Flight Reliability
UA 4034 · United Airlines
Kansas City → Washington (MCI–IAD)89% of its flights flew this route. The rest (ECP–IAH, IAD–PIT) are included in these numbers.
- 88%
- Arrive within 15 minutes
- 4 min early
- Average arrival delay
- 0.9%
- Cancelled
- 12 min early
- Median arrival delay
Based on 227 historical flights. Data through May 2026.
What the data says
The 6–9 AM departure wins.
UA 4034 departing between 6–9 AM arrived on time 93% of the time, versus 60% between 9 AM–12 PM.
Wednesdays have been rough.
UA 4034 arrived on time 94% of the time on Fridays and just 77% on Wednesdays. That gap is worth planning around.
Better than the United Airlines network average.
UA 4034 arrived on time 88% of the time, versus 79% across the United Airlines network.
Recent months have been rougher.
UA 4034 arrived on time 84% of the time over the last three months in the data, compared with 93% in the three months before that.
The breakdown
- Mon77%(31 flights)
- Tue94%(31 flights)
- Wed77%(31 flights)
- Thu87%(30 flights)
- Fri94%(36 flights)
- Sat94%(36 flights)
- Sun90%(30 flights)
- 6–9 AM93%(15 flights)
- 9 AM–12 PM60%(10 flights)
- 3–6 PM89%(199 flights)
- 6–9 PM—(1 flights)
Oct 86% → May 77% on time
| Month | On-time percentage | Flights |
|---|---|---|
| October 2025 | 86% | 14 |
| November 2025 | 87% | 30 |
| December 2025 | 90% | 31 |
| January 2026 | 93% | 30 |
| February 2026 | 96% | 28 |
| March 2026 | 77% | 30 |
| April 2026 | 100% | 30 |
| May 2026 | 77% | 30 |
- Departures on time
- 90%
- Diverted
- 0%
- Flights flown
- 225
- Months covered
- 9
Same route, other flights
Keep nerding
Based on 227 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.