Tier 1 Engineering Accomplishes Historic Battery-Powered Full-Size Helicopter Flight At Los Alamitos Army Airfield PR Newswire (press release) COSTA MESA, Calif., Sept. 30, 2016 /PRNewswire/ -- Tier 1 Engineering announced today that its battery-powered manned helicopter program achieved a successful first hover on Tuesday, September 13th, a first hover taxi on Wednesday, September 14th ... |