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)

3.3.6 Module retainer. The retainer mechanism is permitted to be part of the enclosure or

part of the module. The retainer mechanism shall be capable of securing SEMs firmly in place

with a minimum contact pressure of 25 pounds per square inch (psi). This mechanism shall be

shop and depot adjustable or replaceable. The retainers for the Format C or E modules shall not

contribute to the insertion or extraction forces.

3.3.7 Escape of fluids. The enclosure shall contain a means of allowing the escape of fluids,

such as drain holes. The rack shall be capable of being mounted in any orientation and shall be

designed to avoid any feature which traps water or other fluids.

3.3.8 Heat exchanger. The heat load shall be removed by the heat exchangers through

forced-air cooling.

3.3.9 Throttling. The rack shall provide a mechanism for throttling the air flow through each

heat exchanger. This mechanism shall be shop and depot adjustable or replaceable.

3.3.10 Time elapsed meter. The rack shall accommodate installation of a time elapsed meter.

3.3.11 Interchangeability.

3.3.11.1 Design tolerances. Design tolerances shall permit parts, subassemblies, and

assemblies, having the full range of dimensions, to be used in their parent assemblies without

regard to the source of supply or manufacturer.

3.3.11.2 Parts and materials. When the specification for the part or material contains

substitutability or supersession information, the design shall permit parts or materials to be used

interchangeably.

3.3.11.3 Interchangeability conflicts. In event of a conflict between any of the requirements

of this specification, the interchangeability requirement shall govern.

3.3.12 Dummy module. The rack shall be capable of accepting dummy modules.

3.4 Performance characteristics.

3.4.1 Environmental. The rack shall be designed for the environmental conditions specified in

table I and shall operate in these conditions with no degradation of performance or change in

physical form.