The two flights, United Airlines Flight 1724 and Delta Air Lines Flight 1070 came too close to each other while arriving at the airport.

The pilots talked to air traffic controllers who appear to have directed the planes to "resequence," and flight data appears to show both making a circle before landing safely.

The Federal Aviation Administration is investigating a narrowly missed midair collision between a United flight and a Delta flight at Phoenix Sky Harbor International Airport on Saturday, the agency said.