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(UA) United Airlines 4257 On-Time Performance Rating

Date Range:

01-Aug-2026 to 30-Sep-2026

(IAD) Washington Dulles International Airport

Dulles, VA, US

(TYS) Knoxville McGhee Tyson Airport

Knoxville, TN, US

On-Time Performance Chart

(using rounded numbers)
On-Time
38
84%
Late
3
7%
Very Late
0
0%
Excessive
4
9%
Cancelled
0
0%
Diverted
0
0%

Delay Statistics

(Aggregate Arrival Delay Statistics for this Flight)

Total Flights Observed
45
Total Delays ( > 1 min )
9
Codeshares
45
Average Delay (min.)
83.66666666666667
Standard Deviation
102.2
Min
0
Max
316

UA 4257 On-Time Performance Details

Overall Rating
2.4 of 5
Average
Percentage On-Time 84%
Average Delay Time 83.66666666666667 min
FlightStats Rating is a merit measurement considering both on-time performance and delay severity. The score, 2.4 shows that this flight has on-time performance characteristics better than 46% of all other flights in the FlightStats database.
On-Time Performance Rating
4.7 of 5
Very Good
Percentage On-Time 84%
This flight has an on-time performance of 84%. Statistically, when taking into consideration sample size, standard deviation, and mean, this flight is on-time more often than 93% of other flights.
Delay Performance
0.0 of 5
Very Poor
Average Delay Time 83.66666666666667 min
This flight has an average delay of 83.66666666666667 minutes with a standard deviation of 102.2 minutes. Statistically, when taking into consideration sample size, standard deviation, and mean, this flight has delay performance characteristics better than 0% of other flights.