Crash survivable enclosure for flight recorder

Abstract

A crash survivable enclosure for flight data recorders used in aircraft and other vehicles operating over land and water includes a strong, light-weight metal shell for enclosing and protecting an information storage device having power, signal, and address lines connected thereto. The memory device is supported inside the shell in a wax filler of the type having a high melting temperature and a high heat of fusion to act as a heat sink for absorbing a large quantity of heat to minimize possible damage to the memory device because of excessive heat, flames and/or high temperature. A strong lightweight metal shell is provided to enclose and protect the inner shell and contents against substantial, external mechanical forces commonly occurring in a crash and flames, heat and fire resulting therefrom. A second filler of high efficiency, heat insulating material is provided for physically supporting the inner shell and contents and for providing protection against flame, fire and heat penetration as well as physical impact and shock penetration as would be encountered in a crash of an aircraft or other vehicle carrying the enclosure. The enclosure is especially designed to withstand prolonged immersion in salt water at substantial depths to provide protection against damage to the memory device so that pertinent recorded information is available upon retrieval of the enclosure after a crash.