Flight profile · Delta Air Lines
DL1585
Atlanta (ATL) to Houston (IAH) · scheduled 7:05 AM – 8:43 AM
How DL1585 performs
942 operations, September 2023 – July 2026.
DL1585 arrived on time 84.9% of the time, against 75.4% for all ATL → IAH flights, so this departure is 9.5 percentage points better than the route as a whole. Against Delta Air Lines’ own flights on this route it is 8.8 points better.
DL1585’s scheduled departure has moved during the period FlyerIntel has on file: it typically left around 7:00 AM earlier on, and around 7:30 AM more recently — a 30-minute shift, not the few minutes of day-to-day rounding every published schedule carries. Confirm the current departure time before booking around an older listing.
Source: US DOT Bureau of Transportation Statistics · 942 operations, September 2023 – July 2026 · If DL1585 is cancelled or significantly changed, DOT’s automatic refund rule may entitle you to your money back. The refund checker walks through eligibility.
Where DL1585 is right now
A live reading, only if you ask for it. It is not part of the reliability record above.
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Against the rest of the route
| Flight or route | On time | Cancelled | Median delay | Severe | Flights |
|---|---|---|---|---|---|
| DL1585 | 84.9% | 2.12% | -4 min | 1.8% | 942 |
| Delta Air Lines on ATL → IAH | 76.1% | 1.49% | -2 min | 7.3% | 7,359 |
| All ATL → IAH flights | 75.4% | 1.66% | -3 min | 8.9% | 14,365 |
Source: FlyerIntel analysis of US DOT BTS data · September 2023 – July 2026
Why DL1585 runs late
Where US DOT attributed the delay minutes on this flight.
airspace and airport capacity, including weather-driven flow control
crew, maintenance, boarding and fueling, all within the carrier’s control
weather severe enough to stop this flight specifically
the inbound aircraft was late, so this flight started late
Share of the delay minutes US DOT attributed to each cause for DL1585 on ATL → IAH. Only delays of 15 minutes or more are attributed.
Source: US DOT Bureau of Transportation Statistics · Data covering September 2023 – July 2026
Does a late aircraft delay this flight?
How often the plane that flies DL1585 comes in late, and what that does to the departure.
DL1585 is usually the aircraft’s first flight of the day: the schedule gives it a median of 7.9 hours on the ground at ATL, so its “inbound” is mostly the aircraft’s arrival the evening before.
When the aircraft came in 15 or more minutes late, DL1585 pushed back an average of 5 minutes late; when it came in on time or early, an average of 0 minutes late.
Each departure is matched to the flight the same aircraft flew into ATL just before it, using the tail number in the DOT file, 782 of 922 departures in all. A departure is left out when that flight is unknown, was cancelled or diverted, or the aircraft had sat for more than 12 hours. A flight the airline cancelled never left and is not in the count, and one flown by a substitute aircraft is matched to the aircraft that flew it, not to the one first planned.
Against the network at the same turn length
| Share of departures | Inbound landed 15+ late | Left 15+ late after a late inbound | Left 15+ late after an on-time inbound |
|---|---|---|---|
| DL1585 | 19% | 12% | 6% |
| Network, same turn | 29% | 12% | 9% |
A night on the ground absorbs most of a late arrival, so a late inbound matters far less on a turn this long than on a same-day one.
The network row is every flight with a scheduled turn of 6 hours or more, usually overnight. How often DL1585’s aircraft landed 15 or more minutes late is lower than the network’s and, once the aircraft was late, how often DL1585 left 15 or more minutes late is about the same as the network’s.
More: Which Flight Numbers Pay for a Late Aircraft lists the flight numbers that pass a late aircraft on.
Source: US DOT Bureau of Transportation Statistics · Data covering September 2023 – July 2026
From pushback to gate
When it leaves ATL late, does that still matter by the time it reaches IAH?
On arrival at IAH, DL1585 spends 8.0 min taxiing from touchdown to the gate — ground time a connecting passenger sits through before they can even leave the aircraft, on top of however late the flight itself ran. That is 2.7 minutes shorter than a typical IAH arrival (10.7 min).
