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Flight Reliability

UA 3540 · United Airlines

Washington → Pittsburgh (IAD–PIT)87% of its flights flew this route. The rest (ILM–EWR, LGA–IAD) are included in these numbers.

73
Usually Fine
WanderNerd Reliability Score
78%
Arrive within 15 minutes
10 min
Average arrival delay
3.4%
Cancelled
7 min early
Median arrival delay

Based on 385 historical flights. Data through May 2026.

What the data says

The late departure is the smart one here.

UA 3540 departing between 9 PM–12 AM arrived on time 80% of the time, versus 47% between 6–9 PM.

Sunday scaries are real for this one.

UA 3540 arrived on time 87% of the time on Tuesdays and just 67% on Sundays. That gap is worth planning around.

A bit behind the IAD–PIT route.

UA 3540 arrived on time 78% of the time, versus 85% across the IAD–PIT route.

Keep a backup plan handy.

UA 3540 was cancelled 3.4% of the time. Typical for U.S. flights is around 1–2%.

The breakdown

On-time by weekday
  • Mon83%(53 flights)
  • Tue87%(53 flights)
  • Wed78%(54 flights)
  • Thu76%(54 flights)
  • Fri76%(54 flights)
  • Sat82%(50 flights)
  • Sun67%(54 flights)
On-time by departure window
  • 3–6 PM76%(25 flights)
  • 6–9 PM47%(19 flights)
  • 9 PM–12 AM80%(328 flights)
On-time trend by month
81%
May

Jun 61% → May 81% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202561%33
July 202579%29
August 202574%31
September 202587%30
October 202584%31
November 202575%24
December 202574%31
January 202690%29
February 202689%28
March 202662%45
April 202693%30
May 202681%31
Departures on time
79%
Diverted
0%
Flights flown
372
Months covered
12

Same route, other flights

Keep nerding

Based on 385 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.