Airplane windows have 3 pieces of glass: the outer one keeps the pressure at bay, the inner one deals with damage from inside, and the middle one, in which the hole is made, regulates the airflow. The aperture helps balance the pressure difference and prevents moisture from condensing between the glass panels.
When boarding the plane, we always hear a noise even though the engines aren’t working yet. It is caused by an APU that provides power for the systems while the engines are out. It also starts the engines. Such a power unit is also helpful in poorly equipped terminals where proper maintenance is unavailable.
Air Marshals fly incognito and can quiet down a troublemaker or even disarm a terrorist. The USA, France, Canada, and other countries have their own Air Marshal Services, and there’s even a movie about their work.
Some airplanes have small hidden rooms for the cabin crew where they can relax during lengthy flights. These CRCs aren’t especially comfortable: you can only crawl in there, but you can lie down for a while and rest.
These handles are made first and foremost for the flight attendants to hold in case of panic onboard so they aren’t pushed off the plane by passengers rushing to the exits.
Have you ever wondered where the air we breathe onboard comes from? It’s actually being bled from a compressor stage of each engine turbine. This is perhaps what served to fuel a superstition that airplane air is dirty. However, no need to worry: the air is filtered and cooled first, and the filters, in fact, retain up to 95% of bacteria.
This device appeared on aircraft after an unsolved crime perpetrated by some Dan Cooper: he hijacked a passenger airplane, received a ransom, and escaped with a parachute. Since then, all Boeing and Airbus planes have been equipped with a Cooper vane: a device that doesn’t let the doors open mid-flight.
You probably noticed those small black triangles onboard some airplanes. As an Airbus A320 captain says, they mark the places where the wings can be best seen from. A visual examination may be required if pilots have doubts regarding the positions of the flaps and indicators are out of order. Fortunately, this is a rare case.