Flight OddsUA4257 IAD → TYS
United Airlines · Washington, DC to Knoxville, TN · 335 flights observed, 2025-07-01 to 2026-06-30 · 420 mi
UA4257 covers more than one route in the data window — the stats below are for IAD → TYS, the one it has flown most recently. The others are linked under “Other routes”.
On-time arrival
82%
Median delay
-12 min
90th percentile
+85 min
Cancellation rate
1%
How often is UA4257 on time?
Across 335 flights on IAD → TYS from 2025-07-01 to 2026-06-30, UA4257 arrived within 15 minutes of schedule 82% of the time. The median arrival delay was -12 min, and the worst 10% of flights arrived +85 min or later. 1% of flights were cancelled.
Delay distribution
Arrival delay for completed flights (excludes cancellations and diversions).
| Arrival | Flights | Share |
|---|---|---|
| Early / on-time | 271 | 82% |
| 16-30 min | 12 | 4% |
| 31-60 min | 10 | 3% |
| 61-120 min | 6 | 2% |
| 2+ hrs | 32 | 10% |
Performance by month
| Month | Flights | On-time | Avg delay |
|---|---|---|---|
| 2025-07 | 31 | 94% | +7 min |
| 2025-08 | 25 | 68% | +16 min |
| 2025-09 | 29 | 86% | +1 min |
| 2025-10 | 31 | 94% | -6 min |
| 2025-11 | 28 | 96% | -7 min |
| 2025-12 | 31 | 71% | +12 min |
| 2026-01 | 28 | 79% | +4 min |
| 2026-02 | 28 | 86% | +0 min |
| 2026-03 | 30 | 77% | +8 min |
| 2026-04 | 29 | 97% | -16 min |
| 2026-05 | 11 | 55% | +61 min |
| 2026-06 | 30 | 63% | +58 min |
Performance by day of week
| Day | Flights | On-time |
|---|---|---|
| Mon | 47 | 81% |
| Tue | 48 | 81% |
| Wed | 47 | 87% |
| Thu | 44 | 82% |
| Fri | 49 | 76% |
| Sat | 48 | 92% |
| Sun | 48 | 75% |
Other routes
Related
Based on US Department of Transportation Bureau of Transportation Statistics on-time data. Loading live conditions and full charts…