14 C.F.R. § 23.73 Reference landing approach speed.
Title 14 - Aeronautics and Space
(a) For normal, utility, and acrobatic category reciprocating engine-powered airplanes of 6,000 pounds or less maximum weight, the reference landing approach speed, VREF, must not be less than the greater of VMC, determined in §23.149(b) with the wing flaps in the most extended takeoff position, and 1.3 VSO. (b) For normal, utility, and acrobatic category reciprocating engine-powered airplanes of more than 6,000 pounds maximum weight, and turbine engine-powered airplanes in the normal, utility, and acrobatic category, the reference landing approach speed, VREF, must not be less than the greater of VMC, determined in §23.149(c), and 1.3 VSO. (c) For commuter category airplanes, the reference landing approach speed, VREF, must not be less than the greater of 1.05 VMC, determined in §23.149(c), and 1.3 VSO. [Doc. No. 27807, 61 FR 5187, Feb. 9, 1996]
Title 14: Aeronautics and Space
PART 23—AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES
Subpart B—Flight
Performance
§ 23.73 Reference landing approach speed.