Flight profile · Delta Air Lines
DL384
Boston (BOS) to Seattle (SEA) · scheduled 7:25 AM – 10:45 AM
How DL384 performs
1,030 operations, 2023-09-05 to 2026-06-30.
DL384 arrived on time 82.6% of the time, against 75.9% for all BOS → SEA flights — this specific departure is 6.8 percentage points better than the route as a whole. Against Delta Air Lines’s own flights on this route it is 3.3 points better.
Source: US DOT Bureau of Transportation Statistics · 1,030 operations between 2023-09-05 to 2026-06-30
Against the rest of the route
| On time | Cancelled | Median delay | Severe | Flights | |
|---|---|---|---|---|---|
| DL384 | 82.6% | 0.97% | -9 min | 2.3% | 1,030 |
| Delta Air Lines on BOS → SEA | 79.3% | 1.01% | -8 min | 5.6% | 2,863 |
| All BOS → SEA flights | 75.9% | 0.95% | -6 min | 6.9% | 7,588 |
Source: FlyerIntel analysis of US DOT BTS data · 2023-09-05 to 2026-06-30
By day of week
Does DL384 run worse on particular days?
Monday is historically the most reliable day and Tuesday the least, a gap of 8.7 percentage points.
Source: FlyerIntel analysis of US DOT BTS data · 2023-09-05 to 2026-06-30 · Days with fewer than 120 operations are not scored.
Other routes DL384 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 |
|---|---|---|---|
| MSP→RAP Minneapolis to Rapid City | 2023-07-01 – 2023-09-03 | 65 | — |
Because the same number has served different journeys, the statistics above describe only the route DL384 currently operates. Blending them would produce an average of two different flights.
Why DL384 runs late
Where US DOT attributed the delay minutes on this flight.
airspace and airport capacity, including weather-driven flow control
crew, maintenance, boarding, fuelling — within the carrier’s 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 DL384 on BOS → SEA. 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 BOS → SEA
Same airports, same journey — and not the same odds of arriving on time.
| Flight | Airline | On time | Median arrival | Operations |
|---|---|---|---|---|
| AS537 | Alaska Airlines | 76.7% | 6 min early | 600 |
| AS459 | Alaska Airlines | 75.3% | 4 min early | 999 |
| DL324 | Delta Air Lines | 69.8% | 1 min early | 750 |
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 1,030 records of DL384 operating BOS → SEA, 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.
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