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OSN to FSI: distance & flight time
Osan (Osan Air Base) → Fort Sill (Henry Post Army Air Field (Fort Sill))
6,685 mi
10,759 km · 5,809 nm
13h 34m
estimated nonstop flight time
-15h
time difference · heading northeast
See live OSN→FSI fares Phone-only fares on this route — call free
Flight time details
6,685 miles nonstop takes roughly 13h 34m gate to gate, flying northeast. Add 45–90 minutes per connection if there's no nonstop service. Remember to factor the 15-hour time set-back when reading arrival times on your ticket.
The two airports
- OSN — Osan Air Base · Osan, South Korea
- FSI — Henry Post Army Air Field (Fort Sill) · Fort Sill, United States
Distances are great-circle ("as the crow flies") — the same basis airlines use for frequent-flyer miles.
Alternate airports can cut this fare
Flying from or into a nearby airport is the #1 trick our agents use to beat online prices. Call and we'll compare every combination on one call.
Near OSN
- ICN · Incheon International Airport41 mi away
- SWU · Suwon Airport10 mi away
- SSN · Seoul Air Base (K-16)25 mi away
- GMP · Gimpo International Airport35 mi away
Near FSI
- LAW · Lawton Fort Sill Regional Airport6 mi away
- DUC · Halliburton Field28 mi away
- HBR · Hobart Regional Airport44 mi away
- SPS · Sheppard Air Force Base-Wichita Falls Municipal Airport46 mi away
Frequently asked questions
How far is OSN from FSI?
The flight distance from Osan (OSN) to Fort Sill (FSI) is 6,685 miles (10,759 km, 5,809 nautical miles), measured along the great-circle route airlines actually fly.
How long is the flight from OSN to FSI?
A nonstop flight takes about 13h 34m gate to gate. Actual time varies with winds, routing and season — eastbound transatlantic flights, for example, are usually faster than the return.
Are there nonstop flights from OSN to FSI?
Nonstop service on OSN–FSI depends on the season and the day of week. Run the fare search on this page with the nonstop filter applied to see current direct options; when there is no nonstop, a single connection through a carrier hub adds roughly 2–4 hours to the 13h 34m nonstop estimate.
What is the time difference between Osan and Fort Sill?
Fort Sill is 15 hours behind Osan.
What is the cheapest way to fly from OSN to FSI?
Compare live fares online, then call CheapoTrav — our agents have unpublished consolidator fares on OSN–FSI that never appear on search engines, with no booking fees.
Why are some OSN to FSI fares phone-only?
Consolidator contracts let us sell certain OSN–FSI tickets below the price airlines permit us to publish online, so those fares can only be quoted over the phone. Call the travel desk and an agent will check phone-only inventory for your dates.