PRATT &WHITNEY plans to demonstrate pro-active diagnostic technologies planned for its Joint Strike Fighter (JSF) engine. "Prognostics" will be able to detect impending failures, increasing powerplant reliability in the single-engined fighter, the company says.
"Single-engine safety is paramount in the JSF," says Frank Gillette, P&W director of advanced military-engine programmes. The goal must be to reduce the loss rate caused by engine failure to below the 1/100,000h level achieved with the Lockheed Martin F-16, he says.
New engine sensor technologies are being explored, including:
-acoustic detection of foreign-object damage;
-eddy-current vibration monitoring to detect fan-flutter;
-electrostatic monitoring of the engine exhaust to detect and characterise any metal content;
-continuous monitoring of oil condition and coking.
Other engine features will include component health and life tracking, and fault detection and isolation to individual line-replaceable units mounted on the engine. P&W's JSF engine is a derivative of the F119 developed to power the Lockheed Martin/Boeing F-22. Changes include a scaled-up integrally bladed-rotor fan, additional low-pressure-turbine stage and increased systems redundancy.
P&W JSF programme manager Bob Cea says that two F100 fighter engines are due to be ground-tested in 1998-9, to demonstrate the sensor technologies planned for the JSFF119. "We will seed failures into the engines and use the prognostics and diagnostics to register the events and see what happens," he says.
The prognostic and heath-monitoring technologies will be further evaluated in a "virtual testbench" before installation in two "slave" F119s modified to represent the JSF engine, Cea says. These will be ground-tested in 1999, before P&W submits its proposal for the JSF development programme, planned to begin in 2001.
Source: Flight International
