Lu, all you said was true about static electricty. And you also mentioned the reason for the static discharge wick. If that were the case the thing would quit "sparking" upon touch down, but that is not the case. They still spark, and even more so when pitch is pulled. BUT that is not why they tend to "spark" when hovering close to the ground in the desert. It is because of the sand particals hitting the leading edge which is a metal hybrid. (erosion strip is there for that reason, it erodes) The tail rotor has no such strip thus does not spark. The AS350 is all composite, does not spark. It still has the same static buildup obviously. You still have to discharge it before you touch it before commencing hoist ops. But no "sparks" when flown in the desert enviroment,below ETL and close to the ground. (ie hovering)
j