Pratt & Whitney has begun tests of a new area-ruled fan blade on the F100-299A fighter engine as it closes in on the final configuration for design verification tests by the end of the year.

The new blade design is derived from computational fluid dynamics work conducted on the larger F119 and represents the first application of the concept on any member of the F100 family. The root of the blade is scooped out to produce an area ruling effect, thereby reducing "blockage" of airflow at the hub.

The modification is expected to improve flow performance, which has already been raised to 616kg/s (280lb/s), and to help sustain a maximum sea level equivalent thrust of 32,500lb (143kN) in afterburner and 20,100lb dry. In trials, the -229A has generated more than 37,000lb thrust.

The engine is to begin endurance qualification tests in mid-2000, before the start of initial production in 2001. The fifth generation -229A is aimed at current and future Boeing F-15s and Lockheed Martin F-16s, while key components such as the fan module and fan duct are being developed as a retrofit upgrade kit for the -229.

P&W is offering the new engine, and the -220/229, for competitions in Chile, Greece, Israel, New Zealand, Norway and the United Arab Emirates.

A USAF executive engine independent review team says that the F100-229 programme is back on track after recovering from a serious spare parts shortage at Royal Air Force Lakenheath. The F-15E UK base was below the minimum spares requirement for more than a year, but reached the required level in October.

The problem will be officially considered as having been solved if this margin can be continued at or above this figure for six consecutive months. The base is expected to be back to normal operations by mid-April.

The team found that, at Laken-heath, the engine was subjected to tougher mission requirements than originally expected. As a result, engine life was used more quickly than projected, causing maintenance problems as spares were supplied faster than planned.

Source: Flight International