UA2840 from Hagåtña to San Francisco, tracked live

UA2840 distance and great-circle path

UA2840 covers 9,341 km, or 5,804 miles. That makes it an ultra-long-haul flight, near the limit of what most twinjets can fly non-stop. Of the 315 routes we track, it ranks 83 by distance.

Hagåtña to San Francisco crosses the international date line. The 9,341 km track runs north-east, and the calendar date at the gate in San Francisco will not be the one the cabin expects. It links GU with United States.

Our guide explains how the GUM-SFO route appears on a tracker map.

Can the Boeing 737-900ER comfortably fly UA2840?

Yes. The route uses roughly 171% of what a Boeing 737-900ER can fly. On a windy day the airline may carry less cargo to save fuel. Flights this close to the limit are the ones that sometimes make a fuel stop. The full numbers are on our aircraft page for the Boeing 737-900ER.

What to know about UA2840

• Time change: you land 17 hours behind the time you left. That is enough to cause jet lag. Here is how pilots handle it.
• Crosses the date line: the calendar date changes while you are in the air.

What flying GUM to SFO takes

It is an ultra-long-haul sector, near the limit of what most twinjets can fly non-stop. United Airlines needs a long-range widebody such as an A350, 787 or 777: few types can fly this far with a commercial payload, and headwinds can force a technical stop on the worst days. Eastbound, the jet stream is usually a tailwind, so the return leg against it tends to be the longer of the two. In daylight the sun sits on the right (south-facing) side of the cabin for most of the crossing.

How we verified this

The origin and destination on this page are the ones we verified for callsign UAL2840 through adsbdb, not a schedule copied from elsewhere. We have logged it airborne on 15 days between 2026-09-20 and 2026-10-06. Timings are observations, not an official operational status: always confirm with the airline before travelling.

This page was published from our own tracking record rather than a third-party schedule feed, so it grows as we see the flight again. The seven-day log below is the raw version of the same evidence.

Our database contains 8 observations of UA2840 across 8 UTC dates in this window, most recently 2026-10-06. Those records contain 6 distinct transponder addresses. The most frequently resolved route was GUM-SFO (7 records).

The median recorded visibility was 1389 minutes. That is time inside receiver coverage, not airborne duration or an on-time-performance measurement.