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 Federal Aviation Administration is investigating a runway incident involving a single-engine plane in North Texas.

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 planes, carrying more than 350 people, experienced "a loss of required separation" while preparing to land at the same Phoenix airport, the FAA said.

A United flight from San Francisco and a Delta flight from Detroit came within 425 feet of each other in the sky, according to flight radar data. NTSB guidelines say planes should always stay at least five miles apart.

The two planes experienced ‘a loss of required separation’ when they neared Phoenix Sky Harbor International Airport, the FAA said