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

d. AU locations shall permit easy insertion and removal of standard arming wire swivel and ring assemblies, NAVAIR drawing 923AS190, with the store restrained.

e. Shall not be susceptible to inadvertent operation due to shock, vibration, or store ejection per MIL-T-7743.

f. Shall retain arming wire loops after an "armed" drop, even after the BRU is de- energized, until arming wire loops are manually removed.

g. The AU shall be located on the BRU lower longitudinal centerline.

h. The centerline of the AU arming loop retaining mechanism shall be positioned such that it allows for the installation and removal of arming loop with store present.

i. The mechanical fuze AUs shall be located as shown on Figures 1, 2, and 3.

j. Each AU shall operate reliably at a nominal 28 volts direct current (VDC), at a maximum of 250 milliamperes per MIL-STD-704 normal operation voltage range.

k. A temporary voltage surge, up to ±45 VDC maximum, across the arming unit power input terminals shall not damage the AU's ability to operate properly and shall conform to the requirements of 5.1.9.2.

5.1.4.2 Electrical fuze AU. Electrical fuzing is a Department of Defense unique item. When required by the procuring activity, the BRU shall provide an electrical fuze AU as specified in MIL-C-81842 at the location as shown on Figure 1 and Figure 2 to ensure compatible electrical fuze functioning with the MK 122 arming safety switch as specified in NAVAIR WS-2081. There shall be an interlock function provided between the BRU release linkage and fuze charging line, whereby the electrical AU senses correct linkage movement representing properly intended store release, before the electrical pulse shall be permitted to enter the electrical fuze connector. The electrical fuze arming circuit shall be such that the predominant failure mode of the electrical fuzing shall be in the fail-safe mode (not fuzed). The fuze circuit shall be designed such that a hung store by either vertical support shall not arm/fuze the device. Adjacent to the electrical arming unit shall be a positive arming attachment (see

5.1.4.3) compatible with the MK 122 arming safety switch. Vertical access and clearance shall be provided to permit MK 122 arming safety switch connection to the electrical AU by hand with the store latched and restrained.

5.1.4.3 Positive arming attachment. Unless otherwise specified by the procuring activity, a minimum of four positive arming attachments shall be provided. They may be located on both sides, or one side, of the BRU along its entire length (longitudinal axis) as shown on Figures 1 and 2. The location of the positive arming attachments with installed arming wires shall not