Flight profile · United Airlines
UA648
Newark (EWR) to San Francisco (SFO) · scheduled 10:00 AM – 1:51 PM
How UA648 performs
956 operations, October 2023 – July 2026.
UA648 arrived on time 73.9% of the time, against 72.6% for all EWR → SFO flights, so this departure is 1.3 percentage points better than the route as a whole. Against United Airlines’ own flights on this route it is 1.8 points better.
Source: US DOT Bureau of Transportation Statistics · 956 operations, October 2023 – July 2026 · If UA648 is cancelled or significantly changed, DOT’s automatic refund rule may entitle you to your money back. The refund checker walks through eligibility.
Where UA648 is right now
A live reading, only if you ask for it. It is not part of the reliability record above.
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Against the rest of the route
| Flight or route | On time | Cancelled | Median delay | Severe | Flights |
|---|---|---|---|---|---|
| UA648 | 73.9% | 1.15% | -6 min | 11.3% | 956 |
| United Airlines on EWR → SFO | 72.1% | 2.19% | -5 min | 12.1% | 10,919 |
| All EWR → SFO flights | 72.6% | 2.10% | -6 min | 11.7% | 13,053 |
Source: FlyerIntel analysis of US DOT BTS data · October 2023 – July 2026
Why UA648 runs late
Where US DOT attributed the delay minutes on this flight.
crew, maintenance, boarding and fueling, all within the carrier’s control
the inbound aircraft was late, so this flight started late
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for UA648 on EWR → SFO. Only delays of 15 minutes or more are attributed.
Source: US DOT Bureau of Transportation Statistics · Data covering October 2023 – July 2026
Does a late aircraft delay this flight?
How often the plane that flies UA648 comes in late, and what that does to the departure.
The aircraft flying UA648 came in 15 or more minutes late on 20% of the departures where its previous flight is known. There are not enough departures in both groups to say how the flight left after a late one and after an on-time one.
Each departure is matched to the flight the same aircraft flew into EWR just before it, using the tail number in the DOT file, 494 of 945 departures in all. A departure is left out when that flight is unknown, was cancelled or diverted, or the aircraft had sat for more than 12 hours. A flight the airline cancelled never left and is not in the count, and one flown by a substitute aircraft is matched to the aircraft that flew it, not to the one first planned.
Against the network at the same turn length
| Share of departures | Inbound landed 15+ late |
|---|---|
| UA648 | 20% |
| Network, same turn | 23% |
The schedule leaves a long gap on the ground, which gives a late aircraft room to catch up before this flight pushes back.
The network row is every flight with a scheduled turn of 90 minutes to 3 hours. How often UA648’s aircraft landed 15 or more minutes late is about the same as the network’s. There are not enough departures in both groups to compare how it left.
More: Which Flight Numbers Pay for a Late Aircraft lists the flight numbers that pass a late aircraft on.
Source: US DOT Bureau of Transportation Statistics · Data covering October 2023 – July 2026
From pushback to gate
When it leaves EWR late, does that still matter by the time it reaches SFO?
UA648 pushes back an average of 23.1 minutes late and reaches the gate at SFO an average of 12.6 minutes late. The 10.5 minutes between those two figures are slack the published schedule already carries, which is why a late pushback on this flight does not reliably become a late arrival. It spends 26.5 minutes on the taxiways at EWR, 2.4 minutes longer than a typical EWR departure in the same hour.
On arrival at SFO, UA648 spends 8.2 min taxiing from touchdown to the gate — ground time a connecting passenger sits through before they can even leave the aircraft, on top of however late the flight itself ran. That is about what any arrival at SFO spends on the ground before reaching the gate.
Departure delay is averaged over every pushback and arrival delay over every completed arrival, so the two counts differ by the flights that never reached SFO. Taxi-out is gate to wheels up and sits inside the scheduled block rather than on top of it; the comparison is 23,655 departures from EWR scheduled in the clock hour UA648 most often leaves in. Taxi-in is landing to gate, compared against every arrival FlyerIntel has on file at SFO (436,060 flights), not just UA648’s own. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · October 2023 – July 2026
The hour it leaves EWR
Part of any flight’s record belongs to the clock rather than to the flight. UA648 has one departure time, so this is what that time is worth.
