AMC E 1050 Exposure to volcanic cloud hazards

Acceptable means of establishing the susceptibility of Engine features to the effects of volcanic clouds should include a combination of experience, studies, analysis, and/or testing of parts, sub-assemblies or Engines. Information necessary for safe operation should be contained in the relevant documentation. This information may be used to assist operators in producing operational data and instructions for their flight crews when operating in, or avoiding, airspace contaminated with volcanic clouds. The information should be readily usable by operators in preparing a safety risk assessment as part of their overall management system. A volcanic cloud comprises volcanic ash together with gases and other chemicals. Although the primary hazard is volcanic ash, other elements of the volcanic cloud may also be undesirable to operate through, and their effect on airworthiness should be assessed. In determining the susceptibility of turbine Engine features to the effects of volcanic clouds and the necessary information to operators to allow safe Engine operation, the following points should be considered:

(1)Identify the features of the turbine Engine that are susceptible to airworthiness effects from volcanic clouds. These may include but are not limited to the following: a. erosion of compressor blades and other internal parts; b. glassy deposits on hot section parts, which can result in loss of surge margins, Engine stall, flame out, and inability to restart Engines; c. clogging of turbine blade cooling channels; d. corrosion of metallic parts; e. oil and fuel circuit contamination; and f. electrical, hydraulic and pneumatic systems.

(2)The nature and severity of effects.

(3)The related pre-flight, in-flight and post-flight precautions to be observed by the operator including any necessary amendments to Engine Manuals, Dispatch Deviation, or equivalents, required to support the operator.

(4)The recommended continued airworthiness inspections associated with operations in volcanic cloud contaminated airspace; these may take the form of Instructions for Continued Airworthiness or other advice.

[Amdt. No. E/4]