Flight profile · Delta Air Lines
DL1389
Houston (IAH) to Detroit (DTW) · scheduled 5:30 AM – 9:05 AM
How DL1389 performs
1,065 operations, July 2023 – July 2026.
DL1389 arrived on time 89.7% of the time, against 80.2% for all IAH → DTW 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 7.2 points better.
Source: US DOT Bureau of Transportation Statistics · 1,065 operations, July 2023 – July 2026 · If DL1389 is cancelled or significantly changed, DOT’s automatic refund rule may entitle you to your money back. The refund checker walks through eligibility.
What stands out
How DL1389 compares to other flight numbers, not just to itself.
Every day of the week performs about the same on this flight, steadier than 96% of 1,710 comparable flight numbers.
91.9% on time on the best day (Tuesday) against 88.0% on the worst (Sunday).
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · The one thing about this specific departure that ranks most extreme against every other published flight number, out of everything FlyerIntel checks — shown only when something clears a real statistical bar, not for every flight.
Where DL1389 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 |
|---|---|---|---|---|---|
| DL1389 | 89.7% | 1.60% | -10 min | 3.8% | 1,065 |
| Delta Air Lines on IAH → DTW | 82.5% | 0.96% | -8 min | 6.5% | 4,044 |
| All IAH → DTW flights | 80.2% | 1.21% | -6 min | 7.3% | 7,048 |
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026
Why DL1389 runs late
Where US DOT attributed the delay minutes on this flight.
crew, maintenance, boarding and fueling, all within the carrier’s control
the inbound aircraft was late, so this flight started late
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for DL1389 on IAH → DTW. Only delays of 15 minutes or more are attributed.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
Does a late aircraft delay this flight?
How often the plane that flies DL1389 comes in late, and what that does to the departure.
DL1389 is usually the aircraft’s first flight of the day: the schedule gives it a median of 6.6 hours on the ground at IAH, so its “inbound” is mostly the aircraft’s arrival the evening before.
When the aircraft came in 15 or more minutes late, DL1389 pushed back an average of 15 minutes late; when it came in on time or early, an average of 2 minutes late.
Each departure is matched to the flight the same aircraft flew into IAH just before it, using the tail number in the DOT file, 977 of 1,049 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 |
|---|---|---|---|
| DL1389 | 24% | 12% | 8% |
| 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 DL1389’s aircraft landed 15 or more minutes late is lower than the network’s and, once the aircraft was late, how often DL1389 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 July 2023 – July 2026
From pushback to gate
When it leaves IAH late, does that still matter by the time it reaches DTW?
DL1389 pushes back an average of 9.4 minutes late and reaches the gate at DTW an average of 3.4 minutes late. The 5.9 minutes between those two figures are slack the published schedule already carries, which is why a late pushback on this flight does not reliably become a late arrival. It spends 13.1 minutes on the taxiways at IAH, 1.9 minutes shorter than a typical IAH departure in the same hour.
On arrival at DTW, DL1389 spends 10.3 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 1.0 minutes longer than a typical DTW arrival (9.3 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 DTW. Taxi-out is gate to wheels up and sits inside the scheduled block rather than on top of it; the comparison is 9,895 departures from IAH scheduled in the clock hour DL1389 most often leaves in. Taxi-in is landing to gate, compared against every arrival FlyerIntel has on file at DTW (388,616 flights), not just DL1389’s own. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026
The hour it leaves IAH
Part of any flight’s record belongs to the clock rather than to the flight. DL1389 has one departure time, so this is what that time is worth.
On-time arrival rate. 9,895 departures from IAH are scheduled in the 5 AM–6 AM hour over the period, against 359,450 across the whole day.
DL1389 is scheduled out of IAH at 5:30 AM, in the 5 AM–6 AM bank. Departures from IAH in that hour arrive on time 90.5% of the time against 77.4% across the airport’s whole day — the slot alone is worth 13.1 points better before anything about this particular flight is considered.
The two airport figures cover every departure from IAH 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 · July 2023 – July 2026 · Hours below 120 departures are not scored.
By day of week
Does DL1389 run worse on particular days?
Tuesday is historically the most reliable day and Sunday the least, a gap of 3.9 percentage points.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Days with fewer than 120 operations are not scored.
Other routes DL1389 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 |
|---|---|---|---|
| DTW→BOS Detroit to Boston | January 8, 2024 – March 9, 2024 | 62 | — |
Because the same number has served different journeys, the statistics above describe only the route DL1389 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.
16 min late
against a median of 10 min early
Percentiles over 1,065 operations; cancelled and diverted flights are counted separately.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
Data and methodology
Calculated by FlyerIntel from 1,065 records of DL1389 operating IAH → DTW, 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
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