If you have observed the engine of the aircraft before boarding, you will find that the engine rotor of almost all large passenger aircraft will be painted with a spiral pattern at the front. In fact, this spiral pattern is not just decorative, but it is for safety reasons. Set.
In fact, we should all know that its suction is very strong after the start of the launch. During the flight, the birds are easily sucked into the engine nearby, causing a safety accident. However, the birds have the instinct to avoid rotating objects, so the birds see the spiral in the distance. The engine rotation of the pattern is generally active away from the aircraft.
In addition, before taking off on the plane, the ground staff can also use this spiral pattern at a distance to determine whether the aircraft engine is started, thus avoiding danger.