Spiral image on airplane engine? Do people draw for fun?

Jet engines are always the most overwhelming and often we look before boarding a plane.

The thing is, have you ever noticed a spiral sign at the tip of the propeller shaft and have you ever wondered why people paint this spiral? Is it just for fun?

This is really a mandatory sign and its function is to ensure safety for ground personnel as well as the aircraft itself!

Safety signs for ground personnel

Its first purpose is to help ground personnel know if the engine is working.

The spiral shape is a common sign that is painted on the propeller shaft of the jet engine. For aircraft using turboprop engines or helicopters, there are streaks of color at the end of the wings. Whatever it is, the first purpose is to help ground personnel know whether the engine is operating (whether the rotor is rotating) and which direction to turn. In addition, the helix sign also helps them to know the fast or slow rotation engine - a very important factor to prevent the risk of being sucked into the engine.

The engine wrench helps them realize whether the area around the engine is safe or not.

The ground crew at the airport is very much and they perform many different functions around the plane, especially when the plane landed and started rolling into the stop position. There will be ground workers who handle luggage, refuel, check the technology, . In an airport environment which is very noisy, ground workers often wear noise-canceling headphones or helmets, Even if you don't wear it, it's hard to tell which engine is running in dozens of aircraft with roaring engines. So the engine wrench helps them realize whether the area around the engine is safe or not.

On jet engines, you can only see the spiral when facing the plane.

In a post on KLM's blog - Dutch royal airline author Renee Penris said: "There is always a dangerous area around every engine. Such as the engine of the Boeing 787 Dreamliner when The resting distance is 4.57m from the tip of the propeller center, everything is too close to the engine even though it is resting, the slow rotating propeller can still be sucked in. "

He added: "The spiral appeared 50 years ago - 60 years ago. On old aircraft with large propellers in front of the engine, they could turn around when the wind was strong. One. The number of motor types must be rotated before the fuel is loaded to start up, so the winding is very important to identify the engine's operation .

This spiral does not play the role of bird chasing as people think.

Ground personnel or maintenance engineers can easily see the direction of rotation of the propeller, in the right direction, thereby informing the crew or the pilot so that they can proceed to the next procedure ( Do you remember the plane when you used to have someone to start the propeller manually?). Of course, such procedures no longer apply to new engine types because everything is replaced by an auto-start system. On jet engines, you can only see the spiral when facing the plane, and with propulsion aircraft, they have signs on the propeller so that when spinning at high speed, these marks forming a seamless circle in the air helps you know it's very dangerous, avoiding "falling head".

Above is the video recording of the crash of JD Bridges - a carrier USS Theodore Roosevelt who was sucked into the jet engine of the A6 Intruder that was about to take off in February 1991. Luckily As Bridges was only wounded and saved his life as a helmet, the hat jammed the engine causing it to slow down and other staff immediately informed the pilot to turn off the engine.

Chasing birds?

Since the 80s of the last century, airline companies began investing in research on the engine windings when it showed effective anti-damage resulting in accidents caused by hitting birds. Rolls-Royce explained the importance of the spiral: "When flying, this wrench creates a hallucination flicker when the engine rotates at high speed, making the birds scared and actively away from the engine. ".

However, in a post in Boeing's Aero Magazine, the author is a researcher, the former pilot said that birds are often actively away from aircraft by engine noise and aerodynamics. Therefore, these snails do not play the role of chasing birds as people think. However, there are still many controversies about this issue and whether this sneaking out bird is still "probably", it is best to ask the bird.