Defining an Engineering Design Problem with Paper Airplanes

Background Information for Teachers

You probably remember making paper airplanes as a kid, and some of your students might be obsessed with making them now. While they might seem like a waste of paper or a distraction in your classroom, paper airplanes are an excellent way to teach your students about the engineering design process. You might think of the engineering design process as primarily about designing, iterating, and testing multiple prototypes of some device or machine. However, before you even start to design, you need to define the problem you are trying to solve, the criteria for success, and the constraints you face when solving the problem. Otherwise, you might design something that "works," but find out that it does not meet some specific goals, is too expensive, requires materials that are not readily available, etc. To avoid wasted effort, it is very important to sort those things out beforehand! If you are unfamiliar with the engineering design process, check out the links in the Additional Background section to learn more.

Think about real planes for a minute. They come in all shapes and sizes (Figure 1), and serve very different purposes. Before they can begin to design these planes, engineers have to define the problem they are trying to solve and the criteria/constraints they have to work with. For example, who is the customer for the plane? What will the plane be used for? How fast does the plane need to go? Why does this problem require a new type of plane? What is the budget and what materials are available to build it? The answers to those questions lead engineers to design very different planes. For example, look at Figure 1 and imagine what the customer for the plane might have wanted in each scenario (a big plane that can carry a lot of passengers and their luggage; a fast, agile plane that can shoot down other planes; and a tiny plane for just a few passengers).

Image Credit: Wikimedia / Public domain Image Credit Image Credit: Wikimedia / Public domain
Figure 1. Three different types of planes. From left to right: a large passenger plane (Boeing 747), a fighter jet (Lockheed Martin F-22 Raptor), and a single-engine passenger plane (Cessna 172).

In this lesson plan, you will be the "customer" who wants to purchase a paper airplane. Your students will form teams of "engineers" that will design and build paper airplanes. Before they start building anything, they need to first define the engineering problem that they will solve. What does the customer want the airplane to do (for example, the plane that can fly the farthest)? What constraints do they have to work with (for example, what materials are available, and how much time do they have)? How will they determine if their plane is "successful" and meets all criteria? While your students will still build and test planes, this lesson will focus primarily on these beginning stages of the engineering design process. See the variations section for ideas about how you can include other steps of the process in more detail.

Additional Background Links

• Engineering Design Process, Science Buddies
• Comparing the Engineering Design Process and the Scientific Method, Science Buddies
• There are many books about making paper airplanes available on Amazon.com and there may be some available in your school's library. Make sure you look for beginner-friendly books with simple designs (some paper airplane books have very complex designs and are intended for more advanced airplane enthusiasts). There are also plenty of videos about how to make paper airplanes on YouTube.

Prep Work (5 minutes)

• Make the "stunt plane" from the paper airplane instructions document and practice throwing it. This plane should be very difficult to throw straight—it will almost always do loops or spirals.
• If necessary, rearrange furniture in your classroom so your students have a straight, open area to throw planes. If you do not have enough room in your classroom, you will have to do this activity in a hallway or bigger room.

Engage (5 minutes)

1. Tell your students that you own an engineering company that makes paper airplanes. Someone has hired you to design and build a paper airplane that can fly as straight as possible. They need a plane that can quickly get from one place to another without crashing. Show them the plane you built (see Prep Work section).
2. Ask your students to watch closely, and throw the plane.

   What happened? Did anything go wrong?

   The plane was supposed to fly straight, but instead it flew in loops or spirals.

   Do you think the customer (the person who hired you to make the plane) will be happy?

   No, they will probably be mad because you did not build what they wanted.

   Why do you think this happened? Could this problem have been prevented?

   Maybe you did not pay attention when the customer told you what they wanted, or maybe you did not test your plane after you built it.

3. Explain that today in class, you (the teacher) will be the customer and they (the students) will form paper airplane companies. As a customer, you will have some criteria for a good paper airplane. Criteria are like goals or objectives. They define what the paper airplane (or in general, the solution to any engineering problem) should do to be considered "good" or "successful." Each team will produce one final paper airplane design and demonstrate whether it meets the criteria. However, they will also face some constraints, or limitations. They will not have all day or as much paper as they want to make their planes. They will find out the details for the criteria and constraints in a few minutes.
4. Recommended: if you have a lot of students who have never made a paper airplane before, walk the whole class through building a simple design, one step at a time. You can use the basic or intermediate designs from our paper airplane instructions handout, which is available to help students get started with some different designs.

