Sec. 25.1419 - Ice protection.
If certification with ice protection
provisions is desired, the airplane must be able to safely operate in the
continuous maximum and intermittent maximum icing conditions of appendix
C. To establish that the airplane can operate within the continuous
maximum and intermittent maximum conditions of appendix C:
(a) An analysis must be performed to
establish that the ice protection for the various components of the
airplane is adequate, taking into account the various airplane operational
(b) To verify the ice protection
analysis, to check for icing anomalies, and to demonstrate that the ice
protection system and its components are effective, the airplane or its
components must be flight tested in the various operational
configurations, in measured natural atmospheric icing conditions and, as
found necessary, by one or more of the following means:
(1) Laboratory dry air or simulated
icing tests, or a combination of both, of the components or models of the
(2) Flight dry air tests of the ice
protection system as a whole, or of its individual components.
(3) Flight tests of the airplane or its
components in measured simulated icing conditions.
(c) Caution information, such as an
amber caution light or equivalent, must be provided to alert the
flightcrew when the anti-ice or de-ice system is not functioning normally.
(d) For turbine engine powered
airplanes, the ice protection provisions of this section are considered to
be applicable primarily to the airframe. For the powerplant installation,
certain additional provisions of subpart E of this part may be found
[Amdt. 25-72, 55 FR 29785, July 20, 1990]