I started in the late seventies. I had a CO who would join up at the range, as 3, with a stogie going full bore. In the eighties, it wasn’t unusual for 2 out of 3 pilots in a Boeing to be smoking. Do three hours in a Citation with a smoker!

On the 727, the outflow valves where located at the rear near the airstairs. If th3 plane has pressurization problems, maintenance would come out with a weed sprayer filled with Gunk cleaner, free up the valves from the tar and nicotine.

GF