Southwest Flight Medical Emergency Diverts Flight 512 Back to Honolulu

A passenger medical emergency forced Southwest Flight 512 to return to Honolulu on Tuesday night after departing for San Diego. The aircraft had left Hawaii around 9 p.m. when crew declared an emergency following an undisclosed medical issue aboard, according to reports from 10News and FOX 5 San Diego.

Southwest Airlines confirmed the return decision was governed by an FAA-designated demarcation point — an operational framework applied to Hawaii-mainland routes that determines whether a flight in crisis should turn back or press on to its destination. The protocol is standard for transpacific operations and is designed to ensure passengers receive the fastest possible medical intervention. A similar diversion occurred on Southwest Flight 139 from Maui to Las Vegas, where crews applied the same procedures to manage a mid-Pacific medical event.

Operational Impact

Flight 512 had been scheduled to arrive in San Diego just before 6 a.m. Wednesday. Following the diversion, Southwest rescheduled the departure for 9:25 p.m. Wednesday, with an expected San Diego arrival of 5:50 a.m. Thursday — a delay of roughly 24 hours for affected passengers.