About 25% Starlink odds, weighted to recent UA503 flights. A firm answer comes about 2 days before departure, once the aircraft is assigned.
Based on 80 recent flights; Starlink found in 2 of 8 Wi-Fi checks since Jan 18, 2026 (last N61898, Oct 7, 2026).
Aircraft seen on UA503: Boeing 737-900ER, Boeing 737-700, Airbus A321neo, Airbus A319.