Spotlight on industry: Military engines operation, GE aircraft engines

Sea Power, Jun 1998 by Little, Dennis R

Sea Power: GE is building the F414 engine for the Navy's new F/A-18E/F Super Hornet strike fighter. In what ways does that engine differ from the engine used in the AMB/C/D versions of the aircraft, and how will it improve the aircraft's performance?

Little: The F414 engine for the Super Hornet provides 35 percent more thrust than our F404 engine powering the earlier F/A-18 models without increasing the overall length of the engine. The engine's thrust-to-weight ratio is in the 9 to 1 class, and this contributes to increased aircraft payload. In both the fan and the compressor, we were able to achieve substantial performance improvement and incremental engine cost and weight reduction by combining airfoils and disks into a single component, called a "blisk." The result was 484 fewer parts and a 53-pound reduction in weight.

F414 improvements in component life and maintenance simplification to the afterburner are going to reduce maintenance requirements in the field. The flameholder was designed to be replaceable on wing and provide at least five times the life improvement over earlier designs. Variable exhaust nozzle flaps and seals made from composite materials have twice the operational life of earlier all-metal designs.

An important focus with the F414 has been to incorporate the latest technology to provide enhanced life and maintainability. In everything we work on, overall life cycle costs to the customer are the key concern.

The F414 development program has been designated a "model" development program by the US. Navy. What were the drivers behind this success?

The Navy is quick to praise not only the development program for the F414 engine, but the development of the entire F/A-1 8E/F aircraft system. The overall program is on schedule, on budget, under weight. It is a development program which has been run very, very well from a Navy standpoint, a Boeing standpoint, and a GE standpoint. The key is the team approach. There has been open communication at all working levels, using common program metrics and data bases. No one worries about who is in the room; everyone just talks it out and goes forward. There are no hidden agendas.

What is the market potential for the F414, both domestic and overseas?

The F/A-1 8E/F will some day be an important export product for the U.S. Navy. We are all looking at it that way. The number of aircraft purchased by the U.S. Navy will depend, over time, upon the status of other military programs. We envision the Navy buying between 500 and 600 aircraft, and we will see where it goes from there. There could be an export number of similar proportion.

The F120 engine that GE is developing for the Alternate Engine Program for the Joint Strike Fighter represents a different and in some ways more complex challenge. In what ways does it represent another step forward in engine performance-.and what is its U.S. and overseas sales potential?

The F120 will be fully developed about 10 years after the F414 was developed, so the engine will incorporate the latest technology in terms of materials, manufacturing capabilities, and advanced aerodynamics. For example, you will have a better thrust-to-- weight ratio compared with current engines. The engine will have a different mission, so it will look quite a bit different. Primarily, you will have manufacturing technology and materials in the early part of the 21st century not available today which will be incorporated into the engine. In terms of sales potential, you can see numbers as high as 3,000 domestic JSF aircraft and another 1,500 export aircraft. Our objective is to have a viable share of the engines for that market.

Your company spends millions annually in metallurgical and composites research. Do you see any breakthroughs leading to even more advanced engines by 2025 or 2050?

A key area will involve taking advantage of the newest advanced materials that are becoming available, such as composites and metal matrix composites, and better learn how to analyze them and use them to their fullest extent. Another area involves advancing the manufacturing technologies utilized in producing these materials in order to make them more affordable to the customer. This is key because, with a lot of these materials, the only people who use them are us, the engine manufacturers. As a result, there are not large quantities of these materials being produced.

In the field of marine engines, the LM2500 is one of the greatest industrial success stories of this century. How many LM2500s has GE delivered to how many navies-and for installation on how many ships?

The LM2500 is held up as the industry standard among the aeroderivative engines. Everybody would like to have at least one engine like that in their stable. We have about 1,500 engines delivered for marine and industrial applications. The LM2500 powers surface ships in 24 navies around the world, including all the surface combatants produced for the U.S. Navy today. As many engines as we have sold for ships, we have sold as many for industrial use. So, while the navy/marine market for the LM2500 has fallen off, the industrial market has picked up and we make more LM2500s today than we did back when the U.S. Navy was building six destroyers a year instead of three.