The run up to the end of the year can be handy if you want to see jets on test flights because Boeing is looking to get as many sales completed as possible before the end of the financial year. While it wasn’t built at Everett, a Vietnam Airlines 787-10 was there for rework/modification and then delivery. I love Vietnam Airlines because they have an interesting livery in a time of white planes with limited color.
I was able to catch it taking off one Saturday morning. The light was great as it rotated and climbed away. Later in the afternoon, Nancy and I had been out to see the salmon run and she was fine with a small diversion to Paine Field to catch the return. The light had faded a little compared to the lovely morning conditions, but it was good to catch the returning jet. I think it was delivered not long after this.