Flight number record

DL 1243

Delta Air Lines · Detroit to Tampa

Route: DTW → TPA
Departs: 15:55
Flights: 319
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 1243, check with Delta Air Lines.

DL 1243 lands a B, 5 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 319 flights, with a median arrival 4 minutes early.

Set against the rest of the country, DL 1243's record is 5 points better than the US average of 77.6%. That gap is worth roughly 51 fewer late arrivals for every thousand flights.

On time

82.7%

Arrivals under 15 minutes late, of 312 completed flights

Avg delay

65 min

Across delayed arrivals only, not all flights

Cancelled

1.88%

National rate is 1.81%

1 hour+ late

8.0%

National rate is 8.1%

These figures cover 319 flights between July 2025 and June 2026. Beyond the headline rate, 8.0% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Schedule

When DL 1243 flies

DL 1243 flies DTW to TPA without a single fixed slot. Its most common scheduled departure was 15:55, used on 38 of 319 flights, with 14:19 (36 flights) and 14:24 (36 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 15:5538 flights11.9%
Departs 14:1936 flights11.3%
Departs 14:2436 flights11.3%

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 15:55 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 72.4%, and DL 1243 runs 10 points better at 82.7%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

DL 1243 next to DTW to TPA

Every carrier on DTW to TPA combined arrived on time 79.0% of the time across 2,370 flights, so DL 1243 is 4 points ahead of it. Delta flew 1,716 flights on the same city pair under all its flight numbers, including this one, and those ran 80.9% on time. Across its whole network Delta Air Lines managed 81.6%, close to this flight's figure.

DL 1243 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 1243thin sample	319	82.7%	65 min	1.88%	B
All Delta Air Lines on DTW–TPA	1,716	80.9%	61 min	1.34%	B
All carriers on DTW–TPA	2,370	79.0%	61 min	1.86%	B
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 1243 quarter by quarter

Quarter by quarter DL 1243 held fairly steady: 86.2% in Jul–Sep 2025, 81.4% in Oct–Dec 2025, 80.7% in Jan–Mar 2026 and 82.2% in Apr–Jun 2026. A spread of 6 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202582 flights86.2%
Oct–Dec 202560 flights81.4%
Jan–Mar 202686 flights80.7%
Apr–Jun 202691 flights82.2%

Scale runs 70% to 90%. Rows with fewer than 30 flights show a dash.

By weekday, DL 1243 did best on Wednesday at 88.4% on time and worst on Sunday at 75.6%. Each day rests on about 46 flights, so a gap of 13 points is worth noticing but could still narrow in another year.

Delay causes

Why DL 1243 runs late

One category carries most of the weight here. Carrier accounts for 46% of the 3,495 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
46%
National Airspace System
28%
Late-arriving aircraft
24%
Extreme weather
2%

The largest share of delay minutes, 46%, 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 1,613 of the 3,495 delay minutes reported here. The split is drawn from 3,495 delay minutes reported on DL 1243.

Cancellations sit at 1.88% against a national 1.81%, which is ordinary. Diversions add another 0.31%.

Connections and routes

What a delay on this flight costs

8.0% 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 about an hour, which a normal layover absorbs.

The 983 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.

The same number turns up on two other city pairs in the data, including TPA to DTW (165) and JAX to LGA (16), but none flew often enough under DL 1243 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to DTW to TPA only.

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.

What to do with this

Booking DL 1243

For a booking, read DL 1243 as 82.7% on time with 1.88% cancelled over 319 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