A field guide to the sounds of an ordinary flight

Almost every noise on a normal flight belongs to a known step, and the sequence rarely varies.

It begins before pushback with a hum and a rush of air as the cabin systems come alive, sometimes accompanied by a rhythmic whirring from below the floor. Then a low whine builds as the engines are started, one after the other, rising in pitch until it settles into a steady note. On the taxi you hear the rumble of wheels over the joints in the concrete, occasional squeals from the brakes, and hydraulic sighs as the aircraft is steered. None of this is unusual, though most of it is inaudible on the ground and startling from a seat.

At takeoff the engine note rises and holds, the rumble accelerates, the nose lifts and the rumble abruptly stops as the wheels leave the surface. Very shortly afterwards there is a heavy mechanical thump and a change in wind noise. That is the landing gear being folded away, and its absence would be a far stranger event than its presence. In the following minutes the engine note steps back at least once, because full power is only needed briefly, and the aircraft settles into a quieter climb. Then comes the whirr of the wing panels retracting into cruise shape.

The cruise is largely uneventful acoustically, which is why the descent surprises people. The engines throttle back to near idle, and the sudden quiet is often misheard as something stopping. Nothing has stopped. Going downhill simply requires less push. Later the wing panels extend again with their unmistakable machinery noise, the gear comes down with another thump and a great increase in wind roar, and after touchdown the engine note surges as thrust is redirected forward to help slow the aircraft. That final loud rush, so often mistaken for alarm, is the sound of stopping.