General Electric F414
First run on 20 May 1993, GE evolved the F404 into the F412-GE-400 non-afterburning turbofan for the A-12 Avenger II. After the cancellation of the A-12, the research was directed toward an engine for the F/A-18E/F Super Hornet. GE successfully pitched the F414 as a low-risk derivative of the F404, rather than a riskier new engine. In fact, the F414 engine was originally envisioned as not using any materials or processes not used in the F404, and was designed to fit in the same footprint as the F404.
The F414 uses the core of the F412 and its full-authority digital engine control (FADEC), alongside the low-pressure system from the YF120 engine developed for the Advanced Tactical Fighter competition. One of the major differences between the F404 and the F414 is the fan section. The fan of the F414 is larger than that of the F404, but smaller than the fan for the F412. The larger fan section increases airflow by 16% and is 5 inches (13 cm) longer. To keep the engine in the F404's footprint, the afterburner section was shortened by 4 in (10 cm) and the combustor shortened by 1 in (2.5 cm). Another change from the F404 is the fact that the first three stages of the high pressure compressor are blisks rather than dovetailed blades, saving 50 pounds (23 kg) in weight. Furthermore, the FADEC guided F414 uses a fuel actuated system to manipulate the afterburner section rather than a separate hydraulic system.
The F414 continued to be improved, both through internal GE efforts and federally funded development programs. By 2006 GE had tested an Enhanced Durability Engine (EDE) with an advanced core. The EDE engine provided a 15% thrust increase or longer life without the thrust increase. It has a six-stage high-pressure compressor (down from 7 stages in the standard F414) and an advanced high-pressure turbine. The new compressor should be about 3% more efficient. The new high pressure turbine uses new materials and a new way of delivering cooling air to the blades. These changes should increase the turbine temperature capability by about 150 °F (66 °C). The EDE is designed to have better foreign object damage resistance, and a reduced fuel burn rate.
The EDE program continued with the testing of an advanced two stage blade-disk (Blisk) fan. The first advanced fan was produced using traditional methods, but future blisk fans would be made using translational friction welding with the goal of reducing manufacturing costs. GE touts that this latest variant yields either a 20% increase in thrust or threefold increase in hot-section durability over the previous F414. This version is called the Enhanced Performance Engine (EPE) and was partially funded through the federal Integrated High Performance Turbine Engine Technology (or IHPTET) program.
Over 1,000 F414 engines had been delivered and the engine family has totaled over 1 million flight hours by 2010.