NASA Tests X-59, a Supersonic Aircraft with a Quieter Boom

NASA's X-59 aircraft during a test flight over the Mojave Desert, California. The X-59 is being developed to produce a quieter sonic boom when flying supersonic. (Photo: NASA/Carla Thomas via Ars Technica.)

NASA has begun testing the X-59 Quesst, a supersonic experimental aircraft designed not to produce a loud sonic boom. A sonic boom is a loud explosion sound that appears when an aircraft travels faster than the speed of sound.

Citing a report by Ars Technica, Tuesday, June 30, the X-59 made by Lockheed Martin first flew at the end of last year and is now undergoing supersonic testing. NASA plans to take this plane around the United States so that residents can assess the sound of the resulting boom directly.

X-59 Quesst is an abbreviation for Quiet SuperSonic Technology. This aircraft was developed to prove that supersonic flight over land can be made more friendly for residents below.

This issue is important because the United States has banned commercial supersonic flights over land since 1973. The ban came after military test flights in the 1960s sparked noise complaints in Oklahoma City, Chicago, and St. Louis.

NASA hopes that data from the X-59 will help regulators draft new rules. If successful, future supersonic aircraft can fly over land without disturbing people on the ground.

The key to the X-59 is in its shape. The nose of the plane is made very long and tapered, almost a third of the length of the fuselage which is close to 100 feet. This shape is designed to break the shock wave when the plane travels faster than the speed of sound.

Peter Coen, NASA's Quesst mission integration manager, said every part of the X-59, from the nose, the position of the engines above the fuselage, to the shape of the wings, was made to control the strength of the shock wave.

In a typical supersonic plane, shock waves from the nose, canopy, engines, wings, and tail pile up and then descend to the ground as a sonic boom. In the X-59, the waves are made more spread out so that they reach the ground as a softer thud or hiss.

For comparison, the Concorde sonic boom reaches about 105 PldB, a unit of noise level that humans feel. NASA's target for the X-59 is around 75 PldB.

The extreme design has consequences. The X-59 pilot has no front window. Instead, the pilot wears an eXternal Vision System or XVS that displays a front view from two high-resolution cameras to a 4K monitor in the cockpit.

Jim "Clue" Less, a test pilot and NASA aerospace engineer, said the system felt routine after long practice. Less practiced more than 300 hours in the simulator, while lead test pilot David Nils Larson more than 500 hours. Both also practiced about 1,000 simulator landings.

According to Ars Technica, the X-59 is nicknamed "frankenjet" because it uses components from many other aircraft. Its landing gear comes from the F-16, the gas lever from the F-18 Super Hornet, the control stick from the F-117 Nighthawk, and the cockpit is based on the T-38 trainer jet.

The engine uses the F414-GE-100, a special variant of the F-18 Super Hornet's turbofan engine, with 22,000 pounds of thrust. Its avionics system uses the Rockwell Collins Pro Line Fusion, which is commonly used on the Beechcraft King Air, so that this aircraft can later operate more safely with other civilian aircraft.

The first flight test of the X-59 began on October 28, 2025. By June 2026, Less had flown the plane 10 times, while Larson had nine.

The most serious disruption occurred on the second flight, March 20. About five minutes after takeoff, warning lights came on and indicated a possible air leak that could have triggered a fire. The automatic cabin pressure system shut down. Less immediately returned and landed safely. An investigation later revealed that the alarm was false due to the incorrect installation of an indicator instrument.

On June 5, 2026, the X-59 broke the speed of sound for the first time. In an 81-minute flight, the plane reached Mach 1.1 or about 713 miles per hour at an altitude of 43,400 feet.

NASA continued the second supersonic test on June 12. This time the X-59 reached Mach 1.4 or about 924 miles per hour at an altitude of 55,000 feet. The speed and altitude will be a reference for measuring the sonic boom in the next test.

The next phase is carried out in a restricted airspace near Edwards Air Force Base, California. NASA will measure shock waves using instruments on the nose of the aircraft, microphones on the motor glider at an altitude of about 10,000 feet, and acoustic recorders on the ground.

The most important phase will come when the X-59 is flown over a number of communities in the United States. Residents will be asked to assess the sound they hear during about a month of testing in each region.

The tested booms will vary, from around 70 to 90 PldB. Coen said some people may not hear anything at low levels. However, at higher levels, the sound can be annoying.

Data from microphones, flights, and citizen responses will be submitted to the Federal Aviation Administration or FAA and the International Civil Aviation Organization or ICAO. From this data, regulators can draft new standards for supersonic flights over land.

If X-59 succeeds, its test data could pave the way for the return of commercial supersonic flights over land with lower noise levels.