About 1 in 9 UA 4857 flights from Manchester arrived 15+ minutes late, diverted or cancelled over the past year (11%); 0.6% were cancelled. The typical flight landed 16 minutes early.
UA 4857: MHT → IAD
Scheduled to leave Manchester at 9:25 a.m. local time, operated by CommutAir as C5 4857. Over the past year it arrived on time 89% of the time (169 flights), in line with other UA flights on the route at that hour (90%). Last seen in the data Aug 31, 2026.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 26 | 88% |
| Tuesday | 24 | 88% |
| Wednesday | 23 | 83% |
| Thursday | 23 | 96% |
| Friday | 24 | 92% |
| Saturday | 24 | 88% |
| Sunday | 25 | 88% |
Why it was late
All flights MHT → IAD · Connecting off UA 4857? Check the risk
Questions
How often is UA 4857 from MHT to IAD late?
United Airlines 4857 from Manchester, NH to Washington, DC arrived 15 or more minutes late, was diverted or was cancelled on 11% of 169 scheduled flights between September 2025 and August 2026. 0.6% were cancelled.
Flight numbers change. Figures cover flights with this airline, number and route only. "Likely range" is the 95% interval for the true on-time rate given the number of flights. This is history, not live status: check United Airlines for today's flight. Method.