As of 2009, the F414-EDE was being developed and tested, under a United States Navy contract for a reduced specific fuel consumption (SFC) demonstrator engine. In addition, General Electric has tested F414 engines equipped with a second low-pressure turbine stage made from ceramic matrix composites (CMC). The F414 represents the first successful use of a CMC in a rotating engine part. The tests proved CMCs are strong enough to endure the heat and rotational stress inside the turbine. The advantage CMC offers is a weight one third that of metal alloy and the ability to operate without cooling air, making the engine more aerodynamically efficient and fuel efficient. The new turbine is not yet ready for a production aircraft, however, as further design changes are needed to make it more robust.