# The South Flow SeaTac Arrival Corridor


From Gas Works Park, you can watch jets descend to SeaTac in a steady stream,
one every minute or two. I’ve lived in various neighborhoods in Seattle, all
under this corridor -- SLU, Eastlake, Fremont. I didn’t think much of this fact
until fairly recently, when I started taking flight lessons and becoming
generally more actively interested in aviation.

![The South Flow SeaTac Arrival Corridor; Red indicates arrivals](https://benjamincongdon.me/blog/2025/12/20/The-South-Flow-SeaTac-Arrival-Corridor/south_flow_tracks.jpg)

As I write this, I have [FlightRadar24](https://www.flightradar24.com/) popped
open and can see a dozen or so jets in or entering this funnel. Planes enter the
approach north of Seattle around Lynnwood or Shoreline, hug I-5 south, passing
Green Lake and Lake Union, eventually descending through South Seattle into
their SeaTac landing. There’s something comfortingly mechanical about this
rhythm.

![FlightRadar24 snapshot of the arrival corridor](https://benjamincongdon.me/blog/2025/12/20/The-South-Flow-SeaTac-Arrival-Corridor/flightradar24.png)

Of course, depending on the wind, SeaTac can also flip to a “north flow” pattern
where the funnel over Green Lake becomes the departure direction instead of the
arrival, but the south flow is used about two-thirds of the time.

It’s also notable how entirely non-dramatic this routine is. Even in the foggy
soup of Seattle clouds, the rain, negligible visibility, SeaTac continues to
operate. I’m still quite early in my private pilot training and haven’t touched
instrument flying yet, but I have a fledgling appreciation for what makes this
possible: procedures, precision instruments, and skilled piloting. The fact that
you can fly through the clouds and only see the runway a few hundred feet before
landing (safely, of course) is an impressive feat of engineering and aviating.

I’ve now been thinking of this arrival corridor as one of my favorite landmarks
of Seattle. It’s “invisible” and it’s undoubtedly less of a recognizable
landmark than either of the floating bridges, the canal bridges, or any of
Seattle’s other notable infrastructure landmarks. But nonetheless, I think about
it nearly every day -- whether it be on a run, driving to work, or just in
hearing the quiet hum of a plane flying overhead.