BLOUNTVILLE - Tri-Cities Airport (TRI) confirmed Wednesday an American Airlines flight diverted to TRI and landed safely. Flight Number 4890 had departed Charlotte, N.C., and was headed to Lexington, Ky. The ERJ-145 aircraft landed at TRI at approximately 10:06 a.m. with 52 passengers and four crew on board. The subsequent flight from TRI to Lexington was canceled. “There is no impact to airport operations,” said an airport release, which did not disclose why the flight had to divert to TRI. The most common reasons a flight may be diverted are weather conditions, unruly passengers or a medical emergency, according to the Sheffield School of Aeronautics. There are also differences between a diversion and an emergency landing.