When Manassas, Va.-based Aurora Flight Services started designing the 150-foot wing for Boeing’s Phantom Eye High Altitude Long Endurance (HALE) aircraft demonstrator, winning awards for innovation was not among its priorities, which were to design, manufacture and test a low-weight, high-stiffness structure, arguably the largest that was ever created using out-of-autoclave (OOA) composite materials with a unique and highly efficient airfoil.
However, Aurora Flight Services recently garnered awards from Aviation Week & Space Technology and Defense Technology International for producing the overall most innovative product and as the winner in the Company Less Than $80 million in Revenue Category.
The wing was designed at Aurora’s Manassas, Va., location, and fabricated and tested at its Columbus, Miss., location. According to Phil Chu, program manager for Aurora, there were three major innovations achieved in the wing build:
- The wing component was designed to employ low-cost tooling more common to marine applications using industrial materials than those typically used in the aerospace industry.
- For certain parts, OOA materials allowed modular ovens to be assembled over the lay-ups for cure instead of costly, very large, single-piece tools. The large tools could be laser located and secured to the floor, avoiding the need for large dolly fixtures.
- Full-scale testing to 100 percent design limit load was used to validate the design and analysis methodology. A dead mass of 13,000 lbs. was applied to the wing in the form of concrete-filled buckets suspended at multiple points. The buckets were drawn toward the center line to maintain the appropriate direction of the force. This method replaced a relatively complex whiffle tree, which would have been required for this class of high-aspect ratio wing. From a design standpoint, the force required is derived based on a combination of a safety factor with a required g load.