If you’ve ever snagged a window seat by the wing, you’ve probably spent a good deal of time staring out, trying to sneak a peek of the scenery passing below. After a little bit, though, you might notice something weird on the otherwise flat wing: two yellow hooks about a third of the way to the tip of the wing.
If the bright yellow color wasn’t already a sign that the feature must be important, the placement should, too. Why would any plane design want anything getting in the way of the smooth aerodynamic surface? Well, that hook just might save your life. Here are the other hidden airplane features to scope out on your next flight, too.
When large commercial airplanes have an emergency landing, passengers sitting near the middle leave through emergency exits near the wings. Those wings are high above the ground, so passengers need a safe way to get down. Luckily, safety features make it easy. “Once the door is opened, an escape slide at the rear of the wing will automatically deploy, which you will slide down and distance yourself from the aircraft,” says pilot “Captain” Joe in a video. Find out more things pilots want you to know.
The thing is, getting to that inflatable slide could pose another risk if the wings are slippery. If a passenger slipped and fell, it would be a long drop down to the ground. That’s where the hooks come in.
After the slide automatically inflates and the emergency exits are opened, flight attendants grab two ropes. One is attached between the doorframe and that hook, while the other one leads from the hook to the inflatable slide, says pilot Joe. By holding on to the ropes, passengers can keep their balance and evacuate safely—but the rope couldn’t attach to anything if it weren’t for those yellow hooks. Engineers really do think of everything—you’ll want to know what these common airplane sounds are the next time you fly!