Flight number record

DL 507

Delta Air Lines · Los Angeles to Boston

Route: LAX → BOS
Departs: 21:00
Flights: 278
Period: July 2025 to June 2026

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

DL 507 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 8 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 278 flights, with a median arrival 6 minutes early.

Set against the rest of the country, DL 507's record is 8 points better than the US average of 77.6%. That gap is worth roughly 80 fewer late arrivals for every thousand flights.

On time

85.6%

Arrivals under 15 minutes late, of 270 completed flights

Avg delay

76 min

Across delayed arrivals only, not all flights

Cancelled

2.88%

National rate is 1.81%

1 hour+ late

5.2%

National rate is 8.1%

These figures cover 278 flights between July 2025 and June 2026. The median arrival is 6 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 507 flies

DL 507 flies LAX to BOS without a single fixed slot. Its most common scheduled departure was 21:00, used on 113 of 278 flights, with 21:15 (30 flights) and 21:45 (28 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 21:00113 flights40.6%
Departs 21:1530 flights10.8%
Departs 21:4528 flights10.1%

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 21:00 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.5%, and DL 507 runs 15 points better at 85.6%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.

Against the route

DL 507 next to LAX to BOS

Every carrier on LAX to BOS combined arrived on time 78.4% of the time across 4,718 flights, so DL 507 is 7 points ahead of it. Delta flew 1,230 flights on the same city pair under all its flight numbers, including this one, and those ran 78.6% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight beats by 4 points.

DL 507 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 507thin sample	278	85.6%	76 min	2.88%	A
All Delta Air Lines on LAX–BOS	1,230	78.6%	86 min	1.71%	B
All carriers on LAX–BOS	4,718	78.4%	81 min	1.42%	B
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	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 70 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 202553 flights90.6%
Oct–Dec 202572 flights91.3%
Jan–Mar 202672 flights79.4%
Apr–Jun 202681 flights82.5%

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

By weekday, DL 507 did best on Friday at 97.7% on time and worst on Tuesday at 77.5%. Each day rests on about 40 flights, so a gap of 20 points is worth noticing but could still narrow in another year.

Delay causes

Why DL 507 runs late

One category carries most of the weight here. Carrier accounts for 71% of the 2,952 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
71%
Late-arriving aircraft
17%
National Airspace System
12%

The largest share of delay minutes, 71%, 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 2,090 of the 2,952 delay minutes reported here. The split is drawn from 2,952 delay minutes reported on DL 507.

Cancellations run at 2.88%, against 1.81% nationally. That is roughly one flight in 30 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

5.2% 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.

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.

The same number turns up on two other city pairs in the data, including LAS to SEA (9) and SAT to ATL (1), but none flew often enough under DL 507 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to LAX to BOS only.

One caution: this is a thin sample. 278 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: 2.88% of its 278 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures