MIL-PRF-85725 Rack, Integrated Avionics, Forced Air Cooled, General Specification ForThis specification covers forced-air-cooled, integrated avionics racks, herein after referred to as racks, used for various military avionics systems. The racks are designed to accommodate Standard Electronic Modules \(SEMs\) using multiple tiers.

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MIL-PRF-85725A(AS)

(Application for copies should be addressed to the American Society for Quality Control,

611 East Wisconsin Avenue, Milwaukee, WI 53202.)

2.4 Order of precedence. In the event of a conflict between the text of this document and

the references cited herein, the text of this document takes precedence. Nothing in this document,

however, supersedes applicable laws and regulations unless a specific exemption has been

obtained.

3. REQUIREMENTS

3.1 First article. When specified (see 6.2), a sample shall be subjected to first article

inspection in accordance with 4.2.

3.2 Materials. The materials used in the construction of racks shall be capable of meeting the

performance requirements specified herein (see 3.3.11.2 and 4.5.1).

3.2.1 Corrosion prevention and control. The materials selected shall have corrosion

resistance or shall be treated to resist corrosion during service life (see 6.2).

3.2.2 Dissimilar metals. Where dissimilar metals are used in contact with each other,

protection against galvanic corrosion shall be provided. When dissimilar metals are used they

shall not be susceptible to galvanic corrosion in accordance with table VII of MIL-C-28754.

Dissimilar metals such as brass, copper or steel shall not be used in contact with aluminum or

aluminum alloys.

3.2.3 Recycled, recovered, or environmentally preferable materials. Recycled, recovered, or

environmentally safe materials shall be used, provided that the material meets the performance

requirements specified herein.

3.3 Design.

3.3.1 Modularity. The rack shall accommodate two to seven tiers (see 6.2). Each tier shall

be compatible with either Format B span 2, Format C, or Format E modules as specified in

MIL-STD-1389. Each tier shall also contain a primary backplane. The individual tiers shall

interconnect with a flexible secondary backplane. Each tier shall:

a. Have a primary backplane through which the SEMs are interconnected.

b. Have a combination module guide rail and air heat exchanger for module retention and

heat dissipation.