AI4174Air IndiaIn the air, 17 min late
Left SFO at 11:12, 17 min after its 10:55 slot.
Track AI4174 →
live
Direct flights from San Francisco (SFO) to Kolkata (CCU): 7 nonstop departures observed each week across 1 airline. 71% of the last 7 operated flights arrived within 15 minutes of schedule. The median arrival is 10 minutes late. No cancellations were recorded across the 7 tracked flights. The nonstop covers 12,578 km, an estimated 16 hours 38 minutes in the air. Measured by Pro Flight Search from live flight boards at San Francisco and Kolkata. Updated 12 October 2026 at 20:30 UTC.
Today, SFO → CCU
Mon 12 Oct · local times- 10:55 AI4174Air India Left 11:12 +17 ·
Checked SFO board 13:30 · CCU board 22:18
SFO
San Francisco
busy · +17
CCU
Kolkata
smooth · +0
12,578 km · ~16h 38m est.
Runs mixed · 1 airline · 7x weekly · nonstop
71% on time
of the last 7 operated SFO → CCU flights arrived within 15 minutes
Median arrival delay is +10 min. 0 of 7 tracked legs cancelled in the sample. Will a delayed flight be cancelled? →
Median arrival+10 minacross the last 7 operated legs
Flight time~16h 38mestimated from route distance
Weekly departures7x1 direct airline on the leg
The week
scheduled departures · origin local time06121824
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Air India
Each mark is a scheduled departure at its origin-local time, observed operating in the last 7 days. Today is highlighted.
Who flies it
observed on the boards · 7 daysAir IndiaAI71% on time
Flights AI4174 10:55 daily
History
operated legs · board outcomesActual board outcomes rather than schedules, paired departure and arrival per flight and day.
Full board history, day by day →
Airports right now
live boardsnext sweep in 120s
How the San Francisco to Kolkata route actually runs
Pro Flight Search records official board updates for nonstop SFO to CCU flights through the day: schedules, estimates, gate pushes and actual departures. The verdict above comes from operated flights, so it reflects what this route does rather than what the timetable promises.
Planning around a delay? Live airport delays · Weather delay risk map · Will a delayed flight be cancelled? · Do planes make up time in the air? · How we measure
Cite this data
Journalists, bloggers, and researchers may cite this page with attribution and a link to Pro Flight Search.
Suggested citation
Pro Flight Search — San Francisco (SFO) to Kolkata (CCU) route reliability, measured from operated flights on official airport boards.
Canonical URL
How we measure this →
https://proflightsearch.com/search-flights/SFO-CCU
SFO to CCU questions
Is SFO–CCU running on time right now?
Smooth skies ahead. The departure side at SFO is the weaker end, route health score 89/100. The airports section above carries the live status and delay window at both ends.
How long is the flight from SFO to CCU?
Great-circle distance is 12,578 km. With typical jet cruise speed plus taxi, climb and descent, expect roughly 918–1108 min gate-to-gate on this route.
How often does SFO–CCU fly?
Air India runs the route with about 7 flights a week (daily). Since one carrier owns the route, a single disruption tends to ripple through the day.
What does the route health score measure?
A blend of departure-side delay at SFO and arrival-side delay at CCU, computed from rolling delay windows (refreshed every 40 minutes) with a daily-rollup fallback. Current MVFR, IFR, or LIFR endpoint weather caps the score when flight rules can limit throughput. Higher is healthier: 100 means operations are clean at both ends.
.