In this lesson, students will learn about kites and gliders and how these models can help in understanding the concept of flight. Students will design and build their own balsa wood models and experiment with different control surfaces. The goal of this lesson is for students to apply their existing knowledge about the four forces affecting flight and apply engineering design to develop a sound glider. They will also communicate the reasoning and results of any design modifications made.

Orville and Wilbur Wright were two early aeronautical engineers. When they designed their first airplane, they built balsa models and kites to test how well their airplane would fly. Modern engineers do the same thing when designing airplanes. Engineers today also use computers to test aspects of their designs before they build the real thing. This is less expensive, easier and quicker since they can learn from the mistakes on the small-size, inexpensive models as opposed to mistakes made on full-size, expensive airplanes. balsa wing shapes control surface control plane glider airplanes flight After this lesson, the students should be able to: Identify the four forces affecting flight. Describe the evolution of flight design through history. Explain why engineers build models before a final product. Give examples of how aircraft models can be modified to improve flight. What are different types of aircraft? Today we are going to talk about kites and gliders. How many of you have flown a kite before? What are the parts of the kite? (Answer: A basic kite has wings, a supporting structure, and a tail) Is a kite made from very light or heavy materials? (Answer: Usually light) Does a heavy kite fly well in little wind? (Answer: No, you need a lot of wind to lift a heavy kite.) How many of you have seen fancy a kite that performs tricks? How about kites that have multi-levels? Can the person flying the kite move the kite around a lot? Who thinks a kite is just a toy? Well kites are not just toys! They can be a good tool for learning about airplanes, and especially about glider flight! A glider is defined as any aircraft that flies without an engine. Engineers can learn a lot about the flight patterns of a glider by building a kite model of the glider first. They can hold it by hand (if it is small enough to control) and observe its flight patterns when they vary any number of components: the wing shape and size, its position on the kite's body, the structure of the entire body of the kite, and various tail assemblies. Early experimenters of flight built kites that resembled the glider or powered vehicle that s/he hoped to build later. Some of these kites were full-sized, resembling the glider or airplane they intended to fly later but using cheaper materials. Sometimes experimenters placed weights on the kite to observe how specific weight being carried would change the flight pattern. The Wright Brothers were among those who built several kites of increasingly larger size before they actually built their gliders and powered aircraft. They used the kites and model gliders to experiment with wing warping and how much weight a kite or glider could carry before failing. What can you learn from flying a kite? (Answer: You can learn about how much wind needs to be present to overcome weight (lift); how wind affects the way the kite flies; how to control the kite's movement to not crash.) What can you learn from building a glider? (Answer: You can learn about flight patterns, how control surfaces affect flight, how much weight a design can hold, how much lift is created by wing shapes, among many others.) Not all engineering is well thought out the first time around. Sometimes, the best designs are accidental. You are going to have an opportunity to use all of the information you have learned about aircraft flight to design and then redesign a balsa glider to increase its flight time and distance. Students have already learned about the four forces affecting flight and variables involved in the engineering design of airplane models. This lesson leads them further through the thought processes behind airplane design and invites them look at the historical aspect of airplane design through the design of simple gliders. Students also have the opportunity to discuss some implications of historical and modern aircraft. The social history of flight is pretty diverse. People have always looked to the heavens to determine the cycles of seasons, agriculture and life. Humans have dreamed about being able to fly to the heavens just as birds do. Mythological stories tell us about birds and other winged creatures that fly Gods and their chariots through the sky and in and out of the clouds. Humans had the desire to emulate the Gods by creating flying machines. As knowledge of the Universe grew, the connection between the heavens and mythological flight faded, and the desire to achieve flight remained. The ancient Chinese reportedly tried to sail through the air by attaching themselves to kites, one of the most significant inventions leading to flight. Other flight pioneers such as Leonardo da Vinci and the Wright brothers have made modern flight a reality. Throughout history and into modern space exploration, individuals have taken steps