Definition
A type of vertical navigation (VNAV) descent path that is computed and flown by the aircraft's flight management system (FMS) using aircraft performance data — including weight, speed, wind, and configuration — rather than being defined by fixed published altitude constraints alone. The FMS calculates the optimum descent profile to meet altitude and speed restrictions while accounting for the airplane's actual performance.
Plain English
A descent path the airplane's computer works out for itself based on how the aircraft is actually performing that day, instead of just following set altitudes printed on a chart.
Context Anchor
Seen in vertical navigation planning when the airplane’s navigation system predicts whether a climb or descent can meet planned altitude points along the route.
Derivation
"Performance" here refers to aircraft performance data (weight, speed, winds, drag) used to compute the path. "Path" is the vertical track the aircraft follows down. Together: a descent track shaped by how the airplane is actually performing, not by fixed numbers on a chart.
Why Pilots Care
It tells the pilot whether the planned descent will be flyable without speed or configuration problems.
Grounding Statement
Picture the VNAV system asking, “Given this airplane, this speed, this weight, and this wind, where can we actually be as we climb or descend?”
Intuition Check
A performance path is not about pilot skill or how well a flight is being graded. It means a calculated vertical path based on how the aircraft is expected to perform.
Example Sentence 1
The crew briefed that the arrival would be flown as a performance path, so the FMS would compute the top-of-descent based on current weight and forecast winds.
Example Sentence 2
Because the aircraft was heavy, the computed performance path required a shallower descent angle than the geometric path on the chart.