{"id":352596,"date":"2026-01-21T05:11:25","date_gmt":"2026-01-20T19:11:25","guid":{"rendered":"https:\/\/www.nasa.gov\/?p=944186"},"modified":"2026-01-21T05:11:25","modified_gmt":"2026-01-20T19:11:25","slug":"nasa-chase-aircraft-ensures-x-59s-safety-in-flight","status":"publish","type":"post","link":"https:\/\/www.vibewire.com.au\/?p=352596","title":{"rendered":"NASA\u00a0Chase Aircraft Ensures\u00a0X-59\u2019s\u00a0Safety\u00a0in Flight\u00a0"},"content":{"rendered":"
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5 min read<\/p>\n

Preparations for Next Moonwalk Simulations Underway (and Underwater)<\/h1>\n<\/div>\n<\/div>\n<\/div>\n
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\"NASA\u2019s<\/a><\/figure>
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NASA\u2019s X-59 quiet supersonic research aircraft flies above Palmdale and Edwards, California, during its first flight Tuesday, Oct. 28, 2025, accompanied by a NASA F-15 research aircraft serving as chase.<\/div>\n
NASA\/Jim Ross<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\n

As NASA\u2019s X-59 quiet supersonic research aircraft<\/a> continues a series of flight tests over the California high desert in 2026, its pilot will be flying with a buddy closely looking out for his safety. <\/p>\n

That colleague will be another test pilot in a separate chase aircraft. His job as chase pilot: keep a careful watch on things as he tracks the X-59 through the sky, providing an extra set of eyes to help ensure the flight tests are as safe as possible. <\/p>\n

Having a chase pilot watch to make sure operations are going smoothly is an essential task when an experimental aircraft is exercising its capabilities for the first time. The chase pilot also takes on tasks like monitoring local weather and supplementing communications between the X-59 and air traffic control. <\/p>\n

\u201cAll this helps reduce the test pilot\u2019s workload so he can concentrate on the actual test mission,\u201d said Jim \u201cClue\u201d Less<\/a>, a NASA research pilot since 2010 and 21-year veteran U.S. Air Force flyer. <\/p>\n

Less served as chase pilot in a NASA F\/A-18 research jet when NASA test pilot Nils Larson<\/a> made the X-59\u2019s first flight on Oct. 28<\/a>. Going forward, Less and Larson will take turns flying as X-59 test pilot or chase pilot. <\/p>\n

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\"Two<\/a><\/figure>
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NASA pilots Jim \u201cClue\u201d Less (left) and Nils Larson celebrate the X-59\u2019s first flight on Oct. 28, 2025. Less flew an F-18 chase aircraft while Larson flew the X-59.<\/div>\n
NASA\/Genaro Vavuris<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\n

Staying Close<\/h3>\n

So how close does a chase aircraft fly to the X-59? <\/p>\n

\u201cWe fly as close as we need to,\u201d Less said. \u201cBut no closer than we need to.\u201d <\/p>\n

The distance depends on where the chase aircraft needs to be to best ensure the success of the test flight. Chase pilots, however, never get so close as to jeopardize safety. <\/p>\n

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We fly as close as we need to, but no closer than we need to.<\/span><\/h2>\n<\/p><\/div>\n
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\"Jim<\/figure>\n<\/div>\n
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Jim "clue" LESS<\/p>\n

NASA Test Pilot<\/p>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/div>\n

For example, during the X-59\u2019s first flight the chase aircraft moved to within a wingspan of the experimental aircraft. At that proximity, the airspeed and altitude indicators inside both aircraft could be compared, allowing the X-59 team to calibrate their instruments. <\/p>\n

Generally, the chase aircraft will remain about 500 and 1,000 feet away\u2014or about 5-10 times the length of the X-59 itself\u2014as the two aircraft cruise together. <\/p>\n

\u201cOf course, the chase pilot can move in closer if I need to look over something on the aircraft,\u201d Less said. \u201cWe would come in as close as needed, but for the most part the goal is to stay out of the way.\u201d <\/p>\n

Airborne Photo Op<\/h3>\n
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\"The<\/a><\/figure>
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In a view captured from a NASA F-18 chase aircraft, the X-59 quiet supersonic research aircraft lifts off for its first flight Oct. 28, 2025, from U.S. Air Force Plant 42 in Palmdale, California.<\/div>\n
NASA\/Lori Losey<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\n

The up-close-and-personal vantage point of the chase aircraft also affords the opportunity to capture photos and video of the test aircraft.  <\/p>\n

For the initial X-59 flight, a NASA photographer\u2014fully trained and certified to fly in a high-performance jet\u2014sat in the chase aircraft\u2019s rear seat to record images and transmit high-definition video down to the ground. <\/p>\n

\u201cWe really have the best views,\u201d Less said. \u201cThe top focus of the test team always is a safe flight and landing. But if we get some great shots in the process, it\u2019s an added bonus.\u201d <\/p>\n

Chase aircraft can also carry sensors that gather data during the flight that would be impossible to obtain from the ground. In a future phase of X-59 flights, the chase aircraft will carry a probe to measure the X-59\u2019s supersonic shock waves<\/a> and help validate that the airplane is producing a quieter sonic \u201cthump,\u201d rather than a loud sonic boom to people on the ground. <\/p>\n

The instrumentation was successfully tested<\/a> using a pair of NASA F-15 research jets earlier this year. <\/p>\n

As part of NASA\u2019s Quesst mission, the data could help open the way for commercial faster-than-sound air travel over land. <\/p>\n

Choice of Chase Aircraft<\/h3>\n
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A NASA F-15 aircraft sits 20 feet off the left side of the X-59 aircraft, with a white hangar and hills in the background, during electromagnetic interference testing.<\/div>\n
NASA\/Carla Thomas<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\n

Chase aircraft have served as a staple of civilian and military flight tests for decades, with NASA and its predecessor\u2014the National Advisory Committee for Aeronautics\u2014employing aircraft of all types for the job. <\/p>\n

Today, at NASA\u2019s Armstrong Flight Research Center<\/a> in Edwards, California, two different types of research aircraft are available to serve as chase for X-59 flights: NASA-operated F\/A-18 Hornets<\/a> and F-15 Eagles<\/a>. <\/p>\n

While both types are qualified as chase aircraft for the X-59, each has characteristics that make them appropriate for certain tasks. <\/p>\n

The F\/A-18 is a little more agile flying at lower speeds. One of NASA\u2019s F\/A-18s has a two-seat cockpit, and the optical quality and field of view of its canopy makes it the preferred aircraft for Armstrong\u2019s in-flight photographers. <\/p>\n

At the same time, the F-15 is more capable of keeping pace with the X-59 during supersonic test flights and carries the instrumentation that will measure the X-59\u2019s shock waves. <\/p>\n

\u201cThe choice for which chase aircraft we will use for any given X-59 test flight could go either way depending on other mission needs and if any scheduled maintenance requires the airplane to be grounded for a while,\u201d Less said. <\/p>\n

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