NASA's thrust-vectoring-equipped McDonnell Douglas (MDC) F-15 is expected to have its first flight at Edwards AFB, California, around 1 February, following the successful completion of "hot-load" tests on the engines and vectoring nozzles.
The modified F-15 will be used to evaluate the performance benefits of thrust-vectoring under phase one of the Advanced Control Technology for Integrated Vehicles (ACTIVE) programme, a NASA-led effort involving the US Air Force, MDC and Pratt & Whitney. A second phase, scheduled for 1997/8, may involve "clipping the tails" of the F-15 to further reduce drag while compensating for the loss of control with thrust vectoring.
Key to the effort is P&W's axisymmetric, multi-directional, pitch-yaw balanced-beam nozzle (PYBBN), which was first ground tested in 1992 on a F100-229 engine. The former short take-off and landing/manoeuvre technology-demonstrator aircraft was fitted in 1994 with two 130kN (29,000lb) thrust F100-229 engines and the PYBBN, in readiness for testing in the fourth quarter of the year. Phase one of the ACTIVE was delayed, however, when the US Government shut down and NASA was furlonged for the period. Around 100 flights are planned during 1996 and into mid-1997.
" The prime objective of phase one is cruise optimisation," says Roger Bursey, P&W programme manager for advanced military engines and advanced vectoring systems. Most of the drag reduction is expected to be gained by using thrust vectoring to maintain pitch control.
General Electric is to qualify the F110-129 engine on the MDC F-15E and will install two powerplants on a test version of the aircraft at Edwards AFB, California, in the last week of January. GE has been actively pursuing a chance to qualify the engine as an established option for the F-15 since 1992. The GE powered F-15 is expected to have its first flight by the second week in February.
Source: Flight International
