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

5.1.6.8 Additional release operation interrupts. If any additional release interrupt devices are required, they shall not defeat the functions of the safety interlock mechanism (i.e. the removal of any additional interrupt while the safety interlock is in the ARMED state shall not result in an inadvertent release operation of the BRU). Additional interrupt designs shall consider any single point safety requirements.

5.1.7 Store release and ejection system. Primary store ejection release shall occur at all aircraft attitudes within the release envelope with all store restraining mechanisms removed simultaneously and the vertical supports driven to the release position by compatible sequencing of the release and store ejection mechanisms (STANAG 3575 and AIR STD 20/10). The store ejection velocity, release attitude, and resultant reaction forces shall be applied through the ejector system except in its gravity release mode, or the BRU may be designed as a gravity release device only. Both ejector BRUs and gravity release BRUs may be actuated/powered by impulse cartridges, pneumatic pressure or hydraulic pressure. Electrical power shall be used to ignite the cartridges, or electrical power shall be used to operate solenoids to activate pneumatic or hydraulic pressure. A gravity release BRU may also be actuated/powered by other means that directly drives its vertical supports to the release position.

5.1.7.1 Gravity release BRUs. For gravity release BRUs, requirements for ejection force, reaction loads, separation velocity, and ejector pistons do not apply. All other requirements shall apply.

5.1.7.2 Pyrotechnic actuated BRUs. If cartridge(s) are used, the release and ejection system shall be initiated remotely by independent aircraft electrical sources (primary and secondary). Independent initiation circuits shall follow separate wiring to the cartridges. The BRU shall

allow for the simultaneous initiation of both impulse cartridges from either electrical source as detailed in Figure 4. The BRU shall provide for the sympathetic ignition (ignition of one cartridge shall ignite the other) of either impulse cartridge by the other without sacrificing ejector performance.

5.1.7.2.1 Cartridges. If cartridges are employed in the ejector system, the cartridges and ejector system shall be designed, but not limited, to the following requirements:

a. Two cartridges shall be utilized as a minimum.

b. The ejector system shall be actuated by the initiation of any combination of cartridges as specified by the procuring activity.

c. Cartridge interface and utilization shall comply with MIL-D-81303. (Cartridge geometry is specified in MIL-D-81303.)

d. Cartridge power sources shall provide a minimum of 3 amperes at 28 VDC and meet the requirements in MIL-STD-704, for normal and emergency operation. Each power source shall