Flight number record

B6 451

JetBlue Airways · Boston to Orlando

Route: BOS → MCO
Departs: 16:20
Flights: 361
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s B6 451, check with JetBlue Airways.

B6 451 earns an F, which is as low as this site's scale goes for a reason. Only 51.3% of flights arrive inside the 15-minute window, 26 points worse than the national rate of 77.6%. Late arrivals average a little over an hour. Treat any tight connection here as a coin flip. That rests on 361 flights, with a median arrival 13 minutes late.

The national on-time rate over the same period is 77.6%, so B6 451 runs 26 points behind the country as a whole. Across a thousand flights that is about 263 extra late arrivals.

On time

51.3%

Arrivals under 15 minutes late, of 347 completed flights

Avg delay

79 min

Across delayed arrivals only, not all flights

Cancelled

2.49%

National rate is 1.81%

1 hour+ late

21.6%

National rate is 8.1%

These figures cover 361 flights between July 2025 and June 2026. Beyond the headline rate, 21.6% 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 B6 451 flies

B6 451 flies BOS to MCO without a single fixed slot. Its most common scheduled departure was 16:20, used on 109 of 361 flights, with 16:50 (44 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 16:20109 flights30.2%
Departs 16:5044 flights12.2%

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 16:20 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 72.4%, and B6 451 runs 21 points worse at 51.3%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

B6 451 next to BOS to MCO

Every carrier on BOS to MCO combined arrived on time 70.1% of the time across 4,606 flights, so B6 451 is 19 points behind it. JetBlue flew 2,493 flights on the same city pair under all its flight numbers, including this one, and those ran 67.9% on time. Across its whole network JetBlue Airways managed 72.7%, which this flight trails by 21 points.

B6 451 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
B6 451thin sample	361	51.3%	79 min	2.49%	F
All JetBlue Airways on BOS–MCO	2,493	67.9%	73 min	2.89%	C
All carriers on BOS–MCO	4,606	70.1%	77 min	2.74%	C
JetBlue Airways, whole network	234,468	72.7%	76 min	2.56%	C

Across the year

B6 451 quarter by quarter

B6 451 did not run the same all year. Its best quarter was Jan–Mar 2026 at 57.8% on time and its weakest Jul–Sep 2025 at 41.4%, a swing of 16 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 202592 flights41.4%
Oct–Dec 202592 flights48.9%
Jan–Mar 202689 flights57.8%
Apr–Jun 202688 flights57.5%

Scale runs 35% to 65%. Rows with fewer than 30 flights show a dash.

By weekday, B6 451 did best on Wednesday at 66.0% on time and worst on Sunday at 36.7%. Each day rests on about 52 flights, so a gap of 29 points is worth noticing but could still narrow in another year.

Delay causes

Why B6 451 runs late

One category carries most of the weight here. Late-arriving aircraft accounts for 49% of the 13,000 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.

Late-arriving aircraft
49%
National Airspace System
30%
Carrier
19%
Extreme weather
2%
Security
0%

49% 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 13,000 reported delay minutes here, that single category outweighs weather by 27 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 13,282 delay minutes reported on B6 451.

Cancellations sit at 2.49% against a national 1.81%, which is ordinary. Diversions add another 1.39%.

Connections and routes

What a delay on this flight costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 21.6% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.

The 1,121 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.

Every one of the 361 flights under B6 451 in the data flew BOS to MCO. 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. 361 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 B6 451

For a booking, B6 451 is a flight to put a long connection behind. 21.6% of its completed flights arrived an hour or more late, which a short layover will not absorb. If the onward flight is on a separate ticket, the risk sits with you.

Where to go next

A flight number here means JetBlue Airways’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