Alpine Air Express (AIP) on-time performance, September 2026
1,716 scheduled Alpine Air Express departures in US airspace in September 2026, 68.8% of them on time. Measured from FAA departure data, updated every morning.
On time, day by day
Share of Alpine Air Express departures within 15 minutes of schedule, by day. Light bars show each day's departures for context. Worst day: Thursday 10 September at 57.1%. Best: Sunday 13 September at 100.0%.
Airports, ranked by on-time share
Airports with at least 30 Alpine Air Express departures in the month.
| Airport | Departures | On time | 45+ min late | Avg delay (min) |
|---|---|---|---|---|
| FCA Kalispell | 41 | 95.1% | 0.0% | -11.5 |
| BIS Bismarck | 39 | 94.9% | 0.0% | -29.4 |
| FSD Sioux Falls | 73 | 82.2% | 9.6% | 3.3 |
| FAR Fargo | 108 | 68.5% | 7.4% | 3.6 |
| MSO Missoula | 43 | 67.4% | 2.3% | 2.2 |
| RAP Rapid City | 40 | 62.5% | 25.0% | 18.6 |
| ABR Aberdeen | 40 | 52.5% | 2.5% | 5.8 |
| BIL Billings | 244 | 49.6% | 13.1% | 16.4 |
| SLC Salt Lake City | 174 | 36.2% | 29.9% | 34.1 |
| DEN Denver | 79 | 35.4% | 16.5% | 22.6 |
Least punctual routes
Routes with at least 20 Alpine Air Express departures, lowest on-time share first.
| Route | Flights | On time | Avg delay |
|---|---|---|---|
| SLC to KVEL Salt Lake City to | 21 | 0.0% | 107.3 |
| IDA to SLC Idaho Falls to Salt Lake City | 20 | 0.0% | 32.8 |
| BIL to GTF Billings to Great Falls | 21 | 14.3% | 36.6 |
| BIL to KGCC Billings to | 24 | 16.7% | 36.8 |
| SLC to IDA Salt Lake City to Idaho Falls | 23 | 17.4% | 35.0 |
| BIL to BTM Billings to Butte | 22 | 18.2% | 28.9 |
| DEN to HDN Denver to Hayden | 21 | 19.0% | 27.6 |
| SLC to KRKS Salt Lake City to | 20 | 20.0% | 35.6 |
| ABR to FSD Aberdeen to Sioux Falls | 23 | 21.7% | 14.4 |
| SLC to JAC Salt Lake City to Jackson | 21 | 23.8% | 32.3 |
Busiest routes
The ten routes Alpine Air Express flew most this month.
| Route | Flights | On time | Avg delay |
|---|---|---|---|
| FSD to RAP Sioux Falls to Rapid City | 42 | 85.7% | 2.3 |
| BIL to MSO Billings to Missoula | 42 | 54.8% | 12.0 |
| RAP to FSD Rapid City to Sioux Falls | 40 | 62.5% | 18.6 |
| BIL to FCA Billings to Kalispell | 37 | 51.4% | 18.9 |
| FCA to BIL Kalispell to Billings | 35 | 94.3% | -12.8 |
| HLN to BIL Helena to Billings | 26 | 100.0% | -15.0 |
| FAR to BIS Fargo to Bismarck | 25 | 76.0% | 3.1 |
| GCK to ICT Garden City to Wichita | 25 | 100.0% | -22.8 |
| FAR to MOT Fargo to Minot | 25 | 76.0% | -3.2 |
| ICT to GCK Wichita to Garden City | 25 | 76.0% | 3.8 |
Other months for Alpine Air Express
Airport pages for September 2026
How we measure
On time means the aircraft took off within 15 minutes of its scheduled departure, after subtracting the departure airport's normal taxi time (FAA SWIM reports wheels-off, not push-back, so the median taxi time of the last 30 days is taken off every flight first). Average delay is the mean of that taxi-adjusted delay over all departures; early departures count as negative minutes, so an operator that routinely leaves early can show a negative average. 45+ min late is the share of departures that left 45 minutes or more behind schedule, the point at which most connections are at risk.
Scope: scheduled airlines only, the same set as the monthly State of the Sky report (operators with published routes; private, fractional and charter operators are left out), so the two publications give the same numbers for the same month. Departures are counted by scheduled day (UTC). Each day's flights are rolled up overnight and published the next morning; the newest day keeps filling in for a day or two and is only shown once it is substantially complete. Figures can differ by a few tenths of a point from the State of the Sky report for the same month: that report is frozen on the 2nd of the following month, while these pages are rebuilt from the live rollup, which recomputes each airport's taxi baseline nightly and re-rolls the last week of the month as late departure times arrive (September 2026 at SFO: 16,398 departures in both, 69.2% on time here against 69.5% in the report).
Source: FAA System Wide Information Management (SWIM) flight plans and departure times, processed by PlaneTrack. Free to quote with credit to PlaneTrack (CC BY 4.0).