Flight profile · Delta Air Lines
DL521
Los Angeles (LAX) to Dallas–Fort Worth (DFW) · scheduled 8:35 AM – 1:23 PM
How DL521 performs
871 operations, 2023-09-05 to 2026-06-27.
DL521 arrived on time 84.6% of the time, against 77.2% for all LAX → DFW flights — this specific departure is 7.4 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 · 871 operations between 2023-09-05 to 2026-06-27
Against the rest of the route
| On time | Cancelled | Median delay | Severe | Flights | |
|---|---|---|---|---|---|
| DL521 | 84.6% | 1.15% | -6 min | 4.9% | 871 |
| Delta Air Lines on LAX → DFW | 81.2% | 0.93% | -5 min | 6.5% | 2,148 |
| All LAX → DFW flights | 77.2% | 1.62% | -6 min | 8.6% | 20,090 |
Source: FlyerIntel analysis of US DOT BTS data · 2023-09-05 to 2026-06-27
By day of week
Does DL521 run worse on particular days?
Sunday is historically the most reliable day and Monday the least, a gap of 12.1 percentage points.
Source: FlyerIntel analysis of US DOT BTS data · 2023-09-05 to 2026-06-27 · Days with fewer than 120 operations are not scored.
Other routes DL521 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 |
|---|---|---|---|
| DFW→LAX Dallas–Fort Worth to Los Angeles | 2023-12-09 – 2026-04-11 | 63 | — |
| ATL→IND Atlanta to Indianapolis | 2024-05-07 – 2024-06-06 | 26 | — |
| BOS→ORD Boston to Chicago | 2024-05-11 – 2024-06-01 | 5 | — |
| DTW→LAS Detroit to Las Vegas | 2024-03-10 – 2024-05-06 | 58 | — |
| LAS→DTW Las Vegas to Detroit | 2024-04-11 – 2024-05-06 | 16 | — |
| JFK→LAX New York to Los Angeles | 2024-01-09 – 2024-03-08 | 39 | — |
| ATL→LAS Atlanta to Las Vegas | 2024-01-12 – 2024-01-13 | 2 | — |
| SEA→MCO Seattle to Orlando | 2023-07-02 – 2023-09-04 | 62 | — |
Because the same number has served different journeys, the statistics above describe only the route DL521 currently operates. Blending them would produce an average of two different flights.
Data and methodology
Calculated by FlyerIntel from 871 records of DL521 operating LAX → DFW, 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.