Flight AS421
Alaska Airlines flight AS421
Looking for AS421 in the air…
Seattle (SEA) to Fairbanks (FAI)
Historically, this flight arrives 15+ minutes late 19% of the time, and when it is late the delay averages 38 minutes. It was cancelled 0.0% of the time.
- On-time arrivals
- 81.0%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 38 min
- Flights arriving 15+ minutes late
- Flights tracked
- 21
- Scheduled flights in the period
What caused the delays
- Airline (crew, maintenance, cleaning) 48%
- Air traffic control & airport 30%
- Late-arriving aircraft 22%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Seattle (SEA) to Boston (BOS)
Only 1 flight on record, which is too few for reliable odds.
- On-time arrivals
- 100.0%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- —
- Flights arriving 15+ minutes late
- Flights tracked
- 1
- Scheduled flights in the period
Oct 2025
May 2026
Show as table
| Month | On time | Flights |
|---|---|---|
| October 2025 | 100.0% | 1 |
| April 2026 | 66.7% | 9 |
| May 2026 | 91.7% | 12 |
Source: U.S. DOT Bureau of Transportation Statistics on-time data, September 2025 – August 2026. Covers flights operated by reporting U.S. carriers. About our data