Civil Air Patrol’s ACE Program Paper Airplanes Grade 4 Academic Lesson #3 Topics: flight, movement, cause and effect (science) Length of Lesson: 30-50 minutes Objectives: • Students will define and demonstrate the rotational movements of pitch, yaw, and roll. • Students will identify control surfaces of an airplane (i.e. aileron, elevator, rudder) and explain how adjusting the control surface affects the rotational movement of the plane. • Students will experiment with variables that control an airplane’s movement by making and flying a paper airplane. National Science Standards: • Content Standard A: Science as Inquiry - Abilities necessary to do scientific inquiry - Understandings about scientific inquiry • Content Standard B: Physical Science - Motions and forces • Content Standard E: Science and Technology - Abilities of technological design • Unifying Concepts and Processes - Form and function Background Information: In summary, an aircraft’s surface controls allow a pilot to adjust and control the aircraft’s flight attitude (the position of the aircraft). An aircraft can rotate around three axes of motion: 1. The vertical axis passes through the plane from top to bottom. Rotation around this axis is called yaw. The control surface on an airplane that controls yaw is the rudder. 2. The lateral axis passes through the plane from wingtip to wingtip. Rotation about this axis is called pitch. The control surfaces that control pitch are the elevators. 3. The longitudinal axis passes through the plane from nose to tail. Rotation around this axis is called bank or roll. The primary control surface for bank is the ailerons. CAP’s ACE Program (2011) 41 The background information that follows is from NASA Quest at http://quest.arc.nasa.gov/aero/planetary/atmospheric/control.html. An airplane has three control surfaces: ailerons, elevators and a rudder. These control surfaces affect the motions of an airplane by changing the way the air flows around it. The ailerons are flap-like structures on the trailing edge of the wings -one on each side. When the pilot moves the control stick to the right, the right aileron will tilt up and the left aileron will tilt down. This will cause the airplane to roll to the right. When the pilot moves the control stick to the left, the left aileron tilts up, the right aileron tilts down and the airplane rolls to the left. This happens because as the aileron tilts downward (effectively increasing camber) more lift is created and the wing rises. As it tilts upward, less lift will be created and the wing will lower. If the wing of one side of the airplane rises and the other descends, the airplane will roll towards the side with the decrease in lift. CAP’s ACE Program (2011) 42 The elevators are also flap-like structures that are mounted on each side of the horizontal stabilizer. As an airplane flies in its proper orientation and level to the horizon the pilot uses the elevator to control the pitch of the nose. That means the elevator controls the nose's motion of up and down. When the pilot pushes the control stick forward, the elevators tilt downward -this is called pitching down. When the pilot pulls the control stick back, the elevators tilt upward, the tail goes down and the fuselage pitches nose-up. When the elevator tilts downward more lift is created (like the ailerons) and the tail rises. When the elevator tilts upward, less lift is created and the tail descends. The rudder is located on the vertical fin. The rudder controls the motion of yaw. Yaw causes the airplane's nose to move sideways to the left or right. The two rudder pedals are located at the pilot's feet. When the pilot pushes on the right rudder pedal, the rudder tilts to the right and the airplane yaws nose-right. When the pilot pushes on the left rudder pedal, the rudder tilts to the left and the airplane yaws nose-left. Again this is due to lift. However, the direction of this lift force is different than the lift force that causes the airplane to ascend. When the rudder tilts to the right, more lift is created on the right, which lifts or pushes the vertical stabilizer to the left. This, in turn, causes the airplane to yaw nose-right. The opposite motion occurs when the rudder tilts to the left. The thinner the atmosphere the slower the reaction of the airplane to its control surfaces. Airplanes flying at fast speeds in the lower atmosphere react more quickly to a change in the control surfaces than airplanes flying at extremely high altitudes at the same speed. That's because there are fewer air molecules to disturb. This becomes even more important when flying airplanes on planets with atmospheres that are less dense than Earth's atmosphere. CAP’s ACE Program (2011) 43 (Info and picture below from