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 two flights, United Airlines Flight 1724 and Delta Air Lines Flight 1070 came too close to each other while arriving at the airport.
A United Airlines 737 MAX 9 jet hit a coyote during takeoff on Sunday. It wasn't the only flight incident involving United over the weekend.
FAA officials say the two planes "landed safely after experiencing a loss of required separation" as they were headed to Sky Harbor.
The Federal Aviation Administration (FAA) said it is investigating a recent near-midair collision of flights that were approaching Phoenix Sky Harbor International Airport. A Delta Air Lines
The FAA has launched an investigation into a loss of separation between two commercial flights in Phoenix Saturday.
Multiple airlines are being affected by the delays including DELTA, American Airlines, Southwest, and a few others.
CNN has reached out to Phoenix Sky Harbor International Airport, Delta Air Lines and United Airlines for comment. The incident in Phoenix follows a rise in recent years of “runway incursions ...