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Flight Reliability

UA 5666 · United Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and UA 5666 moved between routes during this period. Numbers below combine all of them, so treat them as background, not a verdict. For a cleaner answer, check the route you are actually flying.

Combined across all its routes

80%
Arrive within 15 minutes
13 min
Average arrival delay
1.6%
Cancelled
5 min early
Median arrival delay

Based on 320 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon82%(45 flights)
  • Tue81%(41 flights)
  • Wed76%(45 flights)
  • Thu78%(45 flights)
  • Fri76%(46 flights)
  • Sat77%(44 flights)
  • Sun90%(49 flights)
On-time by departure window
  • 6–9 AM82%(161 flights)
  • 9 AM–12 PM88%(24 flights)
  • 3–6 PM77%(119 flights)
  • 6–9 PM64%(11 flights)
On-time trend by month
64%
May

Jun 73% → May 64% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202573%30
July 202587%31
August 202581%31
September 202597%30
October 202569%29
November 202591%23
December 202569%29
January 202687%31
February 202691%11
March 202688%24
April 202667%21
May 202664%25
Departures on time
84%
Diverted
0%
Flights flown
315
Months covered
12

Keep nerding

Based on 320 historical flights, because apparently we checked. Historical flight data: U.S. Bureau of Transportation Statistics, June 2025 – May 2026. Data through May 2026. How we calculate this.