CRD 2012-23

Turbine Engine Certification Specifications in Icing Conditions - Advisory Material

The aim of rulemaking task RMT.0179 is to upgrade CS-E 780 — ‘Turbine Engine Certification Specifications for Operation in Icing Conditions’. This upgrade was mainly triggered by the need to update the icing conditions used to evaluate turbine Engines installed on CS-25 aircraft. A new icing environment, including Supercooled Large Drop (SLD), mixed-phase and ice crystal icing conditions, is being concurrently introduced in CS-25; these changes were proposed under NPA 2011-03. The CS-E Specifications which were proposed under NPA 2011-04 require the Engine to function satisfactorily throughout the conditions of atmospheric icing, including freezing fog and falling and blowing snow, which are defined in the Air Intake System Ice Protection Specifications of the Certification Specifications applicable to the aircraft on which the Engine is to be installed.

This Comment-Response Document (CRD) contains the comments received on NPA 2012-23 (published on 04 December 2012) and the responses provided thereto by the Agency.

NPA 2012-23 proposed Acceptable Means of Compliance (AMC E 780) with the Ice Protection Specifications (CS-E 780) proposed under NPA 2011-03.

The proposed AMC has been updated based on the comments received. These updates consist of clarifications, corrections or addition of Guidance Material, while the substance and main principles of the AMC are maintained. A summary of the major comments, responses, and AMC changes is provided in Chapter 2 of this CRD.

Based on the comments and responses, Decision 2015/009/R was developed.