Flight number record
DL 1738
Delta Air Lines · Salt Lake City to Phoenix
- Route
- SLC → PHX
- Departs
- 15:28
- Flights
- 319
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 1738, check with Delta Air Lines.
DL 1738 earns a B+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.3%. When something does go wrong the average delay runs about an hour. That rests on 319 flights, with a median arrival 5 minutes early.
Set against the rest of the country, DL 1738's record is 7 points better than the US average of 77.3%. That gap is worth roughly 73 fewer late arrivals for every thousand flights.
Key figures
On time
84.6%
Arrivals under 15 minutes late, of 319 completed flights
Avg delay
66 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.89%
1 hour+ late
4.4%
National rate is 8.3%
These figures cover 319 flights between September 2025 and August 2026. The median arrival is 5 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 1738 flies
DL 1738 flies SLC to PHX without a single fixed slot. Its most common scheduled departure was 15:28, used on 100 of 319 flights, with 15:20 (67 flights) and 15:31 (35 flights) next.
- Departs 15:28100 flights31.3%
- Departs 15:2067 flights21.0%
- Departs 15:3135 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 15:28 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 71.9%, and DL 1738 runs 13 points better at 84.6%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
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Against the route
DL 1738 next to SLC to PHX
Every carrier on SLC to PHX combined arrived on time 83.5% of the time across 5,778 flights, so DL 1738 is about level with it. Delta flew 1,707 flights on the same city pair under all its flight numbers, including this one, and those ran 87.6% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight beats by 4 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 1738thin sample | 319 | 84.6% | 66 min | 0.00% | B+ |
| All Delta Air Lines on SLC–PHX | 1,707 | 87.6% | 56 min | 0.53% | A+ |
| All carriers on SLC–PHX | 5,778 | 83.5% | 70 min | 0.54% | B+ |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 1738 quarter by quarter
DL 1738 did not run the same all year. Its best quarter was Jul–Sep 2025 at 93.3% on time and its weakest Oct–Dec 2025 at 71.2%, a swing of 22 points on roughly 64 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 flights93.3%
- Oct–Dec 202580 flights71.2%
- Jan–Mar 202656 flights89.3%
- Apr–Jun 202691 flights91.2%
- Jul–Sep 202662 flights83.9%
Scale runs 65% to 100%.
By weekday, DL 1738 did best on Tuesday at 91.5% on time and worst on Friday at 78.3%. Each day rests on about 46 flights, so a gap of 13 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 1738 runs when it is late
The 49 late arrivals split 23 under half an hour, 12 between 30 and 60 minutes, and 14 an hour or more.
- 15+ min early44 flights13.8%
- Within 15 min226 flights70.8%
- 15–29 min late23 flights7.2%
- 30–59 min late12 flights3.8%
- 1–2 hours late6 flights1.9%
- 2+ hours late8 flights2.5%
Scale runs 0% to 100%.
Share of 319 completed flights by arrival against schedule.
11 of 50 late departures made up the time and arrived on time, 22% of them. 10 flights left on time and still arrived late.
The worst days
Worst days for DL 1738
The latest arrival of the period was on 30 November 2025, 6 hours 2 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. Three of the five worst days fell in November 2025.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 30 November 2025 | 6 hours 2 minutes | Late-arriving aircraft |
| 26 September 2025 | 4 hours 12 minutes | National Airspace System |
| 5 November 2025 | 4 hours 9 minutes | Late-arriving aircraft |
| 19 November 2025 | 3 hours 42 minutes | Carrier |
| 14 December 2025 | 3 hours 15 minutes | Carrier |
Delay causes
Why DL 1738 runs late
Carrier accounts for 49% of the 3,229 delay minutes carriers reported here, and the remaining four split what is left.
- 49%Carrier
- 30%Late-arriving aircraft
- 19%National Airspace System
- 1%Extreme weather
The largest share of delay minutes, 49%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,594 of the 3,229 delay minutes reported here. The split is drawn from 3,229 delay minutes reported on DL 1738.
Cancellations are rare at 0.00%, below the national 1.89% and low enough to earn the plus on the grade. Almost no flights are 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 4.4% 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 507 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.
DL 1738 is not only a SLC to PHX flight. It also flew PHX to SLC (258 flights, 86.4% on time) often enough to be scored on its own. Airlines attach one number to several legs of an aircraft's day, and each leg keeps its own record here, so check which city pair is on your booking before reading a rate.
One caution: this is a thin sample. 319 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.
| Also flown as | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| PHX to SLCthin sample | 258 | 86.4% | 93 min | 0.00% | A+ |
What to do with this
Booking DL 1738
For a booking, read DL 1738 as 84.6% on time with 0.00% cancelled over 319 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- SLC to PHX, every carrier and departure
- PHX to SLC, the return direction
- SkyWest Airlines 6327 on the same route89.3%
- Delta Air Lines 1431 on the same route84.6%
- Delta Air Lines 1447 on the same route94.7%
- Delta Air Lines 1496 on the same route87.1%
- Salt Lake City International (SLC) delay statistics
- Phoenix Sky Harbor International (PHX) 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.