http://spaceday-cert.donet.com/media/documents/SpaceDayToolkit.pdf) Pilots use different terms to describe the particular ways an aircraft moves forward: Pitch: Aircraft nose moves up or down Roll: One wing of aircraft tips up while the other tips down Yaw: Nose of airplane moves left or right while remaining level with the ground Pilots use several control surfaces (movable sections on the aircraft’s surface) to better direct an aircraft’s movement. These include: Elevator: Section on horizontal part of tail that controls pitch Aileron: Section at rear edge of wing near tip that controls roll Rudder: Section attached to vertical part of tail that controls yaw CAP’s ACE Program (2011) 44 Materials: - model of airplane for teacher use – possibilities include: a CAP paper airplane; a balsa plane with small “sticky” notes placed in the appropriate positions to represent the rudder, ailerons, and elevators; a Styrofoam model usually found at a discount or toy store; Cardstock or paper and tape can be used to make moveable control surfaces on the teacher demonstration model, if the model does not have moveable parts. - CAP paper airplane for each student (copy included) (Class sets can also be ordered from CAP by going to eServices at https://www.capnhq.gov . Click “CAP Materials,” “Submit Order,” and then “AE Materials.” Locate CAP paper airplanes and enter the quantity “1” for a set of 25. Enter your reason for your order on the right.) - overhead projector and transparency of the airplane picture and information on the previous page (or student handouts of the previous page) (optional) - scissors and tape Lesson Presentation: 1. Show a model of an airplane. Ask students to share what they know about airplanes in terms of their parts and how they fly. Students should easily identify the cockpit, where the pilot flies the plane; the propellers or jet engines, which generate thrust; the wings, which create lift, the tail (which includes a vertical and horizontal stabilizer), which helps stabilize the plane; and the fuselage, which is the long, hollow main body of the plane stretching from front to back and includes the area for passengers and cargo. 2. Ask students to describe movements an airplane can make while traveling in the sky. 3. Show a model of an airplane and discuss and demonstrate the rotational movements of pitch, yaw, and roll. (Consider showing or distributing student handouts of the airplane picture and explanations on the previous page.) 4. Next, using the model, identify and discuss the control surfaces (i.e. rudder, aileron, elevator) that are responsible for each movement (pitch, roll, and yaw). (If you are using the CAP paper airplane, the ailerons and elevators have been combined, resulting in the term “elevons.” The elevons control both pitch and yaw.) 5. Tell students that they will make a paper airplane and that paper airplanes are examples of gliders. Ask students to define glider. (an aircraft that has no power source, such as an engine, to continually generate forward motion/thrust) 6. Distribute the CAP paper airplanes and guide students through the process of making the paper airplane. 7. Once students have finished making their paper airplanes, call out rotational movements (pitch, yaw, roll), and have students demonstrate the movement with their paper airplane. CAP’s ACE Program (2011) 45 8. Show students how to make and use the control surfaces for their paper airplane. Two slits are cut in the rear surface of each wing to make bendable tabs, as indicated by thin blue lines on the rear of the wing. Since the paper airplane has a combined “wing” and “horizontal stabilizer,” these bendable surface controls are actually called elevons, meaning the aileron and elevator are combined. When the two bendable elevon tabs are in alternating positions, roll is affected. When the two bendable elevon tabs are both up or both down, it affects pitch. If the vertical stabilizer on the tail of the paper airplane has 2 slits to cut to make a control tab that can move side to side, this will control the “yaw” of the plane, or the movement left or right. This control tab is called the rudder. (These adjustments may not be able to be made on balsa planes without breaking the planes. Using cardstock or paper to make such control surfaces on the balsa planes may work.) 9. Have students experiment with their planes, adjusting the control surfaces to adjust the plane’s attitude (position in flight). Consider having a target or a finish line for students to use while experimenting with flight. Summarization: Have the students discuss what makes their airplanes move the way they do. This will aid in understanding of the concepts. The same is true when they can explain how to get their planes to reach the target.