The question of how to make LEGO airplanes fly came up in our house at regular intervals ever since my kids started making them. “There got to be a way to make it move through the air without me holding it,” kept insisting my oldest son. There might be quite a few ways to do just that described on the internet, but I like my kids to invent things and come up with their own ideas. That’s why it took my son about a year to come up with this brilliant (in my opinion) way to make LEGO airplane soar through the air to everyone’s delight. And to keep doing it over and over again!
In the past year we tried a couple of different ideas to keep a LEGO airplane in the air. None entirely successful. This year was the first time my 8-year old suddenly exclaimed, “Hey, let’s try a zipline from the top floor into the backyard!” I went in search of a string, while my son designed a LEGO airplane with an avid support of his 5-year old sister. On her insistence most of the pieces used were from her LEGO friends collection.
I dutifully climbed to the top floor of our house and tied the kite string to the rail of our balcony. My husband tied the other end of the string in the back yard. I hung the LEGO airplane’s own string around the kite string and after kids counted to three I LET IT GO! It took airplane all of few seconds to slide down our zip line and come to a stop. We were a bit disappointed.
That’s when my husband came up with the idea to attach an additional long string to the airplane, so that it could be pulled up to the deck and be dropped down again. That was perfect! Really, really perfect! My son could sit on the deck and drop-and-pull his LEGO plane all day long (and that’s exactly what he did).
You don’t need a multi-level house to enjoy this activity. You can tie a string between a tree and a playground structure. A child can sit on a tree (as long as you feel safe with him/her doing that) and drop airplane and pull it back up. You can also find some multilevel furniture that can be used for this purpose right in your home.
On subsequent tries we added a paperclip. Not only it made for a smoother flying, but also you can not really see it and it looks as if airplane really flies.
What you need
LEGO airplane of your own design or use our design for inspiration
Kite string or similar smooth string (for the zip line + for the pull-back line)
A short piece of string, ribbon or yarn (to go around the airplane and hold the paper clip)
Optional: Kitchen Twine or similarly rough string (for comparison and experimentation purposes)
How to make a LEGO airplane FLY
To start this project you need to make a LEGO airplane. You probably can come up with your own ways to make an airplane, but I share ours for inspiration.
Now you need to attach a bit of string around the airplane. Just lift the front of the airplane, put the string down and put the pieces back down.
Now pull the paper clip through this string.
The zip line is a kite string we attached to the second floor balcony and dropped down into the backyard, so the other end could be tied down there. Put the paperclip on the zip line.
If you let your airplane go right now, there is no way to bring it back up! So one more step.
Tie a long string to the paper clip on one end and tie the second end around the deck rail (or put you feet on it, so it doesn’t escape from you and you don’t have to tie it)
On the pic above: zipline is on the right, and the left string is what we used to pull the plane back up. The left string is a kitchen twine. (It was a disappointing choice since it kept tangling up all around itself. If you are doing it for fun and not for experimental sake, use kite string for both lines).
So, now that you are all set up and know what to do, all you have to do is sit and drop your LEGO airplane, watch it slide down, then pull it back up.
My 8-year old son can sit on the deck and do this project for hours on end. I asked him what was so exciting about it. He said that it was that one split second when he let the airplane go from his hands. Every time he did it he expected it to crash and all the little LEGO pieces fly in all directions. But the zipline carried it down safely… almost every time.
If your kids are anything like my kids, then occasional crash landing was inevitable and even encouraged.
The LEGO airplane Science
Talk about how gravity helps airplane get down.
Balance an airplane on one finger. Depending on the design of your airplane, the center of the structure might not be the best place to balance it. It’s because the geometrical center is not the same as the center of gravity. All the forces of gravity act on individual atoms that make up your airplane. The concentration happens in the center of gravity.
What force do you use to get the airplane back up? Pulling against gravity.
You may or may not want to link this to the discussion of an amazing device called pulley. My son is now at work inventing just the right pulley for getting the airplane back up with less effort.
In mood for some experimentation? Mark how long it takes the airplane to get down on a kite string and how long it takes to get back up. Change the string from kite to kitchen twine. Note the time. Notice the difference? It takes airplane five times as long (or “forever” in the kids world) to get down and it’s challenging to pull it back up!
But wait, there is more
Looking for more aviation projects? Why not make an airplane! We made ours from a plastic bottle, papier-mache glue and lots of newspaper! It lasts for years! Get the instructions HERE or PIN for later.
If you like to read about flight and airplanes, we put together a large collection of books. We divided them into four categories: Top Ten Favorites, For the Little ones (0-3), As They Grow (4-8) and For Very Serious Explorers (8 and up). You can find the list of books with suggested aviation activities HERE.
Here are some more activities to celebrate Aviation day from around the web.
The very best airplane Unit from The Natural Homeschool
Aviation Learning pack for Preschool from Year Round Homeschooling
Learning about Flying with Paper Airplanes from Tree Valley Academy
Fly with Me Science Kit from Groovy Lab in a Box