Advanced Composite Cargo Aircraft Makes First Flight

  • Published
  • By Air Force Wing Public Affairs
  • AFRL Headquarters
WRIGHT-PATTERSON AIR FORCE BASE, Ohio. --  The famed "Skunk Works®" advanced development program launched a new era of aircraft manufacturing technology and performance with the successful flight of the Advanced Composite Cargo Aircraft, a vehicle developed jointly by Air Force Research Laboratory and Lockheed Martin. Conducted at US Air Force Plant 42 in Palmdale, Calif., the successful flight marks the final--and most significant--milestone of the AFRL ACCA Phase II program, validating the efforts of countless researchers across the country towards fundamentally changing the way airframes are made. The event culminates years of teamwork between government and industry labs dedicated to reinventing the manufacturing paradigm through the strategic use of composite manufacturing technologies. 

The ACCA is a modified Dornier 328J aircraft. Engineers removed the fuselage aft of the crew station and the vertical tail of the original craft, replacing these components with completely new structural designs based on advanced composite materials fabricated using out-of-autoclave curing. The ACCA fuselage is wider and stronger in order to accommodate military-standard 463L pallets; it also features a cargo door and cargo ramp. The vertical tail features integrally stiffened skin. Despite the ACCA's larger size, the materials and processes used for the fuselage drastically reduced the number of parts (by an order of magnitude relative to the original metallic design, or approximately 300 versus 3,000 parts), as well as the number of mechanical fasteners (about 4,000 versus 30,000). 

Manufacturing of the new composite structure occurs without complex tooling, and the bonding process yields a 90% reduction of structural components and fasteners. Lacking traditional fasteners such as rivets, the composite structure is inherently aerodynamic. It will address many of the corrosion and aging issues associated with all-metal aircraft, reducing airframe lifetime maintenance. Further, the structure's lighter-weight, composite materials will contribute to increased cargo capacity and aircraft performance, along with lower operating costs. This maturation of manufacturing processes will collectively reduce the cost and complexity of building large airframes. 

A 10-year, AFRL-led research and development investment known as the Composite Affordability Initiative enabled the ACCA's first flight, marking the capstone test of CAI principles integration, from conceptual design through certification and flight.