If you've ever flown on an airplane, you must have heard a number of strange sounds such as a sudden pop or hiss during takeoff, flight, or landing.
There are countless sensations and noises involved in the operation of an aircraft before, during, and after a flight. Modern airplanes are highly complex machines with an array of moving parts that make noise and have attendant sensations.
These noises may startle you, but in most cases you don't need to worry, as they are normal and come from certain missions in the plane.
What do strange sounds in the plane mean?
Banging while boarding the plane
It is common to hear a noise coming from below when boarding an airplane or waiting in your seat at the gate before take off. The sound is likely to be caused by cargo operations or luggage being loaded under the passenger compartment.
The sound of air when boarding a plane
Before take off, one of the first sounds you hear is a blowing or whistling of air coming from inside.
This sound occurs when the aircraft's ventilation system moves from an outdoor system to an indoor one. Some interior lights may also flash when this happens.
Two hits and a high-frequency buzzing just after take-off
When the plane lifts off the ground, the pilot retracts the wheels in the fuselage and closes the flaps behind them, one by one, which makes a two-stroke sound.
This disturbing noise comes from the retraction of the wing flaps that were needed to get the plane off the ground. Both procedures are part of the process of "cleaning the plane" to make it smooth to fly.
“Doors to arrival” and “cross check”
When the aircraft doors are closed, the escape slide is automatically enabled for safety reasons. This is why you will hear “Doors to arrival” as you approach the gate to remind the flight attendants to remove the chip.
The sound of “cross check” is instructing the crew to check the sliding gate again.
You may hear this sound from a flight attendant at any point in the flight. This call is a request for a crew conference call that calls each flight attendant to report that they have completed all of their designated safety checks.
A rumble during landing
As the plane begins to descend, the engine noise will decrease because it is no longer accelerating. In order to slow the aircraft down so it can land safely, long panels on the wing that lift up to increase drag and are known as "flight spoiler panels" will be activated. When you activate these panels, you'll hear cabin rumbles and feel vibrations.
Revving engines during touchdown
Once the plane has touched down on land, it sounds like the engines are revving for takeoff. This is just the captain reversing the engine thrusts to help slow down the aircraft. When this happens, you’ll hear the loud noise of the engines and feel pushed forward in your seat because of rapid deceleration. Want more travel info? Here’s what airplane mode on your phone actually does.