§3.82 Definition of stalling speeds.

(a) Vso denotes the true indicated stalling speed, if obtainable, or the minimum steady flight speed at which the airplane is controllable, in miles per hour, with: (1) Engines idling, throttles closed (or not more than sufficient power for zero thrust), (2) Propellers in position normally used for take-off, (3) Landing gear extended, (4) Wing flaps in the landing position, (5) Cowl flaps closed, (6) Center of gravity in the most unfavorable position within the allowable landing range, (7) The weight of the airplane equal to the weight in connection with which Vso is being used as a factor to determine a required performance. (b) Vs1 denotes the true indicated stalling speed, if obtainable, otherwise the calculated value in miles per hour, with: (1) Engines idling, throttles closed (or not more than sufficient power for zero thrust), ght in connection with which Vs1 is being Climb (2) Propellers in position normally used for take-off, the airplane in all other respects (flaps, landing gear, etc.) in the particular condition existing in the particular test in connection with which Vs1 is being used, (3) The weight of the airplane equal to the weight in connection with which Vs1 is being used as a factor to determine a required performance. (c) These speeds shall be determined by flight tests using the procedure outlined in §3.120.