Out-of-Autoclave Composites Apache Secondary Structures

The Boeing Company in Mesa, Arizona has been collaborating with The Boeing Company in Philadelphia, Pennsylvania in the study of the use of Out-of-Autoclave (OOA) formulated composite pre-impregnated (prepreg) materials for aircraft composite parts fabrication. Currently, The Boeing Company in Mesa, Arizona is using primarily autoclaves for curing composite parts. Autoclave cure processes have higher tooling and capitalization cost, whereas oven cure processes have lower tooling cost and considerably lower investment cost for capital equipment. New prepreg composite materials have been developed and formulated specifically for oven cure utilizing vacuum bag only for conforming material to the tool and for the evacuation of air and volatiles during cure. These materials are of intermediate modulus carbon fabric in toughened epoxy resin. The primary goal is to convert as many secondary structures composite parts as possible from autoclave cure materials to oven cure with the exemption of those parts that are located in aircraft survivability zones. This conversion will give manufacturing the option to optimize curing resources for better equipment utilization, lower operational cost, and shorter fabrication flow times. As an added advantage the conversion to carbon fiber OOA materials will result in reduced part weight which is a very desirable part property in rotorcraft.