Flight number record

DL 507

Delta Air Lines · Los Angeles to Boston

Route: LAX → BOS
Departs: 21:00
Flights: 295
Period: September 2025 to August 2026

Historical statistics for September 2025 to August 2026, not live status. For today’s DL 507, check with Delta Air Lines.

DL 507 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 a little over an hour. That rests on 295 flights, with a median arrival 5 minutes early.

Set against the rest of the country, DL 507's record is 7 points better than the US average of 77.3%. That gap is worth roughly 67 fewer late arrivals for every thousand flights.

On time

84.0%

Arrivals under 15 minutes late, of 287 completed flights

Avg delay

73 min

Across delayed arrivals only, not all flights

Cancelled

2.71%

National rate is 1.89%

1 hour+ late

5.6%

National rate is 8.3%

These figures cover 295 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 507 flies

DL 507 flies LAX to BOS without a single fixed slot. Its most common scheduled departure was 21:00, used on 156 of 295 flights, with 21:15 (30 flights) next.

Departs 21:00156 flights52.9%
Departs 21:1530 flights10.2%

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 21:00 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.1%, and DL 507 runs 14 points better at 84.0%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.

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Against the route

DL 507 next to LAX to BOS

Every carrier on LAX to BOS combined arrived on time 76.2% of the time across 4,797 flights, so DL 507 is 8 points ahead of it. Delta flew 1,240 flights on the same city pair under all its flight numbers, including this one, and those ran 75.9% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight beats by 3 points.

DL 507 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 507thin sample	295	84.0%	73 min	2.71%	B
All Delta Air Lines on LAX–BOS	1,240	75.9%	89 min	2.18%	B
All carriers on LAX–BOS	4,797	76.2%	80 min	1.81%	B
Delta Air Lines, whole network	1,039,517	81.1%	71 min	1.74%	B

Across the year

DL 507 quarter by quarter

DL 507 did not run the same all year. Its best quarter was Oct–Dec 2025 at 91.3% on time and its weakest Jan–Mar 2026 at 79.4%, a swing of 12 points on roughly 74 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 202517 flights—
Oct–Dec 202572 flights91.3%
Jan–Mar 202672 flights79.4%
Apr–Jun 202681 flights82.5%
Jul–Sep 202653 flights81.1%

Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.

By weekday, DL 507 did best on Friday at 97.8% on time and worst on Monday at 71.7%. Each day rests on about 42 flights, so a gap of 26 points is worth noticing but could still narrow in another year.

Arrival by arrival

How late DL 507 runs when it is late

DL 507 often beats the schedule: 89 of 287 completed flights, 31%, arrived 15 minutes or more early. The 46 late arrivals split 18 under half an hour, 12 between 30 and 60 minutes, and 16 an hour or more.

15+ min early89 flights31.0%
Within 15 min152 flights53.0%
15–29 min late18 flights6.3%
30–59 min late12 flights4.2%
1–2 hours late10 flights3.5%
2+ hours late6 flights2.1%

Scale runs 0% to 100%.

Share of 287 completed flights by arrival against schedule.

A late pushback is often recovered here: of 46 departures that left 15 minutes late or more, 15 still arrived on time. In the other direction, 15 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at BOS.

The worst days

Worst days for DL 507

The latest arrival of the period was on 7 January 2026, 13 hours 12 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.

The latest arrivals of DL 507 in the period
Date	Arrived late by	Largest filed cause
7 January 2026	13 hours 12 minutes	Carrier
14 June 2026	3 hours 52 minutes	Late-arriving aircraft
27 January 2026	2 hours 44 minutes	Carrier
14 July 2026	2 hours 33 minutes	Late-arriving aircraft
24 February 2026	2 hours 27 minutes	Carrier

Delay causes

Why DL 507 runs late

Carrier accounts for 65% of the 3,345 delay minutes carriers reported here, and the remaining four split what is left.

Carrier
65%
Late-arriving aircraft
23%
National Airspace System
12%

The largest share of delay minutes, 65%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 2,178 of the 3,345 delay minutes reported here. The split is drawn from 3,345 delay minutes reported on DL 507.

Cancellations run at 2.71%, against 1.89% nationally. That is about one flight in 40 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.

Connections and routes

What a delay on this flight costs

5.6% of arrivals land an hour or more late, close to the national 8.3%, so 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.

At 2,611 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.

Every one of the 295 flights under DL 507 in the data flew LAX to BOS. The number was not reused on any other city pair, which makes this a clean record of one route.

One caution: this is a thin sample. 295 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 507

For a booking, the cancellation rate is the figure to plan around on DL 507: 2.71% of its 295 scheduled flights did not operate. A late arrival costs a little over an hour, but a cancellation costs the day, so leave a later option open.

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, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures