7:17 PM: For those wondering about the low thump-thump-thump of a military helicopter over West Seattle – unlike some recent helicopter passes, this one is on tracker, and it’s a U.S. Army Chinook helicopter from JBLM in Pierce County. We don’t know its exact mission but looking into previous similar passes, they do often head up this way on training flights.

7:21 PM: After flying north and then east along West Seattle’s shore to Duwamish Head, the Chinook headed north and is currently flying along Magnolia, Ballard, and beyond.

7:24 PM: And now retracing its path southward – so you might hear it again.

7:35 PM: Appears to be headed home, already off the west shore of Vashon Island.