Aircraft Performance Limits and Design Requirements (14 CFR 61.316)
What Defines a Light-Sport Aircraft
The LSA definition is the backbone of this domain. An airplane LSA must have a maximum gross takeoff weight of 1,320 pounds (1,430 pounds if equipped for water operations), a maximum stall speed of 45 knots calibrated airspeed in the landing configuration, a maximum speed in level flight of 120 knots calibrated airspeed, a single reciprocating engine, a fixed or ground-adjustable propeller, a fixed or retractable landing gear (except for gliders and seaplanes), and no more than two seats. It must also have a maximum seating capacity of two persons including the pilot.
Performance and Operating Limits
Because the stall speed is capped, LSA handling is generally benign, but the low wing loading means significant sensitivity to gusts and density altitude. Candidates should understand how weight, temperature, and altitude combine to degrade climb performance. V speeds must be respected: Vne, Vno, and Vfe differ by type, and the practical test expects you to know the published values for your aircraft.
Traps
Examiners frequently test the difference between calibrated and indicated airspeed for the 45-knot and 120-knot limits, and the 1,430-pound seaplane allowance. Another trap: a ground-adjustable propeller is permitted, but an in-flight controllable propeller is not. Retractable gear is allowed on some LSA, but not on gliders or seaplanes under the definition.
Worked Example
If a candidate is asked whether a 1,400-pound amphibious airplane with a 44-knot stall speed qualifies, the answer is yes, because the seaplane weight allowance raises the limit to 1,430 pounds and the stall speed is below 45 knots.