The only reason I can see for using crimped connectors on aircraft would be the tendency of solder to wick up the stranded wires, which would stiffen them, making them easier to break under vibration. Other than that, wire doesn't know whether it is held in place by a crimp or solder, and a crimp connection would be succeptable to the same stresses as a soldered one if it weren't for the wicking effect of solder.

In audio use, I have had dozens of crimped connections become intermittent over the years, yet not one soldered connection has ever given me one bit of problem, even ones I made in the 1960s. The metal in a crimp connection can bend both ways, and loosen it's tension over time, expecially if done with the low quality crimp tools available to most consumers in hardware stores or places like RadioShack. Professional crimping tools are very expensive, but make as good a crimp connection as is possible.

[This message has been edited by soundhound (edited October 29, 2003).]