United 737 and US Army Black Hawk Involved in Santa Ana Close Call On the evening of Tuesday, March 24, a US Army UH-60M Black Hawk helicopter crossed in front of a United Airlines 737-800 aircraft approaching Santa Ana John Wayne Airport (SNA) in California. The incident prompted a Traffic Collision Avoidance System (TCAS) Resolution Advisory for the United crew, indicating a potential conflict between the two aircraft. The closest point of approach occurred at 03:40:35 UTC, with the helicopter at 1,425 feet altitude and the 737 descending through 2,000 feet. The vertical separation between the aircraft was 525 feet, while lateral distance measured 1,422 feet. United flight UA589, operating from San Francisco to Santa Ana, received the TCAS advisory as the helicopter intruded into its flight path. The crew immediately arrested the aircraft’s descent to comply with the advisory and continued the approach, ultimately landing safely approximately three minutes after the closest point. The incident highlights the risks of close proximity between fixed-wing aircraft and helicopters during airport operations. The Federal Aviation Administration (FAA) announced an investigation into the incident on March 26, focusing on whether the agency’s new rule prohibiting visual separation between helicopters and fixed-wing aircraft near major airports was applied. The rule, effective recently, mandates radar-based separation instead of relying on visual confirmation to prevent conflicts. The FAA’s probe aims to assess compliance with the regulation and determine if procedural lapses contributed to the near-miss. Data from the incident, including TCAS status codes, is available for download in CSV format.#federal_aviation_administration #united_airlines #us_army_black_hawk #santa_ana_john_wayne_airport #california_air_national_guard