Supersonic X-59 jet hits Mach 1.4 speed at 55,000 feet in milestone flight test

For nearly 11 years, test pilot Mike Lippert pushed high-performance aircraft to maximum performance. But one ultimate career milestone kept eluding him. He had never flown an X-plane. And he ultimately got an opportunity to fly one on October 21.

Soaring high above California’s Mojave Desert, Lippert finally realized his lifelong ambition by taking control of NASA’s X-59 quiet supersonic research aircraft for the first time.

The flight is a key triumph for both the pilot and NASA’s mission to reshape the future of commercial air travel.

A dream decades in the making

Lippert launched from NASA’s Armstrong Flight Research Center in Edwards, California. And stayed airborne for exactly one hour.

During the flight, the sleek research jet reached a top speed of Mach 1.4 while cruising at 55,000 feet.

“After completing our high-altitude test points, there was a brief period where we descended and decelerated, where I was able to look outside and recognize that I was flying supersonic in an X-plane over the high deserts of the Mojave,” Lippert recalled. “It was a special moment for sure.”

While the X-59 has taken to the skies before, getting Lippert ready for his maiden flight required months of preparation.

He didn’t do it alone. Working closely alongside fellow NASA test pilots Nils Larson and Jim “Clue” Less, Lippert spent countless hours in ground simulators mapping out every potential variable. In August, he performed his first engine run inside the cockpit, honing communication routines with the mission control team.

That meticulous ground prep paid off. Lippert smoothly executed complex maneuvers to test the jet’s handling and system integrity.

For Lippert, the achievement was as emotional as it was technical.

“This flight was very special to me,” Lippert said. “For as long as I can remember, I’ve dreamt of doing exactly what I got to do today, testing a truly unique aircraft and working with the exceptional people on this test team.”

NASA’s Quesst mission

The aircraft made a triumphant return to the skies following a routine maintenance check and a comprehensive system review. This ground inspection followed its most intensive operational stretch yet, during which the crew completed six flights in just three days. Building on that momentum, engineers approved the jet for its next major milestone.

The X-59 has a unique, needle-like nose designed to disperse shockwaves, and cuts the need for a forward windshield. Pilots like Lippert navigate using an External Vision System (XVS) that streams a virtual 4K forward view to an internal cockpit monitor.

Interestingly, the aircraft was built from repurposed parts from established fighter jets, such as a T-38 canopy and ejection seat, along with F-16 landing gear. These measures helped to reduce development time and costs. A single General Electric F414 engine powers the experimental jet, producing 22,000 pounds of thrust with afterburners to drive its supersonic research flights.

The primary objective of NASA’s Quesst mission involves conducting test flights with the X-59 over various US communities to measure public reaction to quiet supersonic sound. Researchers plan to share these acoustic findings with aviation regulators to establish data-driven noise standards. This evidence could eventually persuade authorities to repeal the decades-long ban on commercial overland supersonic travel.