IRVINE, Calif.—The Orange County Fire Authority Thursday announced it had approved the acquisition of two new firefighting helicopters. The new Sikorsky S70 Firehawk helicopters were approved by the authority’s board a week ago. The new helicopters replace the authority’s 1966 UH-1H “Super Hueys” which had become too expensive to maintain. A Sikorsky S70 Firehawk helicopter….