Two Southwest Airlines Boeing 737s came within seconds of colliding over Nashville International Airport in April 2026 after a controller directed one jet straight into the path of another, triggering emergency alerts in both cockpits and forcing crews to wrench their aircraft apart in midair. The Federal Aviation Administration has opened a formal investigation into the incident, which involved Southwest Flight 507 and Southwest Flight 1152 during parallel-runway operations at one of the Southeast’s busiest airports.
No one was injured. But the encounter, classified by the FAA as a loss of separation, is the latest in a string of alarming near misses at U.S. airports that have put controller workload and procedural safeguards under intense scrutiny.
How the conflict unfolded
The sequence began when one of the two Southwest flights executed a go-around, a standard maneuver in which a pilot aborts a landing attempt and climbs away from the runway. Go-arounds happen thousands of times a year across the national airspace system and are considered routine.
What made this one dangerous was the heading assignment that followed. According to reporting by the Associated Press, the climbing aircraft was directed onto a course that crossed into the flight path of the second jet, which was on final approach to a parallel runway. Within moments, both cockpit crews received Resolution Advisories from their onboard Traffic Collision Avoidance Systems, known as TCAS, and immediately maneuvered to increase separation.
TCAS is the last automated safety net in commercial aviation. When it issues a Resolution Advisory, pilots are trained to follow its climb-or-descend command instantly, overriding any instruction from air traffic control. The system typically fires when aircraft are projected to close within roughly 15 to 35 seconds of each other, meaning the margin between a safe outcome and a catastrophe had already narrowed sharply before the technology intervened.
What the FAA has confirmed
The FAA has acknowledged the investigation and classified the event as a loss of separation, the agency’s formal designation for any incident in which the required distance between aircraft is violated. Air traffic control audio from the Nashville tower exists and is part of the review.
Southwest Airlines confirmed the incident in a statement, praising the quick response of its flight crews and saying the carrier is cooperating fully with federal investigators. The airline did not disclose how many passengers were aboard the two flights.
The Washington Post reported that the controller error occurred after the go-around, consistent with the AP’s account. Both outlets identified the same flight numbers and confirmed the activation of collision-avoidance systems aboard both aircraft.
Key questions still unanswered
No dedicated FAA incident report for this event has appeared on the agency’s public data portal as of early May 2026. That means several critical details remain unconfirmed:
- Closest point of approach. The exact vertical and lateral separation when the two 737s were nearest to each other has not been officially released. Some early reports have cited approximate figures, but until the FAA publishes measurements drawn from radar tracks and flight data recorders, those numbers should be treated as preliminary.
- Root cause. It is not yet clear whether the misrouting resulted from a single controller’s error, a miscommunication between positions in the tower cab, or a gap in Nashville’s procedures for handling go-arounds during parallel approaches.
- Controller status. The FAA has not disclosed whether the controller or controllers involved have been placed on administrative leave or reassigned, a step that is standard practice during serious separation investigations.
- NTSB referral. The agency has not indicated whether the incident will be referred to the National Transportation Safety Board for an independent review, a decision that typically hinges on the severity classification the FAA assigns after its initial assessment.
The National Air Traffic Controllers Association, the union representing most FAA controllers, has not issued a public statement about the Nashville incident.
Nashville’s parallel-runway challenge
Nashville International Airport operates multiple parallel runways that handle a growing volume of commercial traffic. The airport has seen passenger numbers surge in recent years as the city’s population and tourism economy have expanded, putting additional pressure on controllers managing tightly spaced arrival and departure flows.
Parallel-runway operations are common at mid-size and large U.S. airports, but they demand precise coordination, especially when a go-around on one runway sends a climbing aircraft across the approach path of traffic inbound to the adjacent runway. Procedures exist to prevent exactly the kind of conflict that occurred here, and investigators will be examining whether those procedures were followed as written or whether they need to be revised.
The incident also lands against a backdrop of persistent concerns about FAA controller staffing. A 2023 Department of Transportation Inspector General report found that the agency was short roughly 3,000 controllers nationwide, and the FAA has acknowledged that many facilities, particularly at mid-size towers with rising traffic, are operating below optimal levels. Whether Nashville’s tower was adequately staffed at the time of the near miss is among the questions the investigation is expected to address.
A pattern of close calls
The Nashville incident is not an isolated event. Over the past three years, a series of high-profile near misses at U.S. airports has drawn congressional attention and prompted the FAA to launch a broader safety review. Notable incidents include a near collision between a FedEx cargo plane and a Southwest 737 at Austin-Bergstrom International Airport in February 2023, and multiple runway incursions at New York’s John F. Kennedy International Airport the same year.
In each case, onboard safety systems or alert crew action prevented contact. But the frequency of these events has raised pointed questions about whether the national airspace system’s safety margins are thinning as traffic volumes recover from the pandemic while controller ranks remain depleted.
What kept these planes apart
For the passengers aboard Southwest flights 507 and 1152, the outcome hinged on a piece of technology that has been mandatory on commercial aircraft since the early 1990s. TCAS operates independently of ground-based radar and controller instructions, using transponder signals to track nearby aircraft and calculate whether their paths will converge. When it determines a collision is possible, it issues coordinated commands to the involved aircraft: one crew is told to climb, the other to descend.
The system performed as designed over Nashville. Both crews followed their TCAS commands, and the aircraft separated safely. But TCAS is explicitly built as a last resort, not a substitute for proper air traffic control. Every time it fires in a situation like this, it signals that the layers of human oversight meant to prevent the conflict in the first place have already failed.
The FAA’s investigation will need to determine exactly where those layers broke down, whether the fix is procedural, structural, or both, and whether Nashville’s tower needs changes before a similar scenario plays out with a different outcome. Until the agency publishes its findings, the most reliable source for updates is the FAA’s accident and incident data portal, where investigative summaries are posted as they become available.
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*This article was researched with the help of AI, with human editors creating the final content.
