With the development of science and technology, why don't the plane use electric doors and the flight attendants have to shut it down manually?

How can a small electric door defeat an R&D engineer who can send a plane to the sky? In fact, this seemingly simple manual switch action contains many safety design principles. With the improvement of people's living standards, the modes of transportation have become diversified. In the past, only local tyrants could fly, but now it has become popular. More and more people are willing to take the plane as the choice of long-distance travel and experience the feeling of flying. In addition to the scenery overlooking the ground, there is also a beautiful scenery on the plane, that is, our flight attendants. At present, when major airlines recruit flight attendants, the selection criteria are very high. In addition to being tall and sweet, they also have good academic qualifications and emotional intelligence.

For example, the stewardess of Air China is dignified and elegant, while the stewardess of China Eastern Airlines is elegant and intellectual, revealing infinite beauty. We won't discuss which stewardess is beautiful here. I believe that many old drivers who often fly will have their own opinions. Along the way, flight attendants not only provide thoughtful service for passengers, but also shoulder the heavy responsibility of passenger safety.

Today, let's talk about the safety of airplanes. Many friends should notice that when the plane takes off and lands, the doors are opened and closed by the stewardess. Such an advanced civil airliner needs the cabin door to be manually opened and closed by the flight attendants. Is it because it cannot be mechanically controlled? Of course not. How can a small electric door defeat an R&D engineer who can send a plane into the sky? In fact, this seemingly simple manual switch action contains many safety design principles.

As we all know, any mechanical device, no matter how perfectly designed, may lead to mechanical failure. For the machine on the production line, if there is a mechanical failure, it is a big deal to stop and replace it with a new one. However, for a giant flying in the sky, what if there is a mechanical failure in the aircraft door? Hit it with a hammer? Precious rescue time was wasted. Therefore, it is necessary to ensure that the door can be opened in dangerous situations, so there is no machine smarter than human beings. Therefore, the door must be designed as a manual switch, which is opened by the flight attendant when escaping. In addition to manual control to keep the plane safe, there is also a design to protect passengers' safety, which is "redundant design". To put it bluntly, one device is enough, I have to use three devices! What's the good of this? One piece of equipment is broken, but there are two spare ones. This is especially important for vehicles like airplanes that can't tolerate any carelessness. There are also redundant devices that must be designed as odd numbers and must work independently of each other. Therefore, when there is a "difference" between devices, the minority is subordinate to the majority to ensure the safety of passengers to the greatest extent.