There’s a reason noise-canceling headphones exist, air travel is loud. From the second you walk through the planes door and are greeted by buzzes and hums, to mid-flight’s roars, and landing’s crackles, departure to arrival is a grab-bag of strange sounds, which is nerve-racking. But what are you hearing exactly and why? And is it safe?
Boeing mechanical engineers Marc Levy and Mike Leary broke down the noises we hear when we fly, and explained why they’re not symptoms of break downs and we have nothing to worry about. In fact, most of the sounds that scare us signify healthy functionality. phew.
For example, that whining or barking that sounds like there’s a dog beneath the cabin is just the power transfer unit checking that hydraulic pressure is balanced when the pilot push-backs and taxis with only 1 engine. The unnerving snaps and cracks you hear on takeoff and landing isn’t the plane falling apart, it’s just the natural movement of the plane’s pieces. See, we imagine everything is bolted down, but that’s not the case. Due to the shifting pressures within the plane, everything on the aircraft is designed to adapt to the plane’s natural expansions and decompressions by being attached by tie rods. So things like the bins, walls, kitchen compartments, etc, aren’t solid fixtures, conversely they’re granted room to change with fluidity and ease. Which causes the bumping and banging.
As Levy explains, ‘This means that when you give the airplane a little jolt or bump or the fuselage expands that last little bit, all of the stuff on the inside is going to adjust and sometimes bump into things. So when an airplane touches down for a landing and does a little hop, don’t be surprised when you hear a reasonable amount of creaking, cracking and thumping sounds – it’s just everything moving around like it is supposed to.’
Read the entire article of Marc Levy and Mike Leary’s summation of what everything we hear during air travel means via Quora here, and turn up those headphones.