In article .net,
says...


As one who trained mechanics to taxi jets.......
No license required but a "run card" is required. Classroom, Simulator
and practical. Basically an authorization from the company to perform
the operation specified.
Michelle



This famous incident comes to mind :-)
http://www.airliners.net/open.file/050163/M/

I don't know what the final cause was determined to be, but at the time
there was some consternation expressed about the fact that the mechanic
was operating the plane (on the ground). Of course, this was not in the
US - and I only said there was concern expressed, not thta this was
determined to be causal or contributing to the result . . .

G Faris