FAA Federal Aviation Regulations (FARS, 14 CFR)

(a) The established landing gear operating speed or speeds, VLO, may not exceed the speed at which it is safe both to extend and to retract the landing gear, as determined under §25.729 or by flight characteristics. If the extension speed is not the same as the retraction speed, the two speeds must be designated as VLO(EXT) and VLO(RET), respectively.

(b) The established landing gear extended speed VLE may not exceed the speed at which it is safe to fly with the landing gear secured in the fully extended position, and that determined under §25.729.

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as amended by Amdt. 25-38, 41 FR 55468, Dec. 20, 1976]