Flight number record

DL 512

Delta Air Lines · Atlanta to Dallas

Route: ATL → DAL
Departs: 13:59
Flights: 365
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 512, check with Delta Air Lines.

DL 512 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 9 points better than the national rate of 77.6%. When something does go wrong the average delay runs roughly 50 minutes. That rests on 365 flights, with a median arrival 10 minutes early.

Set against the rest of the country, DL 512's record is 9 points better than the US average of 77.6%. That gap is worth roughly 86 fewer late arrivals for every thousand flights.

On time

86.2%

Arrivals under 15 minutes late, of 354 completed flights

Avg delay

48 min

Across delayed arrivals only, not all flights

Cancelled

1.64%

National rate is 1.81%

1 hour+ late

4.2%

National rate is 8.1%

These figures cover 365 flights between July 2025 and June 2026. The median arrival is 10 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 512 flies

DL 512 flies ATL to DAL without a single fixed slot. Its most common scheduled departure was 13:59, used on 95 of 365 flights, with 13:56 (64 flights) and 14:06 (41 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 13:5995 flights26.0%
Departs 13:5664 flights17.5%
Departs 14:0641 flights11.2%

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 13:59 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.8%, and DL 512 runs 7 points better at 86.2%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

DL 512 next to ATL to DAL

Every carrier on ATL to DAL combined arrived on time 81.3% of the time across 3,398 flights, so DL 512 is 5 points ahead of it. Delta flew 1,850 flights on the same city pair under all its flight numbers, including this one, and those ran 84.4% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight beats by 5 points.

DL 512 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 512	365	86.2%	48 min	1.64%	A
All Delta Air Lines on ATL–DAL	1,850	84.4%	62 min	2.00%	B
All carriers on ATL–DAL	3,398	81.3%	60 min	1.85%	B
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 512 quarter by quarter

Quarter by quarter DL 512 held fairly steady: 89.9% in Jul–Sep 2025, 87.9% in Oct–Dec 2025, 81.6% in Jan–Mar 2026 and 85.1% in Apr–Jun 2026. A spread of 8 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202592 flights89.9%
Oct–Dec 202592 flights87.9%
Jan–Mar 202690 flights81.6%
Apr–Jun 202691 flights85.1%

Scale runs 75% to 95%. Rows with fewer than 30 flights show a dash.

By weekday, DL 512 did best on Thursday at 92.2% on time and worst on Tuesday at 80.0%. Each day rests on about 52 flights, so a gap of 12 points is worth noticing but could still narrow in another year.

Delay causes

Why DL 512 runs late

One category carries most of the weight here. Carrier accounts for 62% of the 2,366 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
62%
National Airspace System
20%
Late-arriving aircraft
16%
Extreme weather
1%

The largest share of delay minutes, 62%, 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 1,461 of the 2,366 delay minutes reported here. The split is drawn from 2,366 delay minutes reported on DL 512.

Cancellations sit at 1.64% against a national 1.81%, which is ordinary. Diversions add another 1.37%.

Connections and routes

What a delay on this flight costs

Badly late arrivals are rare here: only 4.2% land an hour or more behind schedule, against 8.1% 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 721 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 512 is not only a ATL to DAL flight. It also flew DAL to ATL (362 flights, 71.2% 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. 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.

Other routes flown as DL 512
Also flown as	Flights	On time	Avg delay	Cancelled	Grade
DAL to ATLthin sample	362	71.2%	68 min	1.66%	C

What to do with this

Booking DL 512

For a booking, read DL 512 as 86.2% on time with 1.64% cancelled over 365 flights. Those are rates from the past twelve months, not a forecast for any particular 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