Flight number record

DL 514

Delta Air Lines · Boston to Phoenix

Route: BOS → PHX
Departs: 17:55
Flights: 358
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 514, check with Delta Air Lines.

DL 514 sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 9 points worse than the national rate of 77.6%. The late ones land roughly 55 minutes behind schedule. That rests on 358 flights, with a median arrival 1 minute late.

The national on-time rate over the same period is 77.6%, so DL 514 runs 9 points behind the country as a whole. Across a thousand flights that is about 93 extra late arrivals.

On time

68.3%

Arrivals under 15 minutes late, of 350 completed flights

Avg delay

54 min

Across delayed arrivals only, not all flights

Cancelled

1.40%

National rate is 1.81%

1 hour+ late

8.0%

National rate is 8.1%

These figures cover 358 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 514 flies

DL 514 flies BOS to PHX without a single fixed slot. Its most common scheduled departure was 17:55, used on 55 of 358 flights, with 08:10 (52 flights) and 18:50 (45 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 17:5555 flights15.4%
Departs 08:1052 flights14.5%
Departs 18:5045 flights12.6%

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 17:55 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and DL 514 runs level with that at 68.3%. 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 514 next to BOS to PHX

Every carrier on BOS to PHX combined arrived on time 76.7% of the time across 2,024 flights, so DL 514 is 8 points behind it. Across its whole network Delta Air Lines managed 81.6%, which this flight trails by 13 points.

DL 514 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 514thin sample	358	68.3%	54 min	1.40%	C
All Delta Air Lines on BOS–PHX	428	69.1%	57 min	1.87%	C
All carriers on BOS–PHX	2,024	76.7%	70 min	1.73%	B
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 514 quarter by quarter

DL 514 did not run the same all year. Its best quarter was Jan–Mar 2026 at 79.1% on time and its weakest Jul–Sep 2025 at 56.5%, a swing of 23 points on roughly 90 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 202590 flights56.5%
Oct–Dec 202588 flights59.1%
Jan–Mar 202689 flights79.1%
Apr–Jun 202691 flights78.0%

Scale runs 50% to 85%. Rows with fewer than 30 flights show a dash.

By weekday, DL 514 ranged from 62.0% on Friday to 72.9% on Wednesday. With about 51 flights behind each day, a spread of 11 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why DL 514 runs late

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 5,966 reported delay minutes.

National Airspace System
35%
Late-arriving aircraft
35%
Carrier
24%
Extreme weather
6%

35% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 5,966 reported delay minutes here, that single category outweighs weather by 6 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 5,966 delay minutes reported on DL 514.

Cancellations sit at 1.40% against a national 1.81%, which is ordinary. Diversions add another 0.84%.

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 roughly 55 minutes, which a normal layover absorbs.

At 2,300 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 PHX to BOS (190) and RDU to BOS (1), but none flew often enough under DL 514 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to BOS to PHX only.

One caution: this is a thin sample. 358 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 514

For a booking, DL 514 is one of the weaker ways to fly BOS to PHX: 8 points below the route as a whole. If the schedule allows, compare it with the other departures listed on the route page before settling on this one.

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