NASA’s X-59 quiet supersonic research aircraft took another successful step toward flight with the conclusion of a series of engine performance tests.
In preparation for the X-59’s planned first flight this year, NASA and Lockheed Martin successfully completed the aircraft’s engine run tests in January. The engine, a modified F414-GE-100 that powers the aircraft’s flight and integrated subsystems, performed to expectations during three increasingly complicated tests that ran from October through January at contractor Lockheed Martin’s Skunk Works facility in Palmdale, California.
“We have successfully progressed through our engine ground tests as we planned,” said Raymond Castner, X-59 propulsion lead at NASA’s Glenn Research Center in Cleveland. “We had no major showstoppers. We were getting smooth and steady airflow as predicted from wind tunnel testing. We didn’t have any structural or excessive vibration issues. And parts of the engine and aircraft that needed cooling were getting it.”
The tests began with seeing how the aircraft’s hydraulics, electrical, and environmental control systems performed when the engine was powered up but idling. The team then performed throttle checks, bringing the aircraft up to full power and firing its afterburner – an engine component that generates additional thrust – to maximum.
Credit: NASA/Lillianne Hammel
A third test, throttle snaps, involved moving the throttle swiftly back and forth to validate that the engine responds instantly. The engine produces as much as 22,000 pounds of thrust to achieve a desired cruising speed of Mach 1.4 (925 miles per hour) at an altitude of approximately 55,000 feet.
The X-59’s engine, similar to those aboard the U.S. Navy’s F-18 Super Hornet, is mounted on top of the aircraft to reduce the level of noise reaching the ground. Many features of the X-59, including its 38-foot-long nose, are designed to lower the noise of a sonic boom to that of a mere “thump,” similar to the sound of a car door slamming nearby.
Next steps before first flight will include evaluating the X-59 for potential electromagnetic interference effects, as well as “aluminum bird” testing, during which data will be fed to the aircraft under both normal and failure conditions. A series of taxi tests and other preparations will also take place before the first flight.
The X-59 is the centerpiece of NASA’s Quesst mission, which seeks to solve one of the major barriers to commercial supersonic flight over land by making sonic booms quieter.
