(UA) United Airlines 521 On-Time Performance Rating

Date Range:

15-Jan-2026 to 15-Mar-2026

(BOS) Boston Logan International Airport

Boston, MA, US

(EWR) Newark Liberty International Airport

Newark, NJ, US

On-Time Performance Chart

(using rounded numbers)

On-Time

90%

Late

Very Late

10%

Excessive

Cancelled

Diverted

Delay Statistics

(Aggregate Arrival Delay Statistics for this Flight)

Total Flights Observed

Total Delays ( > 1 min )

Codeshares

Average Delay (min.)

20.333333333333332

Standard Deviation

Min

Max

UA 521 On-Time Performance Details

Overall Rating

3.8 of 5

Good

Percentage On-Time 90%

Average Delay Time 20.333333333333332 min

FlightStats Rating is a merit measurement considering both on-time performance and delay severity. The score, 3.8 shows that this flight has on-time performance characteristics better than 75% of all other flights in the FlightStats database.

On-Time Performance Rating

4.3 of 5

Good

Percentage On-Time 90%

This flight has an on-time performance of 90%. Statistically, when taking into consideration sample size, standard deviation, and mean, this flight is on-time more often than 86% of other flights.

Delay Performance

3.3 of 5

Average

Average Delay Time 20.333333333333332 min

This flight has an average delay of 20.333333333333332 minutes with a standard deviation of 21 minutes. Statistically, when taking into consideration sample size, standard deviation, and mean, this flight has delay performance characteristics better than 66% of other flights.