Optimized Repair Design: USAF HH-60G FS 308 Frame

Mercer Engineering Research Center (MERC) has designed, tested, and installed a structural repair for the United States Air Force (USAF) HH-60G Pave Hawk FS 308 frame. The USAF requested development of the repair in order to address frequent cracking in the fleet at the FS 308 / RBL 34.5 interface, which affects aircraft availability and drives higher depot maintenance costs. These cracks typically necessitate a replacement of the entire FS 308 frame, a depot-level task that is costly and time-consuming. The MERC-designed repair accomplishes the design objectives, eliminating the crack-prone tabs at the FS 308 / BL 34.5 interface while maintaining the stiffness of the original structure within 11% to avoid negative impacts to other areas of the HH-60G structure. This paper details the structural design and optimization methodology, analysis, testing, and installation of the HH-60G FS 308 frame repair.