Hanuman and Nala are hanging out together and having a chat.
Hanuman: Nala, last night I dreamt about a strange kind of flying machine.
Nala: Interesting! Tell me more…
Hanuman: It had some rotating blades, moved upward but not like a rocket.
Nala: Ah… I got it! Come with me…
Nala takes Hanuman to a maple plant and points to its seed.
Nala: Did the flying machine look like this?
Hanuman: Yes, but upside down. I might have seen these seeds earlier. May be that’s why I had this dream. But how can any machine fly like the one in my dream?
Nala: It can! It is called the aerial screw or helicopter mechanism.
Hanuman: What is that?
Nala: To know about this, we need to look into future. My dad Vishvakarma’s book can help us. It can take us to a technology any time in the future or past and help us access the fourth dimension time.
Hanuman: What is that?
Nala: I’ll explain that later. Now, come on, let’s travel to 1480; a time when Leonardo da Vinci, the famous polymath lived.
Hanuman: What does polymath mean?
Nala: It means the person knows a lot about many subjects and can combine the knowledge.
Hanuman: Oh!
Nala: da Vinci was an artist, architect, engineer and mathematician. He made drawings of various flying machines, one of which is famously called the aerial screw. See this…
Hanuman: Oh! This actually looks like an inverted screw but made of cloth!
Nala: When you use a screw on wood or a wall, the metal pierces throw the solid object and holds tights. But, to fly, the object needs to be light and hold on to the air. That is why lightweight materials are used.
Nala then turns to 1939 in the book and points to the world’s first commercial helicopter.
Hanuman (jumping with excitement): This is the flying machine I saw in my dream!
Illustration: Sahil Upalekar
Nala: So what you saw was the first vertical flying aerodyne machine, made by Igor Sikorsky, the father of modern commercial helicopters.
Hanuman: But it looks different from da Vinci’s model?
Nala: da Vinci’s model is conceptually correct but, in reality, it is heavy. A fan’s blades titled at an angle of 5-10 degrees will do same job as that of a screw.
Hanuman: Oh!
Nala: Do you want to make one and see for yourself?
Hanuman: Of course! Using maple seeds?
Nala: Ha ha! No! Using paper.
(See the Paper Helicopter instructions)
Hanuman: Before we start, tell me, why are maple seeds in this shape?
Nala: These are called maple helicopter seeds or winged seeds because the seeds are attached to the wings (leaves). When the wind blows, the seeds fly far away from the tree so that they can spread out and grow in newer areas.
After making the paper helicopter, Hanuman wonders what to do with it…
Nala: Throw it up.
When Hanuman does that, it spins like a helicopter and falls down.
Hanuman: Wow! It works like an aerial screw!
Nala: You know what, in the future, almost every house will have this aerial screw inside their house.
Hanuman: A helicopter in every room?
Nala points to another page in the book.
Nala: It’s called the ceiling fan. It’s an aerial screw attached to the ceiling. So, instead of flying away, it pushes the air down.
Hanuman: The concept is the same but the application is different.
Nala: So, now let me explain about the fourth dimension…
Hanuman: No, not now! I want to play with my helicopter.
Hanuman plays with his toy without realising that this idea would help him save a life sometime in the future.
The author is the founder and CEO of Vaayusastra Aerospace, an IIT-Madras incubated ed-tech startup that offers Air Science workshops for children between five and 14 years.