On-time arrival rate. 23,655 departures from EWR are scheduled in the 10 AM–11 AM hour over the period, against 387,621 across the whole day.
UA648 is scheduled out of EWR at 10:00 AM, in the 10 AM–11 AM bank. Departures from EWR in that hour arrive on time 82.3% of the time against 77.7% across the airport’s whole day — the slot alone is worth 4.6 points better before anything about this particular flight is considered.
The two airport figures cover every departure from EWR to every destination, so they describe the slot rather than this journey — the like-for-like comparison against the route is above. Hours are scheduled local, and a number whose schedule moved between banks inside the period has no single hour and is not described here at all. Why the hour matters.
Source: FlyerIntel analysis of US DOT BTS data · October 2023 – July 2026 · Hours below 120 departures are not scored.
By day of week
Does UA648 run worse on particular days?
Tuesday is historically the most reliable day and Friday the least, a gap of 11.2 percentage points.
Source: FlyerIntel analysis of US DOT BTS data · October 2023 – July 2026 · Days with fewer than 120 operations are not scored.
Other routes UA648 has flown
A flight number is a slot in a schedule, and carriers reassign it. These are the other city pairs this number served in the analysis period.
| Route | Operated | Flights | On time |
|---|---|---|---|
| STL→EWR St. Louis to Newark | June 27, 2024 – July 31, 2026 | 41 | — |
| SFO→MSP San Francisco to Minneapolis | June 28, 2026 – July 31, 2026 | 19 | — |
| SFO→ORD San Francisco to Chicago | May 1–18, 2026 | 14 | — |
| PBI→EWR West Palm Beach to Newark | May 2, 2024 – September 21, 2025 | 30 | — |
| SFO→SEA San Francisco to Seattle | May 1–21, 2025 | 21 | — |
| BWI→ORD Baltimore to Chicago | April 1–30, 2025 | 30 | — |
| SFO→RNO San Francisco to Reno | September 26–30, 2024 | 5 | — |
| SFO→PDX San Francisco to Portland | February 15, 2024 – March 6, 2024 | 21 | — |
| BIL→DEN Billings to Denver | July 1, 2023 – October 28, 2023 | 120 | 90.7% |
| DEN→RSW Denver to Fort Myers | August 1, 2023 – September 4, 2023 | 35 | — |
Because the same number has served different journeys, the statistics above describe only the route UA648 currently operates. Blending them would produce an average of two different flights.
When it goes wrong
The average describes a usual day. This is the day that ruins a connection.
70 min late
against a median of 6 min early
UA648 has an average that understates its risk: a typical arrival is 6 min early, but the worst tenth are 76 minutes worse than that. If the trip has something unmissable at the end of it, the median is the wrong number to plan against.
Percentiles over 956 operations; cancelled and diverted flights are counted separately.
Source: US DOT Bureau of Transportation Statistics · Data covering October 2023 – July 2026
Other flights on this route
Same airports, same journey, different odds of arriving on time.
| Flight | Airline | On time | Median arrival | Operations |
|---|---|---|---|---|
| AS373 | Alaska Airlines | 84.0% | 11 min early | 719 |
| UA648 this flight | United Airlines | 73.9% | 6 min early | 956 |
Every departure listed carries at least 600 operations, so the comparison is between figures that mean something. UA648 is placed in the same ordering rather than left out of it; the rows around it are the most punctual departures on the route, not all of them, so this is a comparison and not a rank. Schedules change; confirm the departure still operates before booking around this.
Data and methodology
Calculated by FlyerIntel from 956 records of UA648 operating EWR → SFO, published by the US DOT Bureau of Transportation Statistics. A flight counts as delayed when it arrives 15 or more minutes after schedule. Cancelled and diverted flights are excluded from the on-time rate and reported separately. Flight numbers are resolved as carrier plus number plus route, because the same number serves different routes over time.
Full methodology · Data sources · Report a problem
Related research: Most and Least Reliable Flight Numbers · The Delay You Inherit · Making Up Time in the Air
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