If you’re a frequent flyer, you’ve definitely spotted those black or red triangle stickers above some of the windows on your plane, two on each side to be specific. I’ve never had any idea why they are there, but Travel + Leisure has the answer I’ve been searching for.
According to the magazine, the triangles line up with the edge of the aircraft wing. They act as a sign to pilots and flight attendants, informing them where to look should they need to inspect the wings for any problems.
If flight crew need to check the wings, these triangles let them know the best vantage points for the slats and flaps outside. The markings are especially helpful in wintery conditions to make sure the wings are properly de-iced (an inspection required before takeoff, although this is generally done by crew on the ground).
Of course, the wings are also the center of gravity, so head towards the triangles should you get nauseous!
T&L also points out that the triangle seats provide the best view over the wings for your pictures and videos.