According to this ;
;
aluMATTER*|*Aluminium*|*Wrought Aluminium Alloys*|*Examples of Applications
7449 is a wrought alloy.
Reading the assembly description, it seems that this is a new process ;
Higher Levels of Automation Lift Productivity for Airbus A380 Wing Assembly Process
" For the Airbus A380 panel-production facility, Electroimpact built four machine lines, each with two machines for upper and lower surface panels. Each line includes three fixtures, where four panels are loaded. The jigs hold the components in accurate form and location while the automated machines drill, rivet, and bolt the components together. Sealant is applied to the components during the jig load. No temporary fasteners are used.
Thus, after fastening, the wing panel assemblies are complete. No interim operations are needed to clean and deburr. The one-up assembly process reduces handling damage and positioning inaccuracies (datum errors). The machines can install rivets and bolts in diameters of ¼ to ½ in., with a stack range up to 2.5 in. Automated cold working, hole probing, countersink sealing, and collar installation are all included. "
[quote]
" In the region of rib 26 and stringer 21, larger-than-expected gaps - some 1.5-2mm rather than 0.5mm - between the sections involved in the pull-down had resulted in stresses being induced, leading eventually to cracking under the wear of normal airline operations. " [quote]
Are the hole tolerances such that with a 2.0 mm gap lateral forces from fastener misalignment could also be introduced ?