Aero Fact: Phugoid Mode Explained
A long-period oscillation trading kinetic and potential energy, typically lightly damped in general aviation aircraft.
By AircoreDynamics •
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1 min read
Definition: Long-period exchange between kinetic and potential energy; typically lightly damped.
Physics insight: One of the longitudinal modes derivable under small-angle assumptions.
Example: After a trim disturbance, altitude and airspeed slowly oscillate.
T ~ 20–60 s (typical), low ζ
Rules of thumb: Manage with gentle trim inputs; avoid overcontrol.
Common pitfalls: Risk of pilot-induced oscillation (PIO).
References: Stability and control notes