The above plane just flew over my house, at about 3,000 feet (1,800 above ground level). Quite noisy.
It's a Boeing 737-MAX 8 test plane called the "Spirit of Renton", the first 737-MAX ever built. It first flew in January this year.
It has an interesting trailing
Given that it's a test plane, it's likely to be flying around in random circuits, maybe leaving contrails. So look out for it in the "chemtrail" pages.