Heat shielded memory unit for an aircraft flight data recorder

An enclosure for thermally protecting one or more heat sensitive items from a high temperature environment, said enclosure comprising:

• a metal outer housing including an interior cavity for containing said one or more heat sensitive items;
• a first thermal insulator configured as a thermal liner that extends about the surface of said first interior cavity, said thermal liner defining a second interior cavity with said one or more heat sensitive items being spaced apart from the walls of said second interior cavity said first thermal insulator being a solid material and remaining solid when said enclosure is exposed to a high temperature environment;
• and
• an amide wax, said wax occupying at least a portion of said interior cavity and encapsulating said one or more heat sensitive items said amide wax exhibiting a phase transition at a predetermined temperature, said predetermined temperature being selected to maintain said amide wax in a solid phase when said enclosure is not exposed to said high temperature environment and being selected to allow conversion of said amide wax to a liquid phase when said enclosure is exposed to said high temperature environment.