USAF-MERC Team Redesigns Critical B-2 Bomb Release Mechanism
The Bomb Rack Unit (BRU)-52 carries, monitors, and releases Mark 82 bombs on the B-2 Stealth Bomber. A small team of Air Force and MERC engineers redesigned critical components of the BRU-52 to improve its safety and reliability. Working with government engineers at various locations, the USAF-MERC team established functional requirements and limitations of the BRU-52 mechanisms. The B-2 system program office, Armament Sustainment Division Engineers and Equipment Specialists, and MERC engineers conducted on-site surveys at Whiteman AFB and Hill AFB with the end users to capture operational requirements and concerns. The final design modification added a mechanical shear pin that precludes unintended bomb release by physically restraining hook release movement from the loaded position.
In addition to the above concerns, the USAF-MERC team noted that repetitive, routine load training can damage the rear frame brace of the BRU-52, obstructing hook movement to the final locked position. MERC designed a more durable brace replacement that resolves the damage problem. This design modification also increased the BRU-52 safety and reliability.
In a twelve-month timeframe, MERC completed a thorough design review, stress analysis, and material/component testing for the new shear pin and rear frame brace. MERC designed and fabricated fixtures, jigs, and tooling to facilitate the BRU-52 precision modification process in a repeatable and accurate fashion.
In addition to the modifications to the BRU-52, MERC reverse-engineered the Hill AFB one-of-a-kind test equipment for the critical Time to First Motion Measurement, part of the BRU-52 testing required after the rack is overhauled. A new design was made using modern electronic components and was packaged in a small ruggedized portable case suitable for field testing.
The BRU-52 contract allowed MERC engineers to assist the government and supplement the Armament Sustainment Division at RAFB with the investigation and solution development for preventing unintentional release from the bomb rack. The program is an example of how the IDIQ fosters technical collaboration between the United States Air Force and MERC engineers to develop effective solutions for time-sensitive problems.
