Designed For Manufacturability

The single-engine Falcon is 21 ft/6.4m long, with a 31.5-ft/9.6m wingspan. It can cruise at 140 mph (225 kph), burning less than 5 gal/18.9 liters of fuel per hour. For the North American market, VX Aero is maintaining the plane’s look and basic dimensions but also taking steps to improve its structural design.

 

Because the plane’s defunct creator’s design data were unavailable, development began with white-light 3-D digital scanning of the entire aircraft (using a structured-light scanner rather than a laser scanner) from which it developed CAD surface models. Then came the critique: “Original production was most likely using hand-built masters and tooling,” says Skillen. The fuselage had a significant amount of asymmetry. There were butt-jointed cored panels without any means for load transfer and a lack of hard points for structural connections. The construction scheme needed improvement, and it would be necessary to optimize the design for manufacturability. “Quality and efficiency had to be designed into every assembly and process,” he says, “to control costs and cycle time in an actual production environment.”

 

In pursuit of those goals, VX Aero is employing the concept of ‘self-rigging subassemblies’ in the Falcon’s design. For example, the heart of the airframe is a carbon fiber-reinforced plastic (CFRP) spar box. As the anchor component of the wingbox assembly (see top of p. 57), its outer mold line (OML) surfaces align with and locate those of the next higher assembly. This helps to minimize the cost and complexity of assembly fixtures yet hold tight tolerances.

 

The new wingbox assembly also addresses an issue in the original aircraft. Namely, landing gear loads were directly imparted to the fuselage with no load path carry-through from one side to the other. And because the large fuselage cutout for the polycarbonate cockpit canopy is located directly above the region that absorbs gear loads, this structural configuration resulted in unacceptable deflection. To compensate, VX Aero redesigned the forward and aft seat beams as key elements of the wingbox assembly. They are now attached through the wing roots to the spar box, which now provides the primary load path for the wing moments.