8 The oxygen masks in airplanes have enough oxygen to last around 15 minutes, during which the pilot must lower the plane to an altitude that is suitable for normal breathing.

If there is a drop in cabin pressure, oxygen masks on a plane typically drop from the panel above the seats. Then, as instructed before take-off, passengers must wear them covering the nose and mouth and breathe.

The oxygen from this mask lasts around 12 to 15 minutes. Now if that seems short, don’t worry! Experts say that this time is more than enough for a flight crew to get you to a lower altitude where you won’t need the masks to breathe. (1, 2)

9 The door to the airplane toilet can be unlocked from the outside even after it has been locked from the inside.

Yes! Even when you lock a commercial airplane bathroom door from the inside, it can still be opened from the outside if a flight attendant deems it necessary.

It turns out, that under the sign that says “lavatory” on the door, there is a button or catch that lets them unlock the door, allowing it to be opened from the outside. But don’t worry, this button is usually only used in cases of emergency. (1, 2)

10 Cabin crew often have private sleeping quarters on board during long-haul flights.

Long-haul flights often last hours at a stretch and ultra-long-haul flights can even exceed 18 hours. So, to provide crew members with their required breaks, commercial aircraft have a hidden compartment with resting areas. The location and layout of these areas may vary from airline to airline but most crew rest compartments ultimately look like the inside of a futuristic spaceship.

They are also often stocked with essential supplies such as pillows, blankets, and a seatbelt for when there is turbulence. Pilots, on the other hand, tend to have their own separate sleeping compartments. (1, 2, 3)

11 A pushback vehicle is used to bring an aircraft out of its parking position because a plane reversing itself can cause high-speed debris to fly around.

In aviation, “pushback” is a procedure in which a vehicle pushes an aircraft backward to get it out of its parking position. Such vehicles are called a pushback tractor or tug. Does this mean an aircraft is incapable of moving itself backward? Not necessarily. Many aircraft are actually capable of using reverse thrust to do this.

However, the resulting high-speed debris can hurt ground staff or be sucked into the aircraft’s engines. This could also be accompanied by increased noise and damage to airport terminal buildings. So, to be safe, pushback is used as the preferred method to get aircraft out of their parking spots. (source)

12 Winglets on the tips of an aircraft’s wings help reduce the amount of fuel used, saving billions of dollars for airline companies.

Most aircraft today have a “winglet” at the tip of their wing. These winglets help reduce natural vortices that form at the wingtips and thus lessen induced drag on the aircraft. This way, the tiny winglet allows aircraft to use up to 5% less fuel. For a typical Boeing 737 commuter plane, that adds up to 100,000 gallons of fuel a year! Consequently, winglets help save billions of dollars for the airline industry. (1, 2)

13 Airplane windows are always round, and not rectangular, to ensure the safety of the aircraft.

As we know, an airplane has to deal with high air pressure during a flight. With square windows, this would mean that their corners form weak spots on the aircraft’s body along which it could disintegrate. The solution to this then is to use circular windows. Since round shapes distribute pressure more evenly, circular windows provide more stability to the aircraft, making it safer.
(1, 2)

14 Dimming lights inside the cabin during takeoff and landing helps the eyes adjust to darkness quicker. This is crucial during an emergency.

Flight crews usually dim the lights in the cabin during takeoff and landing. But why do they do this? Typically, it takes the eyes about ten minutes to completely adapt to darkness. But in case of emergencies, this would be valuable time lost while passengers and crew members try to get used to dim lighting in situations such as the power going out.

So, by dimming lights in the cabin, it allows the eyes to adapt to the darkness quicker. Also, the emergency path lights and signs are more likely to be visible in dim light than in bright ones, making it easier to get off the plane. (1, 2)