Flight profile · Delta Air Lines
DL400
San Francisco (SFO) to Boston (BOS) · scheduled 7:10 AM – 4:10 PM
How DL400 performs
753 operations, 2024-06-07 to 2026-06-30.
DL400 arrived on time 90.4% of the time, against 78.2% for all SFO → BOS flights — this specific departure is 12.2 percentage points better than the route as a whole. Against Delta Air Lines’s own flights on this route it is 12.5 points better.
Source: US DOT Bureau of Transportation Statistics · 753 operations between 2024-06-07 to 2026-06-30
Against the rest of the route
| On time | Cancelled | Median delay | Severe | Flights | |
|---|---|---|---|---|---|
| DL400 | 90.4% | 1.46% | -13 min | 2.6% | 753 |
| Delta Air Lines on SFO → BOS | 77.9% | 1.03% | -6 min | 7.7% | 2,425 |
| All SFO → BOS flights | 78.2% | 0.95% | -7 min | 8.3% | 13,718 |
Source: FlyerIntel analysis of US DOT BTS data · 2024-06-07 to 2026-06-30
Other routes DL400 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 |
|---|---|---|---|
| SFO→DTW San Francisco to Detroit | 2023-07-01 – 2024-06-06 | 187 | 91.9% |
| SNA→SLC Santa Ana to Salt Lake City | 2024-04-09 – 2024-05-06 | 24 | — |
| DEN→ATL Denver to Atlanta | 2024-03-10 – 2024-04-08 | 30 | — |
| SLC→BOS Salt Lake City to Boston | 2024-01-08 – 2024-03-09 | 62 | — |
| DTW→SFO Detroit to San Francisco | 2023-09-06 – 2023-12-14 | 18 | — |
| ATL→LAS Atlanta to Las Vegas | 2023-10-28 – 2023-11-04 | 8 | — |
Because the same number has served different journeys, the statistics above describe only the route DL400 currently operates. Blending them would produce an average of two different flights.
Data and methodology
Calculated by FlyerIntel from 753 records of DL400 operating SFO → BOS, 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.