1-g Stall Speed as the Basis for Compliance With Part 25 of the Federal Aviation Regulations

This action amends the airworthiness standards for transport category airplanes to redefine the reference stall speed for transport category airplanes as a speed not less than the 1-g stall speed instead of the minimum speed obtained in a stalling maneuver. The FAA is taking this action to provide for a consistent, repeatable reference stall speed; ensure consistent and dependable maneuvering margins; provide for adjusted multiplying factors to maintain approximately the current requirements in areas where use of the minimum speed in the stalling maneuver has proven adequate; and harmonize the applicable regulations with those currently adopted in Change 15 to the European Joint Aviation Requirements-25 (JAR-25). These changes will provide a higher level of safety for those cases in which the current methods result in artificially low operating speeds.