Flight number record

DL 1557

Delta Air Lines · Detroit to Nashville

Route: DTW → BNA
Departs: 12:15
Flights: 302
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 1557, check with Delta Air Lines.

DL 1557 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 about an hour. That rests on 302 flights, with a median arrival 10 minutes early.

Set against the rest of the country, DL 1557's record is 9 points better than the US average of 77.6%. That gap is worth roughly 92 fewer late arrivals for every thousand flights.

On time

86.8%

Arrivals under 15 minutes late, of 295 completed flights

Avg delay

66 min

Across delayed arrivals only, not all flights

Cancelled

1.66%

National rate is 1.81%

1 hour+ late

5.4%

National rate is 8.1%

These figures cover 302 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 1557 flies

DL 1557 flies DTW to BNA without a single fixed slot. Its most common scheduled departure was 12:15, used on 95 of 302 flights, with 12:30 (80 flights) and 12:20 (54 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 12:1595 flights31.5%
Departs 12:3080 flights26.5%
Departs 12:2054 flights17.9%

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 12:15 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.8%, and DL 1557 runs 8 points better at 86.8%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

DL 1557 next to DTW to BNA

Every carrier on DTW to BNA combined arrived on time 78.7% of the time across 2,417 flights, so DL 1557 is 8 points ahead of it. Delta flew 1,403 flights on the same city pair under all its flight numbers, including this one, and those ran 79.5% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight beats by 5 points.

DL 1557 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 1557thin sample	302	86.8%	66 min	1.66%	A
All Delta Air Lines on DTW–BNA	1,403	79.5%	61 min	1.85%	B
All carriers on DTW–BNA	2,417	78.7%	54 min	1.37%	B
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 1557 quarter by quarter

Quarter by quarter DL 1557 held fairly steady: 90.7% in Jul–Sep 2025, 82.1% in Oct–Dec 2025, 85.4% in Jan–Mar 2026 and 88.1% in Apr–Jun 2026. A spread of 9 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202586 flights90.7%
Oct–Dec 202587 flights82.1%
Jan–Mar 202643 flights85.4%
Apr–Jun 202686 flights88.1%

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

By weekday, DL 1557 ranged from 81.4% on Sunday to 91.1% on Thursday. With about 43 flights behind each day, a spread of 10 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why DL 1557 runs late

One category carries most of the weight here. Carrier accounts for 59% of the 2,585 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
59%
Late-arriving aircraft
26%
National Airspace System
14%
Extreme weather
1%

The largest share of delay minutes, 59%, 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 1,530 of the 2,585 delay minutes reported here. The split is drawn from 2,585 delay minutes reported on DL 1557.

Cancellations sit at 1.66% against a national 1.81%, which is ordinary. Diversions add another 0.66%.

Connections and routes

What a delay on this flight costs

5.4% 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.

DL 1557 is not only a DTW to BNA flight. It also flew BNA to DTW (299 flights, 85.0% 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. 302 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 1557
Also flown as	Flights	On time	Avg delay	Cancelled	Grade
BNA to DTWthin sample	299	85.0%	102 min	1.67%	A

What to do with this

Booking DL 1557

For a booking, read DL 1557 as 86.8% on time with 1.66% cancelled over 302 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