Thanks for all and that link, but yeah I was assuming 18==19 already and meant to understand runway numbers, maybe should have left out that detail.

Actual question still sticks: Takeoff on 18 southwards basically makes you follow the river immediately. Where did this guy encounter his left/right decision, to get back towards white house? he must have made almost a uturn then?

And even assuming the article is a bit inaccurate and he took of northwards (thanks for pointing out the patterns pilots have to fly if doing that @ others): I still cannot imagine how that plane flew and where it matches the description of: "When I reached 1500 feet I looked down. I was crossing the river. It went right and left."

???

I always find it funny how shortly after CGPGrey posts about a thing (or John Oliver does a segment on LWT), a large number of commenters will speak on it as experts at the next available opportunity. It's obvious how many of us watch the same channels.