Flight profile · JetBlue
B61734
San Francisco (SFO) to Boston (BOS) · scheduled 12:20 PM – 5:14 PM
How B61734 performs
1,055 operations, July 2023 – July 2026.
B61734 arrived on time 74.9% of the time, against 77.9% for all SFO → BOS flights, so this departure is 3.0 percentage points worse than the route as a whole. Against JetBlue’s own flights on this route it is 1.2 points worse.
Source: US DOT Bureau of Transportation Statistics · 1,055 operations, July 2023 – July 2026 · If B61734 is cancelled or significantly changed, DOT’s automatic refund rule may entitle you to your money back. The refund checker walks through eligibility.
What stands out
How B61734 compares to other flight numbers, not just to itself.
Which day you fly matters unusually much here, a wider weekday spread than 90% of 1,710 comparable flight numbers.
81.2% on time on a typical Tuesday, against 63.9% on a Monday.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · The one thing about this specific departure that ranks most extreme against every other published flight number, out of everything FlyerIntel checks — shown only when something clears a real statistical bar, not for every flight.
Where B61734 is right now
A live reading, only if you ask for it. It is not part of the reliability record above.
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Against the rest of the route
| Flight or route | On time | Cancelled | Median delay | Severe | Flights |
|---|---|---|---|---|---|
| B61734 | 74.9% | 1.04% | -6 min | 10.3% | 1,055 |
| JetBlue on SFO → BOS | 76.1% | 1.07% | -7 min | 9.6% | 5,054 |
| All SFO → BOS flights | 77.9% | 1.04% | -7 min | 8.5% | 14,227 |
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026
Why B61734 runs late
Where US DOT attributed the delay minutes on this flight.
airspace and airport capacity, including weather-driven flow control
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
screening or terminal security incidents
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for B61734 on SFO → BOS. Only delays of 15 minutes or more are attributed.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
Does a late aircraft delay this flight?
How often the plane that flies B61734 comes in late, and what that does to the departure.
When the aircraft came in 15 or more minutes late, B61734 pushed back an average of 37 minutes late; when it came in on time or early, an average of 3 minutes late.
Each departure is matched to the flight the same aircraft flew into SFO just before it, using the tail number in the DOT file, 990 of 1,044 departures in all. A departure is left out when that flight is unknown, was cancelled or diverted, or the aircraft had sat for more than 12 hours. A flight the airline cancelled never left and is not in the count, and one flown by a substitute aircraft is matched to the aircraft that flew it, not to the one first planned.
Against the network at the same turn length
| Share of departures | Inbound landed 15+ late | Left 15+ late after a late inbound | Left 15+ late after an on-time inbound |
|---|---|---|---|
| B61734 | 23% | 48% | 13% |
| Network, same turn | 17% | 68% | 9% |
The schedule leaves a normal turn: enough time to clean and board if the aircraft is on time, little to spare if it is not.
The network row is every flight with a scheduled turn of 60 to 89 minutes. How often B61734’s aircraft landed 15 or more minutes late is higher than the network’s and, once the aircraft was late, how often B61734 left 15 or more minutes late is lower than the network’s.
More: Which Flight Numbers Pay for a Late Aircraft lists the flight numbers that pass a late aircraft on.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
From pushback to gate
When it leaves SFO late, does that still matter by the time it reaches BOS?
B61734 pushes back an average of 15.5 minutes late and reaches the gate at BOS an average of 8.5 minutes late. The 7.0 minutes between those two figures are slack the published schedule already carries, which is why a late pushback on this flight does not reliably become a late arrival. It spends 19.0 minutes on the taxiways at SFO, 1.6 minutes shorter than a typical SFO departure in the same hour.
On arrival at BOS, B61734 spends 9.8 min taxiing from touchdown to the gate — ground time a connecting passenger sits through before they can even leave the aircraft, on top of however late the flight itself ran. That is about what any arrival at BOS spends on the ground before reaching the gate.
Departure delay is averaged over every pushback and arrival delay over every completed arrival, so the two counts differ by the flights that never reached BOS. Taxi-out is gate to wheels up and sits inside the scheduled block rather than on top of it; the comparison is 20,911 departures from SFO scheduled in the clock hour B61734 most often leaves in. Taxi-in is landing to gate, compared against every arrival FlyerIntel has on file at BOS (440,886 flights), not just B61734’s own. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026
The hour it leaves SFO
Part of any flight’s record belongs to the clock rather than to the flight. B61734 has one departure time, so this is what that time is worth.
On-time arrival rate. 20,911 departures from SFO are scheduled in the 12 PM–1 PM hour over the period, against 435,779 across the whole day.
B61734 is scheduled out of SFO at 12:20 PM, in the 12 PM–1 PM bank. Departures from SFO in that hour arrive on time 72.8% of the time against 78.7% across the airport’s whole day — the slot alone is worth 6.0 points worse before anything about this particular flight is considered.
The two airport figures cover every departure from SFO to every destination, so they describe the slot rather than this journey — the like-for-like comparison against the route is above. Hours are scheduled local, and a number whose schedule moved between banks inside the period has no single hour and is not described here at all. Why the hour matters.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Hours below 120 departures are not scored.
By day of week
Does B61734 run worse on particular days?
Tuesday is historically the most reliable day and Monday the least, a gap of 17.3 percentage points.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Days with fewer than 120 operations are not scored.
When it goes wrong
The average describes a usual day. This is the day that ruins a connection.
60 min late
against a median of 6 min early
B61734 has an average that understates its risk: a typical arrival is 6 min early, but the worst tenth are 66 minutes worse than that. If the trip has something unmissable at the end of it, the median is the wrong number to plan against.
Percentiles over 1,055 operations; cancelled and diverted flights are counted separately.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
Other flights on this route
Same airports, same journey, different odds of arriving on time.
| Flight | Airline | On time | Median arrival | Operations |
|---|---|---|---|---|
| DL400 | Delta Air Lines | 90.4% | 13 min early | 784 |
| B6434 | JetBlue | 86.2% | 11 min early | 988 |
| AS356 | Alaska Airlines | 85.1% | 9 min early | 712 |
| UA2647 | United Airlines | 83.0% | 9 min early | 835 |
| UA1665 | United Airlines | 81.8% | 8 min early | 1,045 |
| B6734 | JetBlue | 76.9% | 6 min early | 810 |
| B61734 this flight | JetBlue | 74.9% | 6 min early | 1,055 |
| DL977 | Delta Air Lines | 71.6% | 4 min early | 829 |
Every departure listed carries at least 600 operations, so the comparison is between figures that mean something. B61734 is placed in the same ordering rather than left out of it; the rows around it are the most punctual departures on the route, not all of them, so this is a comparison and not a rank. Schedules change; confirm the departure still operates before booking around this.
Data and methodology
Calculated by FlyerIntel from 1,055 records of B61734 operating SFO → BOS, published by the US DOT Bureau of Transportation Statistics. A flight counts as delayed when it arrives 15 or more minutes after schedule. Cancelled and diverted flights are excluded from the on-time rate and reported separately. Flight numbers are resolved as carrier plus number plus route, because the same number serves different routes over time.
Full methodology · Data sources · Report a problem
Related research: Most and Least Reliable Flight Numbers · The Delay You Inherit · Making Up Time in the Air
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