The largest commercial helicopter factory in the world is sandwiched between strip malls along PCH and a tiny municipal airport in Torrance. Twice a week, Robinson Helicopter opens its doors for a free 60-minute public tour. Slag metal arrives at one end, and the finished choppers fly out the other. Enormous waterjet cutters spray alongside goggled women soldering circuit boards. Eleven hundred employees scurrying across several acres of factory floor give you plenty to observe, but don’t bring your camera. They have been forbidden ever since one tourist snapped pics and used them to create a doomed homemade aircraft.