Flight number record
DL 1639
Delta Air Lines · Charlotte to Detroit
- Route
- CLT → DTW
- Departs
- 09:42
- Flights
- 271
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 1639, check with Delta Air Lines.
DL 1639 earns an A. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 14 points better than the national rate of 77.3%. When something does go wrong the average delay runs an hour and a half. That rests on 271 flights, with a median arrival 17 minutes early.
Set against the rest of the country, DL 1639's record is 14 points better than the US average of 77.3%. That gap is worth roughly 137 fewer late arrivals for every thousand flights.
Key figures
On time
91.0%
Arrivals under 15 minutes late, of 267 completed flights
Avg delay
93 min
Across delayed arrivals only, not all flights
Cancelled
1.11%
National rate is 1.89%
1 hour+ late
3.0%
National rate is 8.3%
These figures cover 271 flights between September 2025 and August 2026. The median arrival is 17 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
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Schedule
When DL 1639 flies
DL 1639 flies CLT to DTW without a single fixed slot. Its most common scheduled departure was 09:42, used on 43 of 271 flights, with 09:38 (31 flights) and 09:32 (29 flights) next.
- Departs 09:4243 flights15.9%
- Departs 09:3831 flights11.4%
- Departs 09:3229 flights10.7%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 09:42 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and DL 1639 runs 7 points better at 91.0%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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Against the route
DL 1639 next to CLT to DTW
Every carrier on CLT to DTW combined arrived on time 81.7% of the time across 3,475 flights, so DL 1639 is 9 points ahead of it. Delta flew 1,341 flights on the same city pair under all its flight numbers, including this one, and those ran 86.3% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight beats by 10 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 1639thin sample | 271 | 91.0% | 93 min | 1.11% | A |
| All Delta Air Lines on CLT–DTW | 1,341 | 86.3% | 84 min | 1.57% | A |
| All carriers on CLT–DTW | 3,475 | 81.7% | 78 min | 1.76% | B |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 1639 quarter by quarter
Quarter by quarter DL 1639 held fairly steady: 89.6% in Oct–Dec 2025, 92.3% in Jan–Mar 2026, 91.7% in Apr–Jun 2026 and 87.8% in Jul–Sep 2026. A spread of 5 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 202526 flights—
- Oct–Dec 202568 flights89.6%
- Jan–Mar 202679 flights92.3%
- Apr–Jun 202649 flights91.7%
- Jul–Sep 202649 flights87.8%
Scale runs 80% to 100%. Rows with fewer than 30 flights show a dash.
By weekday, DL 1639 ranged from 88.4% on Monday to 93.0% on Thursday. With about 39 flights behind each day, a spread of 5 points is inside normal variation, so the day you fly is not worth changing for this flight.
Arrival by arrival
How late DL 1639 runs when it is late
DL 1639 often beats the schedule: 154 of 267 completed flights, 58%, arrived 15 minutes or more early. The 24 late arrivals split 10 under half an hour, 6 between 30 and 60 minutes, and 8 an hour or more.
- 15+ min early154 flights57.7%
- Within 15 min89 flights33.3%
- 15–29 min late10 flights3.7%
- 30–59 min late6 flights2.2%
- 1–2 hours late5 flights1.9%
- 2+ hours late3 flights1.1%
Scale runs 0% to 100%.
Share of 267 completed flights by arrival against schedule.
5 of 25 late departures made up the time and arrived on time, 20% of them. Only 4 left on time and still arrived late.
The worst days
Worst days for DL 1639
The latest arrival of the period was on 30 July 2026, 11 hours 28 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). Three of the five worst days fell in March 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 30 July 2026 | 11 hours 28 minutes | Carrier |
| 16 March 2026 | 6 hours 7 minutes | Late-arriving aircraft |
| 25 March 2026 | 4 hours 37 minutes | Carrier |
| 15 April 2026 | 1 hour 59 minutes | Late-arriving aircraft |
| 17 March 2026 | 1 hour 48 minutes | Late-arriving aircraft |
Delay causes
Why DL 1639 runs late
Carrier accounts for 50% of the 2,222 delay minutes carriers reported here, and the remaining four split what is left.
- 50%Carrier
- 43%Late-arriving aircraft
- 7%National Airspace System
43% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 2,222 reported delay minutes here, that single category outweighs weather by 43 to one. The split is drawn from 2,222 delay minutes reported on DL 1639.
Cancellations sit at 1.11% against a national 1.89%, which is ordinary. Diversions add another 0.37%.
Connections and routes
What a delay on this flight costs
Badly late arrivals are rare here: only 3.0% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
The 500 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
The same number turns up on one other city pair in the data, including MSY to LGA (12), but none flew often enough under DL 1639 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to CLT to DTW only.
One caution: this is a thin sample. 271 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking DL 1639
For a booking, DL 1639 has one of the better records a US domestic flight can show: 91.0% on time and 1.11% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- CLT to DTW, every carrier and departure
- DTW to CLT, the return direction
- Delta Air Lines 1405 on the same route93.8%
- Charlotte Douglas International (CLT) delay statistics
- Detroit Metropolitan Wayne County (DTW) delay statistics
- Delta Air Lines on-time record
- Every Delta Air Lines flight number with a record
- The most and least reliable flight numbers in the US
- Why the first flight of the morning is statistically safest
A flight number here means Delta Air Lines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.