Hooks on the wings
In most planes, to use an emergency exit slide, passengers have to step onto a smooth and slippery wing. To make this easier, a special hook was designed: a safety rope is led through it, with one end attached to the door and the other hooked to the wing at the base of the slide. Holding on to the rope, passengers can safely evacuate.
An ax in the cockpit
According to many countries’ laws (such as the USA), an ax is a piece of emergency equipment and must be stored in the cockpit. An ax can help contain a fire, open a stuck door, or even hack a new one — there are markings on the fuselage that show the best place to make an emergency exit.
A hole in the windows
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.
An auxiliary power unit
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 Marshal Service
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.
Crew rest compartments
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.
Handles by the emergency doors
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.
Air conditioning system
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.
A Cooper vane
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.
The black triangle
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.