PRATT & WHITNEY plans to ship axisymmetric thrust-vectoring nozzles for a McDonnell Douglas (MDC) F-15 to Edwards AFB, California, at the end of this month. A pitch/yaw balanced-beam nozzle (PYBBN) will be installed on each of the F-15's P&W F100-229 engines for flight-testing scheduled to begin in May.
The nozzles will be fitted to the former F-15B short take-off and landing/manoeuvre technology demonstrator under the advanced control technology for integrated vehicles (ACTIVE) programme run by NASA, the US Air Force, MDC and P&W. The year-long effort will explore the benefits of thrust vectoring for cruise optimisation, says P&W PYBBN programme manager Roger Bursey.
The ACTIVE project is a follow-on to the 135h multi-axis thrust-vectoring (MATV) flight-test programme, which was completed in March 1994 using a Lockheed F-16 temporarily equipped with a General Electric axisymmetric-vectoring engine nozzle. The P&W nozzles will remain on the ACTIVE F-15 following completion of the planned flight-tests, Bursey says.
P&W says that the fail-safe, dual-redundant, actuation system used on the nozzle will allow unrestricted flight-testing. The F-16 flight envelope was limited for MATV testing. P&W completed 48h of nozzle ground-testing in December, which included 12h in afterburner and more than 50,000 vectoring cycles. Vectoring was accomplished at up to 120¡/s at maximum power, the company says.
The NF-16D variable stability in-flight simulator test aircraft (VISTA), used for the MATV tests, was delivered to the USAF in January, to replace a variable-stability Lockheed NT-33A. A thrust-vectoring nozzle is to be permanently installed on the GE F110-powered aircraft under a funded upgrade programme which includes a helmet-mounted display and programmable front-cockpit sidestick.
The USAF's Lockheed F-22 will enter service with thrust-vectoring nozzles fitted as standard.
Source: Flight International