towards this dream, often with injuries and sometimes with fatal outcomes. Nevertheless, efforts continue and there is no turning back. Aviation has become part of the mindset of our world. Air flight has changed society, from the development of small, crude airports servicing short flights to large, state-of-the-art terminals services quick, convenient travel through the air to far away destinations. You can see the influence of flight in literature, art, comics, music, movies and television. Space flight has always been a desire of humans as well, and space aviation is another large industry, dealing with both known and unknown realms. Over thousands of years, thoughts of flight have been an underlying force in social development. From one point of view, flight has been very beneficial, bringing people closer together, allowing a new job market for people with flight-related talents, helped inspire creativity, and opened up a world of possibilities to exploration outside of Earth. However, some would argue that flight has been detrimental as well, as it has made warfare more intense, can be attributed to an increase in pollution, and is costly, taking money from other areas of need. an aircraft similar to an airplane but without an engine. a light frame covered usually with paper or cloth, with a stabilizing tail, and designed to be flown in the air at the end of a long string. a standard that an experimental model is measured against. light weight wood that is easily manipulated in making airplanes. the amount of space between two things, objects or points. a plan, sketch or outline made to serve as a guide or pattern. Balsa Glider Competition Discuss the students' glider designs. What modifications did you make to your glider? Did it make the glider work better? What could you do next time to make the glider perform even better? Do you think it is a good idea for engineers to design glider models before they build a real glider? Why or why not? Try to encourage reasoning based on the knowledge gained from the previous lessons. Students should share their results as a class and make connections. Brainstorm: Encourage wild ideas and discourage criticism of any ideas. Develop a class list of different aircraft or things that fly. They can be toys, models, types of airplanes, helicopters, etc. Question/Answer: Ask students questions and have them raise their hands to respond. What can you learn from flying a kite? (Possible answers: You can learn about how much wind needs to be present to overcome weight (lift); how wind affects the way the kite flies; how to control the kite's movement.) What can you learn from building a glider? (Possible answers: You can learn about flight patterns, how control surfaces affect flight, how much weight a design can hold, how much lift is created by wing shapes, etc.) True or False: All of the best engineering designs come from well thought out plans. (Answer: False, not all engineering is well thought out the first time. Sometimes, the best designs result from an accident that happened during the experiment that was actually better than the original idea.) Review the concepts from the previous lessons that can affect flight. What is the affect of weight on flight? What do control surfaces have to do with how an airplane flies? Are bigger wings better or worse for a glider? Venn Diagram: Have students create a Venn diagram to compare and contrast the different types of aircraft that have been discussed. See http://www.venndiagram.com for ideas/diagrams. Have students draw three overlapping circles. Label one circle with kite, the second circle with glider and the last circle with airplane. Have the students list all of the observations the three types of aircraft have in common in the overlapping sections and observations of what is different for each aircraft in the outside circle sections. Class Debate: Split the class into two groups. Have one group argue for (agree with) the topic and one group talk against (disagree with) the topic. Give the groups a few minutes to come up with their arguments before the class debate. Topic: The flying machine (Aircraft) has changed society for the better. (As examples: students that are for the topic can discuss transportation advances, and students against the topic could discuss the pollution effects of flight or increased abilities of warfare.) Cartoon Character: Cartoon characters such as Bugs Bunny have often been sent into flight missions to escape a situation. Create your own cartoon sketch of a character in flight. Your character could be in a glider or airplane, or maybe hanging from a kite. Make sure to label one of the four forces (drag, lift, weight or thrust) acting on the character and have your character saying something about how the force is affecting them. Have the students research other early models of aircraft and the engineers/inventors who developed them. Students can research kite-flying tricks. How can the tricks accomplished by different kites be explained in terms of the four forces affecting flight? Students can try to re-design their gliders for other factors, such as cargo. Whose glider can carry the most pennies and still fly a distance? http://www.turnertoys.com/G1/balsa_model_airplanes3.htm