At approximately 12:15 p.m. local time, the actor was piloting his private plane and coming in for a landing at John Wayne Airport near Orange County.
"Air traffic controllers cleared the pilot of a single-engine Aviat Husky to land on Runway 20L at John Wayne Airport Monday afternoon," the FAA said in a statement to E! News. "The pilot correctly read back the clearance. The pilot then landed on a taxiway that runs parallel to the runway, overflying a Boeing 737 that was holding short of the runway. The FAA is investigating this incident."
According to reports, Harrison was captured on air traffic control recordings asking, "Was that airliner meant to be underneath me."
Landing on a taxiway is a violation of Federal Aviation Administration safety rules. A spokeperson for American Airlines said, "We are aware of the incident, and have reported it to the NTSB and FAA."
The Star Wars and Indiana Jones star is an experienced pilot with decades of flying experience.
Back in March 2015, however, Harrison sustained moderate injuries after a small plane he was piloting crashed at a golf course in Venice, Calif. The single-engine plane crashed on the grounds of the Penmar Golf Course, which is near Santa Monica Airport.
Harrison was able to recover from his injuries.
"I'm doing great," he said on Good Morning America before ringing in 2016. "I'm back playing tennis, riding my bikes and having a good time."
—Reporting by Holly Passalaqua