Next time you’re in an airplane, scan the walls. You might spot four black or red triangle stickers above the windows, two on each side of the plane. They mean a lot to flight attendants.
If you go up to the seats with the triangles and look out the window, you’ll notice the stickers line up with the edge of the airplane wing—one for the front, and one for the back.
When flight attendants or pilots need to look at the wings, the triangle stickers act like a sign telling them exactly where to look. If they’re checking the moving parts of a wing (the flats and slats) for problems like ice, they won’t have to crawl over ten passengers before finding the best view, according to Travel + Leisure.
Queasy passengers might find their own use for the wings, too. The wings are the center of gravity on most planes, and the aircraft moves up and down from the wings like an axis. Sort of like sitting in the middle of a seesaw, you’ll get the least movement and smoothest ride by sitting over the wings, according to pilot “Captain” Joe.
The seats below the triangles can also sometimes be referred to as “William Shatner’s seat.” The phrase is taken from an episode of The Twilight Zone where Shatner sees a goblin out on the wing of his airplane.
There’s also one other hidden perk of these black triangles. If you’re flying an airline that allows you to choose your own seat, look for one of the triangles in the cabin. Anybody who loves taking out-the-window shots or videos for Instagram will get the best view over the wings from these seats.