Tier 1 Engineering Accomplishes Historic Battery-Powered Full-Size Helicopter Flight At Los Alamitos Army AirfieldPR Newswire (press release)COSTA MESA, Calif., Sept. 30, 2016 /PRNewswire/ -- Tier 1 Engineering announced today that its battery-powered mann …

Tier 1 Engineering Accomplishes Historic Battery-Powered Full-Size ...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 ...and …