Flight profile · United Airlines
UA755
Washington (IAD) to Boston (BOS) · scheduled 10:18 PM – 11:59 PM
How UA755 performs
600 operations, October 2024 – July 2026.
UA755 arrived on time 79.5% of the time, against 77.5% for all IAD → BOS flights, so this departure is 2.0 percentage points better than the route as a whole. Against United Airlines’ own flights on this route it is 2.0 points better.
Source: US DOT Bureau of Transportation Statistics · 600 operations, October 2024 – July 2026 · If UA755 is cancelled or significantly changed, DOT’s automatic refund rule may entitle you to your money back. The refund checker walks through eligibility.
Where UA755 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 |
|---|---|---|---|---|---|
| UA755 | 79.5% | 1.83% | -4 min | 7.0% | 600 |
| United Airlines on IAD → BOS | 77.5% | 1.53% | -5 min | 9.1% | 4,585 |
| All IAD → BOS flights | 77.5% | 1.68% | -5 min | 9.1% | 4,651 |
Source: FlyerIntel analysis of US DOT BTS data · October 2024 – July 2026
Why UA755 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 UA755 on IAD → BOS. Only delays of 15 minutes or more are attributed.
Source: US DOT Bureau of Transportation Statistics · Data covering October 2024 – July 2026
Does a late aircraft delay this flight?
How often the plane that flies UA755 comes in late, and what that does to the departure.
The aircraft flying UA755 came in 15 or more minutes late on 17% 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 IAD just before it, using the tail number in the DOT file, 411 of 591 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 |
|---|---|
| UA755 | 17% |
| Network, same turn | 17% |
The schedule leaves a normal turn: enough time to clean and board if the aircraft is on time, little to spare if it is not.
The network row is every flight with a scheduled turn of 60 to 89 minutes. How often UA755’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 2024 – July 2026
From pushback to gate
When it leaves IAD late, does that still matter by the time it reaches BOS?
UA755 pushes back an average of 14.1 minutes late and reaches the gate at BOS an average of 7.7 minutes late. The 6.3 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 21.9 minutes on the taxiways at IAD, 1.2 minutes longer than a typical IAD departure in the same hour.
On arrival at BOS, UA755 spends 5.5 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 3.4 minutes shorter than a typical BOS arrival (9.0 min).
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 BOS. Taxi-out is gate to wheels up and sits inside the scheduled block rather than on top of it; the comparison is 17,830 departures from IAD scheduled in the clock hour UA755 most often leaves in. Taxi-in is landing to gate, compared against every arrival FlyerIntel has on file at BOS (440,886 flights), not just UA755’s own. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · October 2024 – July 2026
The hour it leaves IAD
Part of any flight’s record belongs to the clock rather than to the flight. UA755 has one departure time, so this is what that time is worth.
On-time arrival rate. 17,830 departures from IAD are scheduled in the 10 PM–11 PM hour over the period, against 170,208 across the whole day.
UA755 is scheduled out of IAD at 10:18 PM, in the 10 PM–11 PM bank. Departures from IAD in that hour arrive on time 78.7% of the time against 81.0% across the airport’s whole day, so the hour UA755 leaves in is an ordinary one for IAD and explains nothing about its record either way.
The two airport figures cover every departure from IAD 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 2024 – July 2026 · Hours below 120 departures are not scored.
Other routes UA755 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 |
|---|---|---|---|
| IAH→SAT Houston to San Antonio | July 3–4, 2026 | 2 | — |
| SEA→IAD Seattle to Washington | August 1, 2023 – May 20, 2026 | 56 | — |
| SFO→IAD San Francisco to Washington | March 6, 2025 – April 29, 2026 | 101 | 76.0% |
| RNO→SFO Reno to San Francisco | March 5, 2026 – April 29, 2026 | 53 | — |
| SAN→IAD San Diego to Washington | March 30, 2025 – December 17, 2025 | 260 | 84.9% |
| PHX→SFO Phoenix to San Francisco | March 6–29, 2025 | 24 | — |
| PHX→IAD Phoenix to Washington | October 29, 2023 – March 5, 2025 | 207 | 86.0% |
| ORD→PHX Chicago to Phoenix | February 15, 2024 – December 2, 2024 | 292 | 83.7% |
| RDU→ORD Raleigh–Durham to Chicago | June 27, 2024 – August 18, 2024 | 53 | — |
| MIA→DEN Miami to Denver | January 9, 2024 – February 14, 2024 | 37 | — |
| IAH→RNO Houston to Reno | December 21, 2023 – January 8, 2024 | 19 | — |
| IAH→SFO Houston to San Francisco | December 20, 2023 | 1 | — |
| IAD→CLE Washington to Cleveland | July 1, 2023 – October 28, 2023 | 119 | 78.8% |
| LAX→IAD Los Angeles to Washington | July 5–31, 2023 | 24 | — |
Because the same number has served different journeys, the statistics above describe only the route UA755 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.
44 min late
against a median of 4 min early
Percentiles over 600 operations; cancelled and diverted flights are counted separately.
Source: US DOT Bureau of Transportation Statistics · Data covering October 2024 – July 2026
Other flights on this route
Same airports, same journey, different odds of arriving on time.
| Flight | Airline | On time | Median arrival | Operations |
|---|---|---|---|---|
| UA641 | United Airlines | 91.7% | 10 min early | 1,103 |
| UA755 this flight | United Airlines | 79.5% | 4 min early | 600 |
| UA688 | United Airlines | 61.7% | 4 min late | 1,036 |
Every departure listed carries at least 600 operations, so the comparison is between figures that mean something. UA755 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 600 records of UA755 operating IAD → BOS, 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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