain a 2.4% climb gradient on one engine at the planned takeoff weight.
Example Sentence 2
Obstacle analysis begins by plotting the gross flight path to determine how much margin remains after adjustments.