Departure delay is averaged over every pushback and arrival delay over every completed arrival, so the two counts differ by the flights that never reached IAH. Taxi-out is gate to wheels up and sits inside the scheduled block rather than on top of it; the comparison is 45,565 departures from ATL scheduled in the clock hour DL1585 most often leaves in. Taxi-in is landing to gate, compared against every arrival FlyerIntel has on file at IAH (359,471 flights), not just DL1585’s own. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · September 2023 – July 2026
The hour it leaves ATL
Part of any flight’s record belongs to the clock rather than to the flight. DL1585 has one departure time, so this is what that time is worth.
On-time arrival rate. 45,565 departures from ATL are scheduled in the 7 AM–8 AM hour over the period, against 1,012,247 across the whole day.
DL1585 is scheduled out of ATL at 7:05 AM, in the 7 AM–8 AM bank. Departures from ATL in that hour arrive on time 87.6% of the time against 78.7% across the airport’s whole day — the slot alone is worth 8.8 points better before anything about this particular flight is considered.
The two airport figures cover every departure from ATL to every destination, so they describe the slot rather than this journey — the like-for-like comparison against the route is above. Hours are scheduled local, and a number whose schedule moved between banks inside the period has no single hour and is not described here at all. Why the hour matters.
Source: FlyerIntel analysis of US DOT BTS data · September 2023 – July 2026 · Hours below 120 departures are not scored.
By day of week
Does DL1585 run worse on particular days?
Monday is historically the most reliable day and Wednesday the least, a gap of 6.1 percentage points.
Source: FlyerIntel analysis of US DOT BTS data · September 2023 – July 2026 · Days with fewer than 120 operations are not scored.
Other routes DL1585 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 |
|---|---|---|---|
| IAH→ATL Houston to Atlanta | September 5, 2023 – July 31, 2026 | 893 | 83.9% |
| MEM→ATL Memphis to Atlanta | February 1–5, 2024 | 5 | — |
| ATL→GPT Atlanta to Gulfport | December 17, 2023 – January 7, 2024 | 11 | — |
| GPT→ATL Gulfport to Atlanta | December 17, 2023 – January 7, 2024 | 11 | — |
| CHS→ATL Charleston to Atlanta | July 1, 2023 – September 4, 2023 | 64 | — |
Because the same number has served different journeys, the statistics above describe only the route DL1585 currently operates. Blending them would produce an average of two different flights.
When it goes wrong
The average describes a usual day. This is the day that ruins a connection.
21 min late
against a median of 4 min early
Percentiles over 942 operations; cancelled and diverted flights are counted separately.
Source: US DOT Bureau of Transportation Statistics · Data covering September 2023 – July 2026
Other flights on this route
Same airports, same journey, different odds of arriving on time.
| Flight | Airline | On time | Median arrival | Operations |
|---|---|---|---|---|
| DL1585 this flight | Delta Air Lines | 84.9% | 4 min early | 942 |
| DL1682 | Delta Air Lines | 82.8% | 6 min early | 991 |
| DL1572 | Delta Air Lines | 80.1% | 4 min early | 869 |
| F91403 | Frontier Airlines | 75.4% | 7 min early | 712 |
| DL1223 | Delta Air Lines | 73.6% | 0 min early | 740 |
| DL1601 | Delta Air Lines | 71.6% | 0 min early | 1,119 |
| DL1284 | Delta Air Lines | 71.3% | 0 min early | 998 |
Every departure listed carries at least 600 operations, so the comparison is between figures that mean something. DL1585 is placed in the same ordering rather than left out of it; the rows around it are the most punctual departures on the route, not all of them, so this is a comparison and not a rank. Schedules change; confirm the departure still operates before booking around this.
Data and methodology
Calculated by FlyerIntel from 942 records of DL1585 operating ATL → IAH, 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 · Data sources · Report a problem
Related research: Most and Least Reliable Flight Numbers · The Delay You Inherit · Making Up Time in the Air
Analysis last recomputed