MIL-STD-2088 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

w/CHANGE 1

Swaybraces shall be designed so that they cannot apply excessive loads to the store or BRU to prevent store release. After all swaybraces have been activated, the store shall be held securely in all three axes until separation of the store. The application of the swaybraces at any point shall have a centering action on the store that tends to keep the store symmetric about the BRU vertical axis. The contact of the swaybraces to the store shall exhibit at least line contact on a store conforming to MIL-STD-8591. The swaybraces shall not require any scheduled maintenance nor be susceptible to damage by sand, dust, or supersonic airflow impingement. The swaybraces shall be capable of interfacing with stores having reinforced areas as specified in MIL-STD-8591.

5.1.6 Safety interlock. The BRU shall contain a safety interlock mechanism that interrupts both the BRU's electrical initiation control circuit and its mechanical store support latch release operation (STANAG 3575 AA). Each of the two interrupts shall be removed as a result of separate and distinct events as detailed in the following paragraphs. A mechanical store support latch interrupt is not required for frangible attach points.

5.1.6.1 Safety interlock status. The safety interlock mechanism shall have a minimum of two distinct position settings: SAFE and ARMED. If the BRU requires ground operation with stored energy present, then a third position, GROUND, may be required. With both the electrical and mechanical (when required) interrupts in place, the safety interlock shall be in its SAFE position. With both the electrical and mechanical interrupts removed, the safety interlock shall be in its ARMED position. With the electrical interrupt in place and the mechanical interrupt removed, the safety interlock shall be in its GROUND position. The BRU shall

provide both local and remote status indication of the safety interlock mechanism. Local status indication shall provide visual indication of the safety interlock mechanism's position. The position indicator shall be mechanically linked to the safety interlock and be visible from a distance of 15 feet (line of sight permitting) during daylight hours. The safety interlock shall only be capable of being set to the SAFE position with both store support(s) fully latched. For Types I and II BRUs, the BRU shall provide discrete signals to remotely indicate the status of

the safety interlock to the aircraft or aircraft systems monitoring equipment. The safety interlock status shall be sensed such that no single sensor failure shall provide the aircraft with an erroneous SAFE status.

5.1.6.2 Interrupt removal. During ground operations or during aircraft in-flight preparations for store release, the first event shall remove the electrical interrupt, and the second event shall remove the mechanical interrupt from the BRU allowing store support latch release operation. The first event shall not be permitted to occur unless the mechanical interrupt is in place. If sufficient energy is present on the electrical control circuit when the electrical interrupt is removed, initiation of the BRU store release may occur. If store release is initiated while the mechanical interrupt is still in place, a "Lock-Shut-Firing" of the BRU shall result. The mechanical interrupt shall be designed so that it cannot be removed by manual or automated means while the BRU is in the "Lock-Shut-Fire" state. The second event shall not be permitted