The FAA says registration for the Republican presidential front-runner's Cessna Citation corporate jet expired January 31. Based on sightings from CNN's political team embedded with the Trump campaign, the Trump plane appears to have violated the FAA regulations by flying it to campaign events after its registration had expired.
The FAA requires all aircraft be registered before they're flown.
"The aircraft registration of N725DT expired on January 31, 2016 and has not been renewed," FAA spokeswoman Laura Brown said in an email to CNN.
The registration expiration was first reported by the New York Times on Tuesday.
Flying an unregistered aircraft can result in criminal penalties including a $250,000 fine and up to three years behind bars. It could also result in a $27,500 civil penalty.
Donald Trump's campaign did not respond to questions asking how many times Trump has flown on the plane since January 31 or why the registration was allowed to expire.
"The standard renewal process is just about complete," campaign spokeswoman Hope Hicks said.
Trump's corporate jet is designed to seat 12. It's painted white and has a gold Trump family crest stamped near the passenger door of the plane.
The FAA has not decided what action if any it will take against the presidential candidate.
In order to register an aircraft a $5 fee and specific paperwork are required.
FAA records show Trump's larger aircraft, a Boeing 757, is in good standing. The 757's registration does not expire until March 31, 2018.
Trump also flies a Sikorsky helicopter emblazoned with his name.