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(b) The warning must be furnished either through the inherent aerodynamic qualities of the airplane or by a device that will give clearly distinguishable indications under expected conditions of flight. However, a visual stall warning device that requires the attention of the crew within the cockpit is not acceptable by itself. If a warning device is used, it must provide a warning in each of the airplane configurations prescribed in paragraph (a) of this section at the speed prescribed in paragraphs (c) and (d) of this section. Except for the stall warning prescribed in paragraph (h)(3)(ii) of this section, the stall warning for flight in icing conditions must be provided by the same means as the stall warning for flight in non-icing conditions.
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(e) * * *
(1) The most critical of the takeoff ice and final takeoff ice accretions defined in Appendices C and O of this part, as applicable, in accordance with Sec. 25.21(g), for each configuration used in the takeoff phase of flight;
(2) The most critical of the en route ice accretion(s) defined in Appendices C and O of this part, as applicable, in accordance with Sec. 25.21(g), for the en route configuration;
(3) The most critical of the holding ice accretion(s) defined in Appendices C and O of this part, as applicable, in accordance with Sec. 25.21(g), for the holding configuration(s);
(4) The most critical of the approach ice accretion(s) defined in Appendices C and O of this part, as applicable, in accordance with Sec. 25.21(g), for the approach configuration(s); and
(5) The most critical of the landing ice accretion(s) defined in Appendices C and O of this part, as applicable, in accordance with Sec. 25.21(g), for the landing and go-around configuration(s).
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(h) The following stall warning margin is required for flight in icing conditions before the ice protection system has been activated and is performing its intended function. Compliance must be shown using the most critical of the ice accretion(s) defined in Appendix C, part II, paragraph (e) of this part and Appendix O, part II, paragraph (d) of this part, as applicable, in accordance with Sec. 25.21(g). The stall warning margin in straight and turning flight must be sufficient to allow the pilot to prevent stalling without encountering any adverse flight characteristics when:
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Ground and Water Handling Characteristics