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Drilling fastener holes in large assemblies is traditionally accomplished through the use of large machine tools in order to obtain the accuracies required for the assembled part. Given recent advances of machine design and machine controller compensation, the accuracy of the motion platform can be corrected if the machine is repeatable. This coupled with the use of a vision system or touch probe to compensate for assembly variations, permit the use of smaller, more portable drilling systems. These smaller, more portable machine tools allow for lean manufacturing techniques to be incorporated into build processes, utilize less floor space, and in many cases are less costly than larger, permanent machine tools. This paper examines the feasibility of utilizing a small 5-axis, portable, drilling system for drilling the side panel skins on the F/A-18 E/F forward fuselage.

Electromagnetic forming (EMF) technology has been used lately for the joining and assembly of axisymmetric parts in the aerospace and automotive industries. A few case studies of compressive-type joining processes applied on both aluminum and titanium or stainless tubes for aerospace applications are presented. In the first case study, tests were conducted using 2024-T3 drawn tubes joined with a steel end fitting to form a torque tube using different forming variables including: the fitting geometry, material formability and forming power (KJ). The power setting and the fitting geometry were optimized to improve the fatigue life, torque off, and the axial load capability of the torque tube joints to drive the leading and trailing edge high-lift devices.

Titanium’s high strength-to-weight ratio and corrosion resistance makes it ideal for many aerospace applications, especially in heat critical zones. Superplastic Forming (SPF) can be used to form titanium into near-net, complex shapes without springback. The process uses a machined die where inert gas is applied uniformly to the metal sheet, forming the part into the die cavity. Standard titanium alpha-beta alloys, such as 6Al-4V, form at temperatures between 900 and 925°C (1650-1700°F). Recent efforts have demonstrated alloys that form at lower temperatures ranging between 760 and 790°C (1400-1450°F). Lowering the forming temperature reduces the amount of alpha case that forms on the part, which must be removed. This provides an opportunity of starting with a lower gauge material. Lower forming temperatures also limit the amount of oxidation and wear on the tool and increase the life of certain press components, such as heaters and platens.

The new materials and material combinations such as composites and titanium combinations used on today's new airplanes are proving to be very challenging when drilling holes during manufacturing and assembly operations. Orbital hole drilling technology has shown a great deal of promise for generating burr free, high quality holes in hard metals and in composite materials. This paper will show some of the orbital drilling development work Boeing is doing with Novator to overcome the obstacles of drilling holes in a combination of both hard metals and composites. The paper will include a new portable orbital drilling system designed for these challenging applications as well as some test results achieved with this system.