AM.II.L.K2

From the FAA library

• 14 CFR Part 121 — Operating Requirements: Domestic, Flag, and Supplemental OperationsOpen
  14 CFR § 121.321 Operations in icing.

  this section. (1) The airplane must be equipped with a certificated primary airframe ice detection system. (i) The airframe ice protection system must be activated automatically, or manually by the flightcrew, when the primary ice detection system indicates activation ... system is activated, any other procedures in the Airplane Flight Manual for operating in icing conditions must be initiated. (2) Visual cues of the first sign of ice formation anywhere on the airplane and a certificated advisory airframe ice detection…

• Pilot Guide: Flight in Icing Conditionsp. 29
  Chapter 3. ICING EFFECTS, PROTECTION, AND DETECTION › 3-15. ICE DETECTION › a. Electronic

  cockpit will remain on. (2) Pilots should consult their AFM or POH to determine if their ice detection system is an advisory or primary system. The difference between the systems is the redundancy of the system and testing required ... certification. The majority of airplanes have an advisory system, which means the pilot is responsible for detecting ice and ensuring ice protection systems are activated. This is true even for ice protection systems that are automatically activated when the ice…

• Pilot Guide: Flight in Icing Conditionsp. 29
  Chapter 3. ICING EFFECTS, PROTECTION, AND DETECTION › 3-15. ICE DETECTION › b. Visual

  majority of airplanes have an advisory system, which means the pilot is responsible for detecting ice and ensuring ice protection systems are activated. This is true even for ice protection systems that are automatically activated when the ice detection system ... detects ice. (3) Currently, there are no electronic detection systems that can reliably detect ice crystals, although new systems are under development. b. Visual. Strategically located or unprotected protuberances visible to the crew may also serve as ice indicators…