Explore (45 minutes)

1. Divide your students into teams of 3–4. If you have any students that you know are good at making paper airplanes, make sure you split them up. Let each team come up with a team name and write it on their worksheets.
2. Explain that there are a few rules to make sure everyone participates (this is to prevent one experienced student in each team from making and throwing all the planes). After deciding on a final design, each team will make and test four planes. Within each team:
   1. Every student must participate in making the final four planes. They can do this in an "assembly line" process (one student makes a fold, then passes it to the next student who makes another fold, and so on until the plane is done), or each student can make one plane. (Note for teacher: the assembly line process may be better for teams with varied skill levels. One student can start off with simpler steps like folding the paper in half, and more experienced students can complete the more complex folds).
   2. Students will take turns throwing the planes for a total of 12 throws (each of the four planes will be thrown three times). For teams of four students, each student will throw three times. For teams of three students, each student will throw four times.
3. Distribute an equal amount of materials to each team. Each team should have at least 12 pieces of paper for testing paper airplane designs. You can decide what quantities to use for any of the optional materials (e.g. one roll of tape, one pair of scissors, four paper clips).
4. Explain how your students will approach this as an engineering problem. Students can follow along on the worksheet, individually or in teams, to identify the criteria and constraints of the problem. You can use this worksheet as a formative assessment to measure their understanding.
   1. As a customer I want a plane that can fly as far as possible.
   2. I also want the plane to be reliable. I want to make sure that you did not just have one lucky throw or make one really good plane. To check this, I want your team to build me four planes and throw each plane three times, for a total of 12 throws, and measure how far they go. Then I want you to find the average distance for all the throws.
      1. Note: your students might not know what "average" means mathematically, or how to calculate it. It is sufficient for the students to have an intuitive understanding. If necessary, you can explain that an average is like a typical value when you have a bunch of numbers. For example, if you lined the whole class up from shortest to tallest, a person of average height would be in the middle. If you have one group of very tall people and one group of very short people, their average height would be about halfway in between (even if there is not one single person whose height is in the middle). Your students can record the distances and you can calculate the average for them.
   3. I also want a plane that is easy to manufacture. That way, if I decide that I want more planes, I can order them quickly. To check this, I want you to build four new planes in five minutes or less.
   4. You can only use the materials given to you by the teacher (no asking for more paper).
   5. Your team will only have 15 minutes to decide on a design.
   6. After deciding on a design, you will only have five minutes to decide how to build four of the planes. Will everyone on your team build one plane, or will you use an assembly line process?
5. Give the class 15 minutes to experiment with different paper airplane designs and decide on a final design for their teams.
   1. You can provide the paper airplane instructions sheet as a reference for each team. Point out that these designs are just examples; there is no guarantee that they are the best designs. Remind your students that they are engineers. Engineers design new things and improve existing things all the time. Encourage them to make at least one change or improvement instead of just using designs directly from the instructions.
   2. Encourage teams to test their designs by throwing the planes. Do not just pick a design because it is someone's favorite or somebody already knows how to make one.
   3. Keep students aware of the remaining time and make sure each team is on track to agree on a final design before time is up.
6. Give each team five minutes to decide how they will build four copies of their design. Remember that each student must participate in making the planes. They should write their team name and plane number (1–4) on each plane, but this does not count as a step (i.e. they cannot just assign one student to do the writing while everyone else folds). If they choose an "assembly line" process, they should decide who will make which folds. If they decide to have each student make one plane (note: in teams of three, one student will need to make two planes), they should make sure everyone knows how to make a plane by themselves.
7. Give each team five minutes to build four copies of their design.
8. Let each team show the customer the performance of their final design, and record their results on the student worksheet.
   1. Set up a tape measure on the ground and use it to measure the forward distance the plane travels (see Figure 2) in either inches or centimeters. If you want to avoid dealing with fractions or decimals, round to the nearest whole inch (or centimeter) when recording distances.
   2. Each of their four planes must be thrown three times, for a total of 12 throws.
   3. Each student in the team should make three throws (for teams of four) or four throws (for teams of three).
   4. Calculate the average distance for all 12 throws. Note: if your students have not yet learned how to calculate averages, you can do this step for them (see worksheet for instructions).

