The Lockheed Electra was the first turbo prop passenger aircraft to enter service in the U.S. It was a highly capable aircraft and enjoyed initial success. But two highly publicized, fatal crashes revealed a structural flaw in the engine mounts. The flaw was quickly corrected, but no further orders were forthcoming, as the airlines had laost faith in the aircraft. Oddly enough, it went on to become the basis for the hugely successful P-3 Orion naval patrol aircraft.