Was flying a 212 some years back. It had the left-side bubble window for longlining, which has a gaping hole in the bottom for clear viz. It was a night flight, middle of winter, planned altitude of 6000' so it was going to be a cool breeze slipping up my left sleeve.
Wanting to block this pesky airflow, I found a slab of thick rubber foam and wedged it into the window from the outside, secured with some gaffer tape. I reckoned that would stop the airflow from coming in.
Loaded the pax and took off, and passing 40 kt, the wedged-in foam went pop and disappeared OUTWARDS, not inwards as expected.
It was a mighty cold trip after that, as I contemplated that b@stard Bernouilli and his laws.
