The Federal Aviation Administration is once again looking into a close call at a major U.S. airport, after two passenger jets narrowly avoided a mid-air collision as they attempted to land in Phoenix.

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 FAA said it is investigating after a Delta Air Lines flight and United Airlines flight experienced 'a loss of required separation' while heading inbound to Phoenix Sky Harbor International Airport.

A Delta Air Lines plane and a United Airlines aircraft raised alarms when they flew too close to each other while flying into Phoenix on Saturday. The Federal Aviation Administration is investigating the “loss of required separation” incident.

The FAA has launched an investigation into a loss of separation between two commercial flights in Phoenix Saturday.

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.

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