CFR

23.1505—Airspeed limitations.

(a) The never-exceed speed V NE must be established so that it is—

(1) Not less than 0.9 times the minimum value of V D allowed under § 23.335; and

(2) Not more than the lesser of—

(i) 0.9 V D established under § 23.335; or

(ii) 0.9 times the maximum speed shown under § 23.251.

(b) The maximum structural cruising speed V NO must be established so that it is—

(1) Not less than the minimum value of V C allowed under § 23.335; and

(2) Not more than the lesser of—

(i) V C established under § 23.335; or

(ii) 0.89 V NE established under paragraph (a) of this section.

(c) Paragraphs (a) and (b) of this section do not apply to turbine airplanes or to airplanes for which a design diving speed V D /M D is established under § 23.335(b)(4). For those airplanes, a maximum operating limit speed (V MO /M MO -airspeed or Mach number, whichever is critical at a particular altitude) must be established as a speed that may not be deliberately exceeded in any regime of flight (climb, cruise, or descent) unless a higher speed is authorized for flight test or pilot training operations. V MO /M MO must be established so that it is not greater than the design cruising speed V C /M C and so that it is sufficiently below V D /M D and the maximum speed shown under § 23.251 to make it highly improbable that the latter speeds will be inadvertently exceeded in operations. The speed margin between V MO /M MO and V D /M D or the maximum speed shown under § 23.251 may not be less than the speed margin established between V C /M C and V D /M D under § 23.335(b), or the speed margin found necessary in the flight test conducted under § 23.253.

Code of Federal Regulations

[Doc. No. 4080, 29 FR 17955, Dec. 18, 1964, as amended by Amdt. 23-7, 34 FR 13096, Aug. 13, 1969]

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