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(UA) United Airlines 521 On-Time Performance Rating

Date Range:

15-Jan-2026 to 15-Mar-2026

(ATL) Atlanta Hartsfield-Jackson International Airport

Atlanta, GA, US

(IAH) Houston George Bush Intercontinental Airport

Houston, TX, US

On-Time Performance Chart

(using rounded numbers)
On-Time
40
87%
Late
1
2%
Very Late
2
4%
Excessive
2
4%
Cancelled
0
0%
Diverted
1
2%

Delay Statistics

(Aggregate Arrival Delay Statistics for this Flight)

Total Flights Observed
45
Total Delays ( > 1 min )
10
Codeshares
0
Average Delay (min.)
64.5
Standard Deviation
108.8
Min
0
Max
314

UA 521 On-Time Performance Details

Overall Rating
2.6 of 5
Average
Percentage On-Time 89%
Average Delay Time 64.5 min
FlightStats Rating is a merit measurement considering both on-time performance and delay severity. The score, 2.6 shows that this flight has on-time performance characteristics better than 50% of all other flights in the FlightStats database.
On-Time Performance Rating
4.9 of 5
Very Good
Percentage On-Time 89%
This flight has an on-time performance of 89%. Statistically, when taking into consideration sample size, standard deviation, and mean, this flight is on-time more often than 98% of other flights.
Delay Performance
0.2 of 5
Very Poor
Average Delay Time 64.5 min
This flight has an average delay of 64.5 minutes with a standard deviation of 108.8 minutes. Statistically, when taking into consideration sample size, standard deviation, and mean, this flight has delay performance characteristics better than 4% of other flights.

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