Flight profile · Delta Air Lines
DL509
Detroit (DTW) to San Francisco (SFO) · scheduled 8:59 PM – 11:25 PM
How DL509 performs
388 operations, 2024-06-07 to 2026-06-29.
DL509 arrived on time 63.5% of the time, against 74.4% for all DTW → SFO flights — this specific departure is 10.8 percentage points worse than the route as a whole. Against Delta Air Lines’s own flights on this route it is 10.8 points worse.
Source: US DOT Bureau of Transportation Statistics · 388 operations between 2024-06-07 to 2026-06-29
Against the rest of the route
| On time | Cancelled | Median delay | Severe | Flights | |
|---|---|---|---|---|---|
| DL509 | 63.5% | 1.03% | 1 min | 10.2% | 388 |
| Delta Air Lines on DTW → SFO | 74.4% | 0.72% | -3 min | 7.4% | 4,052 |
| All DTW → SFO flights | 74.4% | 0.76% | -4 min | 7.7% | 5,009 |
Source: FlyerIntel analysis of US DOT BTS data · 2024-06-07 to 2026-06-29
Other routes DL509 has flown
A flight number is a slot in a schedule, and carriers reassign it. These are the other city pairs this number served in the analysis period.
| Route | Operated | Flights | On time |
|---|---|---|---|
| BNA→LAX Nashville to Los Angeles | 2026-05-07 – 2026-06-05 | 25 | — |
| SAN→JFK San Diego to New York | 2026-04-13 – 2026-05-06 | 24 | — |
| SNA→SLC Santa Ana to Salt Lake City | 2025-08-11 – 2025-12-19 | 110 | 87.2% |
| BOS→AUS Boston to Austin | 2025-07-12 – 2025-08-09 | 5 | — |
| PBI→ATL West Palm Beach to Atlanta | 2025-04-19 – 2025-05-03 | 3 | — |
| DTW→LGA Detroit to New York | 2025-01-11 – 2025-03-08 | 9 | — |
| ATL→JFK Atlanta to New York | 2025-02-14 – 2025-02-21 | 2 | — |
| TPA→BOS Tampa to Boston | 2025-01-19 – 2025-02-16 | 3 | — |
| BNA→AUS Nashville to Austin | 2024-10-27 – 2024-10-27 | 1 | — |
| DTW→LAS Detroit to Las Vegas | 2024-05-07 – 2024-06-06 | 29 | — |
| SEA→SJC Seattle to San Jose | 2024-05-25 – 2024-05-26 | 2 | — |
| SEA→JFK Seattle to New York | 2024-04-09 – 2024-05-06 | 28 | — |
| EWR→SLC Newark to Salt Lake City | 2024-03-10 – 2024-04-08 | 30 | — |
| SLC→EWR Salt Lake City to Newark | 2024-03-10 – 2024-04-08 | 30 | — |
| MSP→IAH Minneapolis to Houston | 2024-01-13 – 2024-03-09 | 12 | — |
| JFK→LAS New York to Las Vegas | 2023-07-01 – 2024-01-07 | 191 | 93.2% |
| LAS→JFK Las Vegas to New York | 2023-12-24 – 2024-01-06 | 10 | — |
Because the same number has served different journeys, the statistics above describe only the route DL509 currently operates. Blending them would produce an average of two different flights.
Why DL509 runs late
Where US DOT attributed the delay minutes on this flight.
crew, maintenance, boarding, fuelling — within the carrier’s control
airspace and airport capacity, including weather-driven flow control
the inbound aircraft was late, so this flight started late
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for DL509 on DTW → SFO. A single late flight can carry more than one cause, and only delays of fifteen minutes or more are attributed at all.
Other departures on DTW → SFO
Same airports, same journey — and not the same odds of arriving on time.
| Flight | Airline | On time | Median arrival | Operations |
|---|---|---|---|---|
| DL361 | Delta Air Lines | 81.7% | 6 min early | 1,011 |
| DL469 | Delta Air Lines | 75.2% | 2 min early | 789 |
| DL442 | Delta Air Lines | 69.8% | 0 min early | 735 |
Every departure listed carries at least 600 operations, so the comparison is between figures that mean something. Schedules change; confirm the departure still operates before booking around this.
Data and methodology
Calculated by FlyerIntel from 388 records of DL509 operating DTW → SFO, published by the US DOT Bureau of Transportation Statistics. A flight counts as delayed when it arrives 15 or more minutes after schedule. Cancelled and diverted flights are excluded from the on-time rate and reported separately. Flight numbers are resolved as carrier plus number plus route, because the same number serves different routes over time.
Full methodology · Report a problem
Analysis last recomputed