About 42% Starlink odds, weighted to recent UA391 flights. A firm answer comes about 2 days before departure, once the aircraft is assigned.
Based on 62 recent flights; Starlink found in 3 of 5 Wi-Fi checks since Apr 16, 2026 (last N14242, Sep 30, 2026).
Aircraft seen on UA391: Boeing 737-800, Boeing 737 MAX 8.