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(UA) United Airlines 4521 On-Time Performance Rating

Date Range:

01-Sep-2026 to 31-Oct-2026

(GSP) Greenville-Spartanburg International Airport

Greenville, SC, US

(IAD) Washington Dulles International Airport

Dulles, VA, US

On-Time Performance Chart

(using rounded numbers)
On-Time
7
88%
Late
0
0%
Very Late
0
0%
Excessive
1
13%
Cancelled
0
0%
Diverted
0
0%

Delay Statistics

(Aggregate Arrival Delay Statistics for this Flight)

Total Flights Observed
8
Total Delays ( > 1 min )
2
Codeshares
8
Average Delay (min.)
33.5
Standard Deviation
44.5
Min
0
Max
65

UA 4521 On-Time Performance Details

Overall Rating
3.1 of 5
Average
Percentage On-Time 88%
Average Delay Time 33.5 min
FlightStats Rating is a merit measurement considering both on-time performance and delay severity. The score, 3.1 shows that this flight has on-time performance characteristics better than 60% of all other flights in the FlightStats database.
On-Time Performance Rating
3.8 of 5
Good
Percentage On-Time 88%
This flight has an on-time performance of 88%. Statistically, when taking into consideration sample size, standard deviation, and mean, this flight is on-time more often than 76% of other flights.
Delay Performance
2.3 of 5
Average
Average Delay Time 33.5 min
This flight has an average delay of 33.5 minutes with a standard deviation of 44.5 minutes. Statistically, when taking into consideration sample size, standard deviation, and mean, this flight has delay performance characteristics better than 46% of other flights.

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