Flight number record

DL 1738

Delta Air Lines · Salt Lake City to Phoenix

Route: SLC → PHX
Departs: 15:28
Flights: 319
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 1738, check with Delta Air Lines.

DL 1738 earns an A+. 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 77.6%. When something does go wrong the average delay runs a little over 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 77.6%. That gap is worth roughly 74 fewer late arrivals for every thousand flights.

On time

85.0%

Arrivals under 15 minutes late, of 319 completed flights

Avg delay

71 min

Across delayed arrivals only, not all flights

Cancelled

0.00%

National rate is 1.81%

1 hour+ late

5.6%

National rate is 8.1%

These figures cover 319 flights between July 2025 and June 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.

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 15:31 (56 flights) and 15:20 (42 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 15:28100 flights31.3%
Departs 15:3156 flights17.6%
Departs 15:2042 flights13.2%

Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.

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 72.4%, and DL 1738 runs 13 points better at 85.0%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

DL 1738 next to SLC to PHX

Every carrier on SLC to PHX combined arrived on time 83.9% of the time across 5,759 flights, so DL 1738 is about level with it. Delta flew 1,708 flights on the same city pair under all its flight numbers, including this one, and those ran 87.9% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight beats by 3 points.

DL 1738 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 1738thin sample	319	85.0%	71 min	0.00%	A+
All Delta Air Lines on SLC–PHX	1,708	87.9%	56 min	0.53%	A+
All carriers on SLC–PHX	5,759	83.9%	71 min	0.56%	B+
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 1738 quarter by quarter

DL 1738 did not run the same all year. Its best quarter was Apr–Jun 2026 at 91.2% on time and its weakest Oct–Dec 2025 at 71.2%, a swing of 20 points on roughly 80 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 202592 flights88.0%
Oct–Dec 202580 flights71.2%
Jan–Mar 202656 flights89.3%
Apr–Jun 202691 flights91.2%

Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.

By weekday, DL 1738 ranged from 80.4% on Thursday to 91.7% on Tuesday. With about 46 flights behind each day, a spread of 11 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why DL 1738 runs late

One category carries most of the weight here. Carrier accounts for 54% of the 3,425 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

Carrier
54%
Late-arriving aircraft
30%
National Airspace System
15%
Extreme weather
1%

The largest share of delay minutes, 54%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 1,833 of the 3,425 delay minutes reported here. The split is drawn from 3,425 delay minutes reported on DL 1738.

Cancellations are rare at 0.00%, below the national 1.81% 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

5.6% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last a little over an hour, which a normal layover absorbs.

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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.

DL 1738 is not only a SLC to PHX flight. It also flew PHX to SLC (258 flights, 88.0% 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.

Other routes flown as DL 1738
Also flown as	Flights	On time	Avg delay	Cancelled	Grade
PHX to SLCthin sample	258	88.0%	69 min	0.00%	A+

What to do with this

Booking DL 1738

For a booking, DL 1738 has one of the better records a US domestic flight can show: 85.0% on time and 0.00% cancelled. That is a base rate, not a promise about any single day.

Where to go next

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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures