Intruder, they actualy depart Renton to a variety of airports. The greatest number go to Moses Lake (KMWH); others to Paine Field (KPAE). They occasionally go they occasionally go to Boeing Field (KBFI) or other airports.
kkoran:
I seldom see 737s in PAE. I see LOTS of them at BFI.
While they may fly east and possibly do touch & goes at MWH, they normally land at BFI, where the customer delivery center is. While things may have changed since I left Boeing in 1998, their goal then was that the initial flight would be the ONLY Boeing flight (i.e., no squawks), and the 2nd flight would be the delivery flight.