Flight OddsUA4478 PWM → IAD
United Airlines · Portland, ME to Washington, DC · 89 flights observed, 2026-01-06 to 2026-04-29 · 493 mi
UA4478 covers more than one route in the data window — the stats below are for PWM → IAD, the one it has flown most recently. The others are linked under “Other routes”.
On-time arrival
89%
Median delay
-18 min
90th percentile
+16 min
Cancellation rate
4%
How often is UA4478 on time?
Across 89 flights on PWM → IAD from 2026-01-06 to 2026-04-29, UA4478 arrived within 15 minutes of schedule 89% of the time. The median arrival delay was -18 min, and the worst 10% of flights arrived +16 min or later. 4% of flights were cancelled.
Delay distribution
Arrival delay for completed flights (excludes cancellations and diversions).
| Arrival | Flights | Share |
|---|---|---|
| Early / on-time | 76 | 89% |
| 16-30 min | 3 | 4% |
| 31-60 min | 1 | 1% |
| 61-120 min | 3 | 4% |
| 2+ hrs | 2 | 2% |
Performance by month
| Month | Flights | On-time | Avg delay |
|---|---|---|---|
| 2026-01 | 24 | 92% | -4 min |
| 2026-02 | 25 | 84% | -2 min |
| 2026-03 | 7 | 86% | +4 min |
| 2026-04 | 29 | 93% | -15 min |
Performance by day of week
| Day | Flights | On-time |
|---|---|---|
| Mon | 11 | 91% |
| Tue | 13 | 69% |
| Wed | 14 | 93% |
| Thu | 11 | 100% |
| Fri | 12 | 83% |
| Sat | 12 | 100% |
| Sun | 12 | 92% |
Other routes
Related
Based on US Department of Transportation Bureau of Transportation Statistics on-time data. Loading live conditions and full charts…