About 37% Starlink odds, weighted to recent UA1991 flights. A firm answer comes about 2 days before departure, once the aircraft is assigned.
Based on 102 recent flights; Starlink found in 2 of 17 Wi-Fi checks since Jan 15, 2026 (last N28457, Oct 19, 2026).
Aircraft seen on UA1991: Boeing 737-900ER, Airbus A319, Airbus A320.