Drilled holes in the lower part of aircraft windows
Something I've always wondered and never yet worked out.
Normally I sit on an aisle seat so tend to forget about it but today I managed a window seat so, be an nosey thing that I am, decided to watch the world pass by. I then noticed the small "holes" (ok, they are only shallow) drilled into the bottom of each window. I remembered that this is the best place for answers to state what their purpose is.
Many thanks