The engine has exceeded 10 million engine flight hours overall, Boeing said, and passed 2.5 million flight hours while supporting military and humanitarian missions.
"This milestone is a testament to the reliability of the F117 engine," said Bev Deachin, vice president, Military Programs and Customer Support, Pratt and Whitney.
"The exceptional performance of our engines -- in some of the harshest conditions -- has helped the C-17 Globemaster III save countless lives in military, humanitarian and disaster relief missions around the world."
The F117-PW-100 entered service in 1993 and has accumulated more than 6 million flight hours in support of worldwide air mobility missions since 2006, the company said. The 4 million flight-hour milestone took 13 years to reach. The more rapid achievement of the remaining miles underlines the C-17's increased operational use.
"Through Pratt and Whitney's ongoing investment in product improvements and industry partnerships the engine continuously surpasses established goals of time on-wing and support turnaround time," said Deachin.
"The F117 engine can remain on-wing for up to eight years between servicing visits, which lowers maintenance costs and provides outstanding mission readiness for C-17 customers."
Pratt and Whitney has delivered more than 1,100 F117 engines to customers, including the U.S. Air Force and the air forces of Britain, Canada Qatar, the United Arab Emirates and others.