FAA investigates near-collision at Phoenix airport

The Federal Aviation Administration (FAA) is investigating a narrowly missed midair collision between two planes carrying hundreds of passengers at Phoenix airport over the weekend.

A United Airlines flight was less than a quarter mile (440m) from a Delta flight as the planes were trying to land at Phoenix Sky Harbor International Airport, preliminary flight data from Flightradar24 shows.

Both planes landed safely "after experiencing a loss of required separation when they were inbound", the FAA said in a statement.

An automated system - the Traffic Collision Avoidance System - was activated in both aircrafts to provide pilots with warning and instructions about potential collision.

Delta Flight, 1070, was carrying 245 passengers on an inbound flight from Detroit while the United Flight, 1724, was carrying 129 passengers on an inbound flight from San Francisco.

An air traffic controller cleared the United flight to land on Runway 7 and then directed the Delta flight to turn to land on Runway 8 when the incident occurred, according to audio obtained by CBS News, the BBC's US partner.

At that point, collision warning went off in the cockpit. "Descend, descend" can be heard in the background of the audio recording obtained by CBS.

"Both flight crews received onboard alerts that the other aircraft was nearby," the FAA said in its statement.

The planes were 425 ft (129m) apart vertically at one point. Less than a second later were less than a quarter of a mile apart horizontally, according to flight data from Flightradar24.

"As nothing is more important than safety, Delta flight crews extensively train to handle uncommon scenarios such as this and followed the resolution advisory as directed," Delta said in a statement obtained by the BBC.

The United flight received an automated flight deck warning to "change their altitude," United said in a statement.

"The pilots acted immediately and landed safely," it said. "We're working with the FAA on its investigation."

US airports have recorded a rise in "runway incursions" in recent years, according to FAA data. There were 1,757 such incidents in fiscal 2024.

The numbers are small compared to the more than 45,000 flights that take off across the US each day, experts say it's important to keep working to bring the incidents down.