Specific Excess Power

Specific excess power (Ps) is a metric that quantifies the rate of change of energy per unit weight, representing how quickly an aircraft can trade speed for altitude (or vice versa) at a given flight condition. Developed by John Boyd in the 1970s as part of energy maneuverability theory, Ps is essential for assessing aircraft performance during combat maneuvering, climb, and acceleration. Specific excess power is widely used in military aircraft design, flight envelope analysis, and tactical air combat assessment.