MIL-STD-2088-SUP-2 Bomb Rack Unit BRU, Single Store, AircraftThis standard establishes the general guidelines and criteria for the design and development of a single store bomb rack unit BRU for carriage and release of airborne stores excluding air-to-air missiles from fixed wing and rotary wing aircraft using a single suspension point or suspension points spaced at 14 or 30 inches. This standard addresses detailed requirements for gravity non-ejected, pyrotechnic, hydraulic, and pneumatic powered BRUs. Mechanical aircraft armament interoperable interfaces are incorporated to enhance cross utilization and servicing capabilities between military aircraft and aircraft stores see 3.1 of all services of the Department of Defense DoD and North Atlantic Treaty Organization NATO nations.

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MIL-STD-2088B

4.3.3.5 Cyclic loads. The BRU shall be capable of withstanding the cyclic application of combined limit loads imposed upon it over the course of its specified life. The cyclic load spectra shall include the effects of specified environments and a minimum of 500 launches.

4.3.4 Stress analysis. A stress analysis shall be accomplished by using the loads generated in accordance with 4.3.3. Calculated margins of safety less than 0.33 for cast items shall be demonstrated by structural test. Critical margins of safety shall be made available to the procuring activity.

4.3.5 Service life. The BRU design objective shall be to meet or exceed an economically maintainable service life of: "a" flight hours, or "b" ejections, or "c" operating hours, or "d" operating cycles, whichever occurs first. An economically maintainable service life is exceeded when the cost to repair the BRU is greater than one-half the replacement cost.

"a" - 6,000 or as specified by the procuring activity "b" - 500 or as specified by the procuring activity "c" - 9,000 or as specified by the procuring activity "d" - 2,000 or as specified by the procuring activity

4.3.6 Reliability. Mission reliability for a BRU shall be a minimum of 0.99. Mission reliability is the probability that the BRU will successfully eject stores within specified mission parameters.

4.3.7 Shelf life. Shelf life of the BRU and all components shall be a minimum of five years and shall be refurbishable following the minimum shelf life specified. Exclusive of shelf life, the service life of the BRU shall be a minimum of 10 years. A maximum number of parts shall have an indefinite shelf life and a service life not less than that of the BRU.

4.3.8 Interfaces.

4.3.8.1 BRU to aircraft interface. The BRU to aircraft interface shall be dependent on aircraft design and airframe backup structure to distribute the BRU stores load. The BRU mounting shall optimize the aircraft performance envelope, minimize weight and drag, and utilize optimum load paths. Design shall be tailored to existing aircraft support structure and shall provide ease of installation and removal. Physical interfaces between the BRU and the aircraft shall be defined in terms of dimensions and tolerances. Functional interfaces shall include the support, service, and ejection functions. Electrical interfaces shall specify BRU power and signal requirements. All interface requirements shall comply with aircraft interface specifications.

4.3.8.2 BRU to store interface. Interface between the BRU and store shall include stores support, retention and the pre-release, release, and service functions. Physical interfaces