Skip to content
WanderNerd
Check a flight

Flight Reliability

UA 400 · United Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and UA 400 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

83%
Arrive within 15 minutes
4 min
Average arrival delay
0.8%
Cancelled
7 min early
Median arrival delay

Based on 376 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon87%(55 flights)
  • Tue80%(50 flights)
  • Wed77%(51 flights)
  • Thu84%(51 flights)
  • Fri86%(51 flights)
  • Sat77%(57 flights)
  • Sun86%(57 flights)
On-time by departure window
  • 6–9 AM90%(143 flights)
  • 12–3 PM82%(90 flights)
  • 3–6 PM75%(63 flights)
  • 6–9 PM76%(59 flights)
  • 9 PM–12 AM71%(17 flights)
On-time trend by month
84%
May

Jun 93% → May 84% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202593%28
July 202571%17
August 202577%31
September 202572%29
October 202581%37
November 202586%59
December 202584%32
January 202673%30
February 202678%27
March 202686%22
April 202697%29
May 202684%31
Departures on time
82%
Diverted
0.3%
Flights flown
372
Months covered
12

Keep nerding

Based on 376 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.