Flight number record
DL 863
Delta Air Lines · New York to Salt Lake City
- Route
- JFK → SLC
- Departs
- 18:40
- Flights
- 329
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 863, check with Delta Air Lines.
DL 863 sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.3%. The late ones land about an hour behind schedule. That rests on 329 flights, with a median arrival 2 minutes early.
The national on-time rate over the same period is 77.3%, so DL 863 runs 7 points behind the country as a whole. Across a thousand flights that is about 71 extra late arrivals.
Key figures
On time
70.2%
Arrivals under 15 minutes late, of 322 completed flights
Avg delay
61 min
Across delayed arrivals only, not all flights
Cancelled
2.13%
National rate is 1.89%
1 hour+ late
10.2%
National rate is 8.3%
These figures cover 329 flights between September 2025 and August 2026. Beyond the headline rate, 10.2% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When DL 863 flies
DL 863 flies JFK to SLC without a single fixed slot. Its most common scheduled departure was 18:40, used on 109 of 329 flights, with 18:41 (62 flights) and 18:45 (56 flights) next.
- Departs 18:40109 flights33.1%
- Departs 18:4162 flights18.8%
- Departs 18:4556 flights17.0%
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 18:40 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.0%, and DL 863 runs 2 points better at 70.2%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
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Against the route
DL 863 next to JFK to SLC
Every carrier on JFK to SLC combined arrived on time 76.4% of the time across 1,929 flights, so DL 863 is 6 points behind it. Delta flew 1,536 flights on the same city pair under all its flight numbers, including this one, and those ran 78.6% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight trails by 11 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 863thin sample | 329 | 70.2% | 61 min | 2.13% | C |
| All Delta Air Lines on JFK–SLC | 1,536 | 78.6% | 66 min | 1.95% | B |
| All carriers on JFK–SLC | 1,929 | 76.4% | 65 min | 2.44% | B |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 863 quarter by quarter
DL 863 did not run the same all year. Its best quarter was Jul–Sep 2025 at 83.3% on time and its weakest Jul–Sep 2026 at 61.0%, a swing of 22 points on roughly 66 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 flights83.3%
- Oct–Dec 202560 flights73.3%
- Jan–Mar 202686 flights69.5%
- Apr–Jun 202691 flights70.3%
- Jul–Sep 202662 flights61.0%
Scale runs 55% to 90%.
By weekday, DL 863 did best on Saturday at 80.4% on time and worst on Friday at 60.9%. Each day rests on about 47 flights, so a gap of 20 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 863 runs when it is late
DL 863 often beats the schedule: 104 of 322 completed flights, 32%, arrived 15 minutes or more early. The 96 late arrivals split 28 under half an hour, 35 between 30 and 60 minutes, and 33 an hour or more.
- 15+ min early104 flights32.3%
- Within 15 min122 flights37.9%
- 15–29 min late28 flights8.7%
- 30–59 min late35 flights10.9%
- 1–2 hours late22 flights6.8%
- 2+ hours late11 flights3.4%
Scale runs 0% to 100%.
Share of 322 completed flights by arrival against schedule.
19 of 83 late departures made up the time and arrived on time, 23% of them. In the other direction, 32 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at SLC.
The worst days
Worst days for DL 863
The latest arrival of the period was on 8 November 2025, 4 hours 4 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). On four of the five worst days the largest share was filed as national airspace system delay.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 8 November 2025 | 4 hours 4 minutes | Carrier |
| 6 June 2026 | 4 hours 4 minutes | National Airspace System |
| 28 August 2026 | 3 hours 28 minutes | National Airspace System |
| 25 February 2026 | 3 hours 20 minutes | National Airspace System |
| 6 August 2026 | 3 hours 1 minute | National Airspace System |
Delay causes
Why DL 863 runs late
National Airspace System accounts for 51% of the 5,874 delay minutes carriers reported here, and the remaining four split what is left.
- 51%National Airspace System
- 33%Carrier
- 14%Late-arriving aircraft
- 1%Extreme weather
51% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 3,007 minutes out of 5,874, against a national NAS share of 21%. The split is drawn from 5,874 delay minutes reported on DL 863.
Cancellations sit at 2.13% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
10.2% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
At 1,990 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.
The same number turns up on one other city pair in the data, including OGG to SLC (17), but none flew often enough under DL 863 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to JFK to SLC only.
One caution: this is a thin sample. 329 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 863
For a booking, DL 863 is one of the weaker ways to fly JFK to SLC: 6 points below the route as a whole. If the schedule allows, compare it with the other departures listed on the route page before settling on this one.
Related
Where to go next
- JFK to SLC, every carrier and departure
- SLC to JFK, the return direction
- Delta Air Lines 887 on the same route76.8%
- Delta Air Lines 892 on the same route87.1%
- Delta Air Lines 917 on the same route79.8%
- JetBlue Airways 71 on the same route69.6%
- John F. Kennedy International (JFK) 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
- How often a connection fails at the major US hubs
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.