Join Cell for the G150 Aircraft

Abstract

A simple, open, post and index system is used for final alignment and joining of the fuselage and wings of a new passenger business jet. 19 manually actuated axes precisely move the wings, forward, and rear fuselage sections into position. Movement is accomplished with industrial jacking screws and positions recorded with precision linear potentiometers. Wing sweep, angle of attack, and dihedral are monitored and controlled. The axes positions are downloaded to data files for verification and data archiving. The Gulfstream G150 Join Cell’s open architecture enhances access to fasten the main aircraft structure while maintaining flight critical geometry. INTRODUCTION The Gulfstream G150 is an all new, high-speed, midsize, business jet. With program launch in 2003, the structure assembly and all system installations are done in Israel by Israel Aircraft Industries (IAI). IAI has built a number of business aircraft, including the Westwind series, Gulfstream G100 (Astra) series, and the Gulfstream G200 (Galaxy) currently in production. The G150 fuselage structure is largely made out of aluminum alloy. Design and build of the assembly fixtures for the new G150 aircraft was subcontracted to Electroimpact. In addition to the fixed tooling of this aircraft, IAI and Electroimpact conceived and built a simple, unique Join Cell for the final wing and fuselage join of the whole airframe. See Figures 1, 2, and 3. Traditionally, the aircraft structure joining operations are the most complex and therefore the longest in terms of the required labor hours. In order to reduce assembly cost, large commercial airframes are joined using expensive automatic laser alignment systems. These systems are sensitive to the assembly floor environment and are complicated for production personnel. Automatic laser alignment system’s cost exceeds many hundreds of thousands of dollars. The described manual Join Cell is perfectly suits mid-size business jet assembly needs. The main purpose of the Join Cell is to provide accurate positioning for the wings and fuselage sections. See Figure 4 for the axes positioning capabilities of the join cell. Other important aspects of the join cell include 1. An “open” post-type architecture to facilitate access to the wing fuselage joints for drilling and fastening. 2. Intuitive, jack-screw-assisted manual movement of the aircraft sections. 3. 19 axes of jack-screw assisted motion for moving fuselage and wing sections into the correct positions. 4. Accurate measurement and adjustment of the wing tips for sweep, angle of attack, and dihedral. 5. Accurate location of the rear engine mounts 6. The ability for gross movement (1 meter) of wings and fuselage sections apart to assist cleaning and deburring. 7. The ability to easily move the wings and fuselage sections back to a previously established position. 8. An electronic method of verifying and recording each axes join positions. 9. Process improvement by verifying and reviewing final join positions aircraft-to-aircraft. Figure 1. G150 Join Cell Overall Model Figure 2. G150 Join Cell overall side photograph Figure 3. G150 Join Cell overall front photograph G150 JOIN CELL DESCRIPTION The join cell attaches the following major subassemblies of the G150: • Fixed, center fuselage section. This section consists of the Carry Through Structure (CTS), over-wing section of the passenger cabin and the integral fuel tank structure. • Forward fuselage section including the forward passenger cabin, cockpit and nose landing gear. • Rear fuselage section including engine mounts • Left and right wings The center fuselage section is securely mounted and fixed through the CTS in the jig. See Figures 4 and 5. The other four assemblies are mounted on moving jig tooling and maneuvered into place with hand cranked, precision, screw actuators. Figure 4. Center Fuselage Section loading into join cell, front view Figure 5. Center Fuselage Section loaded in join cell, side view