LAS VEGAS - A professional engineer who specializes in air quality says he found fatal flaws in federal plans for a weapons test that U.S. officials say will generate the first mushroom-shaped dust cloud in decades at the Nevada Test Site.A draft environmental assessment on the "Divine Strake" test didn't look at the likelihood that the smallest measure of dust and debris, 2.5 microns, could be churned up and sent airborne, Algirdas Leskys said."The modeling is inaccurate," said Leskys, 44, a data analyst with the Clark County Department of Air Quality and Environmental Management who stressed that he was not …