UA3931 · UAL3931

UAL3931 over the last 30 days

As of 2026-10-09

UAL3931 is operated by United Airlines on the route Washington Dulles International Airport (IAD/KIAD) → San Francisco International Airport (SFO/KSFO). Most frequent aircraft type: BOEING 787-9 Dreamliner (B789).

Days with an observed flight (last 30 days)

3/30

Days of the week with an observed flight

Fri

Median departure deviation from the usual time on this route

+2 min

Departures within 15 minutes of the usual time

74 %

Departures measured

184

Our measurement against the usual departure time of the route, from our own observations over the last 28 days; the figures cover all flights of this airline on the route.

Aircraft types on this flight (last 30 days)

• BOEING 787-9 Dreamliner (B789) — Number of flights: 2
• BOEING 737 MAX 8 (B38M) — Number of flights: 1

Related flights on this route

• All flights KIAD – KSFO