View all text of Subjgrp 81 [§ 25.251 - § 25.255]
§ 25.253 - High-speed characteristics.
(a) Speed increase and recovery characteristics. The following speed increase and recovery characteristics must be met:
(1) Operating conditions and characteristics likely to cause inadvertent speed increases (including upsets in pitch and roll) must be simulated with the airplane trimmed at any likely cruise speed up to V
(2) Allowing for pilot reaction time after effective inherent or artificial speed warning occurs, it must be shown that the airplane can be recovered to a normal attitude and its speed reduced to V
(i) Exceptional piloting strength or skill;
(ii) Exceeding V
(iii) Buffeting that would impair the pilot's ability to read the instruments or control the airplane for recovery.
(3) With the airplane trimmed at any speed up to V
(4) Adequate roll capability to assure a prompt recovery from a lateral upset condition must be available at any speed up to V
(5) With the airplane trimmed at V
(i) An excessive positive load factor when the pilot does not take action to counteract the effects of extension;
(ii) Buffeting that would impair the pilot's ability to read the instruments or control the airplane for recovery; or
(iii) A nose down pitching moment, unless it is small.
(b) Maximum speed for stability characteristics, V
(c) Maximum speed for stability characteristics in icing conditions. The maximum speed for stability characteristics with the most critical of the ice accretions defined in Appendices C and O of this part, as applicable, in accordance with § 25.21(g), at which the requirements of §§ 25.143(g), 25.147(f), 25.175(b)(1), 25.177(a) through (c), and 25.181 must be met, is the lower of:
(1) 300 knots CAS;
(2) V
(3) A speed at which it is demonstrated that the airframe will be free of ice accretion due to the effects of increased dynamic pressure.