Image Credit: Ben Finio, Science Buddies / Science Buddies
Figure 2. How to measure forward distance the plane travels, from where it was thrown to where it lands.

Reflect (10 minutes)

1. Let each team show their final paper airplane design to the class and briefly explain why they picked that design.
2. Make a table like Table 1 on the board, and fill it in with the results from teach team.
   
   
   Swipe left to see more

   Team Name	Average Distance	Built four planes in under 5 minutes? (yes/no)

   Table 1. Example data table for class-wide results.

   Based on all the results, which team did the best job meeting the criteria?

   The team that had the longest average distance and was able to build all four of their final planes in less than five minutes.

3. You can use the student worksheet to ask students to reflect on the following questions individually (or in teams), or discuss them as a class and skip the last page of the worksheet.

   Why was it important to define criteria and constraints for our engineering problem?

   We had to define the criteria to make sure we built what the customer wanted. We had to know what the constraints were so we did not run out of time or materials when building our planes.

   Did you find any of the criteria or constraints hard to deal with? What problems did you encounter?

   Answers could include, for example, that they wished they had more paper to test more designs, more time to decide on a final design, and/or more time to build four copies. Maybe they felt it was difficult to build four planes with reliable performance (if one plane performed better than the others).

   If we did this activity again and you had more time or materials (fewer constraints), what would you do differently?

   Answers could include using different materials, doing some background research about successful paper airplane designs, more systematic testing of their designs, etc.

   Think back to the paper airplane I showed you at the very beginning of class. Using words you learned today, can you describe what was wrong with that paper airplane?

   That paper airplane did not meet the criteria for the problem. It was supposed to fly straight, and instead, it flew in loops.

Remember to see the variations section for suggestions to highlight other parts of the engineering design process.

Make Career Connections

Discussing or reading about these careers can help students make important connections between the in-class lesson and STEM job opportunities in the real world.

Aerospace Engineer

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Career Profile

Did you have fun designing and building planes? Do you want to come up with lots of crazy designs of your own? Aerospace engineers design and build real planes, and other flying vehicles like helicopters and rockets. Read more

Industrial Engineer

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Career Profile

Did you have fun figuring out the process to make your planes? Do you think you could figure out how to produce them faster or more efficiently? Could you turn your entire classroom into a plane-producing factory? Industrial engineers design and optimize the factories that produce things like planes, as well as household items like computers, cell phones, and refrigerators. Read more

Lesson Plan Variations

• There are several ways you can use this project to focus on other steps of the engineering design process. You can also go through the entire engineering design process in more detail. For example:
  • Background research: have your students do research about paper airplane designs online or using books. Are some types of designs more stable than others? What types of designs have held world records for distance? Are some easier to make or more reliable?
  • Test and redesign: this process was informal in this lesson. You gave your students 15 minutes to play around and decide on a design, but they did not necessarily do this systematically. Officially, they only tested one "iteration" of their design. Instead, have them formally test multiple iterations of their design. After completing the first round of tests, repeat the process: give each team 10 minutes to modify or improve their design and then test again. Keep iterating as time allows. Does the class-wide average distance get better with each successive round of iterations? Do more teams meet the time constraint of building the planes within five minutes? In other words, are the designs improving overall? What about the individual teams?
• Try designing a plane for accuracy instead of distance. For example, make the goal to throw the plane in as straight a line as possible (with the criterion that the plane must travel some minimum forward distance, like 3–4 meters). Mark a long, straight line on the floor with tape and throw the planes along this line. Measure the perpendicular distance to the line from where the plane lands (the horizontal dashed line in Figure 2). This distance should be as small as possible (ideally zero if the plane lands right on the tape, meaning it flew perfectly straight).
• You can easily turn this into a scientific method project. Have each team pick a single paper airplane design, but this time, pick a single variable to change (for example, adding fins to the wings, changing the angle of one of the folds, changing the angle at which they throw the plane relative to the ground, etc.). How does changing this variable affect the distance the plane flies? Be careful about control variables as well (e.g. which student makes or throws the plane).
• Try experimenting with paper airplanes outside. Do certain plane designs fly better in windy conditions than others? How do planes fly if you throw them into, along with, or perpendicular to the wind?