Northern California residents are warned not to be alarmed as a very low flying helicopter scans for gas line problems. Over the next week a PG&E helicopter will be flying at 300 to 500 feet from Burney to Eureka and Redding to Butte County. It’s the utility’s semi-annual inspection of gas lines to be sure there’s no excavation or other potential dangers to the lines. Special equipment will be used to check for leaks.