Flight number record
DL 387
Delta Air Lines · Atlanta to Salt Lake City
- Route
- ATL → SLC
- Departs
- 10:05
- Flights
- 365
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 387, check with Delta Air Lines.
DL 387 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 13 points better than the national rate of 77.3%. When something does go wrong the average delay runs roughly 50 minutes. That rests on 365 flights, with a median arrival 8 minutes early.
Set against the rest of the country, DL 387's record is 13 points better than the US average of 77.3%. That gap is worth roughly 130 fewer late arrivals for every thousand flights.
Key figures
On time
90.3%
Arrivals under 15 minutes late, of 361 completed flights
Avg delay
48 min
Across delayed arrivals only, not all flights
Cancelled
0.55%
National rate is 1.89%
1 hour+ late
1.9%
National rate is 8.3%
These figures cover 365 flights between September 2025 and August 2026. The median arrival is 8 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 387 flies
DL 387 flies ATL to SLC without a single fixed slot. Its most common scheduled departure was 10:05, used on 112 of 365 flights, with 10:15 (40 flights) next.
- Departs 10:05112 flights30.7%
- Departs 10:1540 flights11.0%
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 10:05 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and DL 387 runs 6 points better at 90.3%. 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 387 next to ATL to SLC
Every carrier on ATL to SLC combined arrived on time 82.7% of the time across 2,965 flights, so DL 387 is 8 points ahead of it. Delta flew 2,959 flights on the same city pair under all its flight numbers, including this one, and those ran 82.7% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight beats by 9 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 387 | 365 | 90.3% | 48 min | 0.55% | A+ |
| All Delta Air Lines on ATL–SLC | 2,959 | 82.7% | 60 min | 0.44% | B+ |
| All carriers on ATL–SLC | 2,965 | 82.7% | 60 min | 0.44% | B+ |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 387 quarter by quarter
DL 387 did not run the same all year. Its best quarter was Jul–Sep 2025 at 100.0% on time and its weakest Oct–Dec 2025 at 87.9%, a swing of 12 points on roughly 73 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Jul–Sep 202530 flights100.0%
- Oct–Dec 202592 flights87.9%
- Jan–Mar 202690 flights89.7%
- Apr–Jun 202691 flights90.1%
- Jul–Sep 202662 flights90.3%
Scale runs 80% to 100%.
By weekday, DL 387 did best on Wednesday at 96.1% on time and worst on Monday at 81.1%. Each day rests on about 52 flights, so a gap of 15 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 387 runs when it is late
DL 387 often beats the schedule: 115 of 361 completed flights, 32%, arrived 15 minutes or more early. The 35 late arrivals split 14 under half an hour, 14 between 30 and 60 minutes, and 7 an hour or more.
- 15+ min early115 flights31.9%
- Within 15 min211 flights58.4%
- 15–29 min late14 flights3.9%
- 30–59 min late14 flights3.9%
- 1–2 hours late4 flights1.1%
- 2+ hours late3 flights0.8%
Scale runs 0% to 100%.
Share of 361 completed flights by arrival against schedule.
A late pushback is often recovered here: of 46 departures that left 15 minutes late or more, 19 still arrived on time. 8 flights left on time and still arrived late.
The worst days
Worst days for DL 387
The latest arrival of the period was on 10 November 2025, 2 hours 35 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 10 November 2025 | 2 hours 35 minutes | Carrier |
| 8 June 2026 | 2 hours 29 minutes | Carrier |
| 7 March 2026 | 2 hours 4 minutes | Carrier |
| 16 March 2026 | 1 hour 40 minutes | Late-arriving aircraft |
| 29 January 2026 | 1 hour 39 minutes | Carrier |
Delay causes
Why DL 387 runs late
Carrier accounts for 81% of the 1,678 delay minutes carriers reported here, and the remaining four split what is left.
- 81%Carrier
- 13%National Airspace System
- 6%Late-arriving aircraft
- 1%Extreme weather
The largest share of delay minutes, 81%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,361 of the 1,678 delay minutes reported here. The split is drawn from 1,678 delay minutes reported on DL 387.
Cancellations are rare at 0.55%, below the national 1.89% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and routes
What a delay on this flight costs
Badly late arrivals are rare here: only 1.9% 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.
At 1,590 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
Every one of the 365 flights under DL 387 in the data flew ATL to SLC. The number was not reused on any other city pair, which makes this a clean record of one route.
One caution: this is a thin sample. 365 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 387
For a booking, DL 387 has one of the better records a US domestic flight can show: 90.3% on time and 0.55% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- ATL to SLC, every carrier and departure
- SLC to ATL, the return direction
- Delta Air Lines 663 on the same route87.9%
- Delta Air Lines 830 on the same route87.8%
- Delta Air Lines 423 on the same route85.6%
- Delta Air Lines 653 on the same route79.4%
- Delta Air Lines 526 on the same route79.6%
- Delta Air Lines 660 on the same route75.0%
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Salt Lake City International (SLC) 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
- Worst months to fly in the US, ranked by the data
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.