The Federal Aviation Administration is investigating a near-miss between two commercial flights at Phoenix Sky Harbor International Airport on Saturday, involving a United Airlines flight from San Francisco and a Delta Air Lines flight from Detroit.

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 close call between the United and Delta flights at the Phoenix airport comes amid an increase in plane near-collisions.

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

SAN FRANCISCO — An earthquake registering a magnitude ... is responsible for some of the largest shakers in state history. FAA data analyzed by Newsday shows the number of bird strikes ...

FAA officials say the two planes "landed safely after experiencing a loss of required separation" as they were headed to Sky Harbor.

At the same time, a similar alert was set off on a United Flight 1724 from San Francisco, carrying 123 ... according to FlightRadar24. The FAA noted both planes landed safely "after experiencing ...

The FAA said it is investigating the incident ... The United flight was a Boeing 737-900 en route from San Francisco and carrying 123 passengers and six crew, the spokesperson 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.

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 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.