A United Airlines flight came within a few hundred feet of a military helicopter near John Wayne Airport in Southern California earlier this week, triggering an alarm that directed the airline pilots to alter their course.

The Federal Aviation Administration (FAA) announced on Friday that it is investigating the incident that occurred around 8:40 PM on Tuesday. A military Black Hawk helicopter returning from a training session crossed into the path of the passenger plane, which was carrying 162 passengers and 6 crew members. The pilots of United Flight 589 halted their descent and leveled off to avoid a collision.

This alarming close call comes just over a year after an American Airlines jet collided with an Army Black Hawk helicopter near Washington, D.C., resulting in the deaths of 67 people — the deadliest aviation accident on U.S. soil in more than two decades. This crash has heightened scrutiny surrounding flight paths and safety regulations intended to prevent near misses between various aircraft.

In response to the previous crash, the FAA updated its policies earlier this month, demanding that air traffic controllers actively utilize radar to guide helicopters and planes around airports nationwide, instead of relying solely on pilots to see and navigate around each other. Prior to the crash, controllers had asked helicopter pilots if they had visual contact with the approaching aircraft and allowed them to proceed without altitude restriction.

The FAA has indicated that it will continue to examine whether the new safety protocols were effectively implemented during this latest incident.

In a brief statement following the occurrence, United Airlines confirmed the details, stating, “During the final approach to John Wayne Airport, pilots on United flight 589 were advised by air traffic control to watch for a military helicopter flying near the airport. They saw the helicopter and received a traffic alert, which they responded to by leveling the aircraft.”

According to data from FlightRadar24, the United plane came within 525 feet vertically and 1,422 feet laterally of the helicopter at their closest point before the crew responded to the anti-collision alarm and leveled off.

Audio from the traffic control tower at John Wayne Airport revealed that the controller inquired whether the United pilot had received any advisories regarding the helicopter or altitude restrictions. The pilot confirmed receiving a “resolution advisory,” indicating a serious collision avoidance alert issued by the aircraft’s systems. The controller expressed concern over the close encounter, stating, “We’re going to be addressing that, because that was not good.”

A spokesperson for the California National Guard confirmed that the helicopter was conducting training and was returning to its base, maintaining communication with air traffic control throughout the flight.

The FAA has yet to announce any temporary restrictions on flight paths or training routes following the Tuesday incident. An airport spokesperson indicated that, due to the incident's occurrence in the air rather than at the airport itself, no additional information could be provided.

This close call comes just days after a separate incident where an Air Canada jet collided with a fire truck on a runway at New York’s LaGuardia Airport, raising further alarms about the safety of aircraft operations in proximity to one another.