INTRODUCTORY: AERODYNAMICS Back
In this session, participants will learn about the forces that act on an airplane in flight, as well as the primary control surfaces of a plane.
- Exploring, Aviation
- Exploring, Engineering & Technology
- US Department of Education, STEM
- US Department of Education, Transportation
By the end of this session, participants will be able to:
- Point out on a model airplane the forces that act on an airplane in flight.
- Explain how an airfoil generates lift, how the primary control surfaces (ailerons, elevators, and rudder) affect the airplane’s attitude, and how a propeller produces thrust.
- Demonstrate how the control surfaces of an airplane are used for takeoff, straight climb, level turn, climbing turn, descending turn, straight descent, and landing.
It is highly recommended that this activity be conducted at a real airplane parked on a ramp or in a hangar. If an airplane is not available or is not feasible, use a remote control model airplane that has all the required surfaces and controls. If a model plane is used instead of a real plane, the size of the group should be reduced.
- Airplane(s) or remote control model airplane(s)
- Pens or pencils (one per participant)
- Angles of Attack activity sheet (one per participant)
- Aerodynamic Forces in Flight activity sheet (one per participant)
- Aerodynamics Wrap-Up activity sheet (one per participant)
: Text in italics should be read aloud to participants. As you engage your post in activities each week, please include comments, discussions, and feedback to the group relating to Character, Leadership, and Ethics. These are important attributes that make a difference in the success of youth in the workplace and in life.
In this session, the Advisor walks around the plane, pointing out various aerodynamic features such as the airfoils and control surfaces. The emphasis is on aerodynamics, with a focus on the stated objectives. The Advisor should ask questions throughout rather than simply lecture. The simple question “Why?” can often promote discussion and further questions.
Before beginning, discuss safety. Tell participants to watch where they’re going, move slowly around the airplane, watch their heads, watch for sharp edges, never touch the propeller, etc. Talk about the propeller and how it can get started on its own. Tell the participants not to touch anything unless you say it’s OK.
Discuss Bernoulli’s principle early in the session, and pass out the Angles of Attack activity sheet. Explain why an airfoil creates lift. A good demonstration of lift is to cut a half-inch strip from a piece of 8.5-by-11-inch paper. Hold the paper to your chin, hanging down, and ask participants to predict what will happen when you blow. Did they expect the paper to rise toward the blown breath?
Starting at the propeller, point out that an aircraft has many airfoils on it. Say: One of them you’re staring at, and it’s not a wing. What is it? Point out the propeller and how it is shaped like an airfoil, and explain how it produces thrust. Ask: If the prop always spins in a clockwise direction, why does the plane want to turn left? (Imagine the prop on the end of a boat. Spinning it makes the boat want to move toward the right. Because the prop on a plane is in front, not in back, it wants to go toward the left.)
Working from the front of the plane to the back, point out all airfoils and controls. Point out and discuss the propeller, wing, stabilizer, elevator, and trim tab.
Discuss stalls. Ask: What causes the plane to not fly? (The interruption of the airflow over the wing. Flat on bottom and curved on top is important. Changing the shape of the airfoil for any reason—including icing—changes the plane.)
Aerodynamic Forces in Flight
Pass out the Aerodynamic Forces in Flight activity sheet, and discuss how the four forces (lift, weight/gravity, thrust, and drag) act in flight.
Discuss the following:
- Slipstream, airflow over a wing, angle of attack, and turbulence.
- How the power setting affects the airplane’s attitude and how it is used to aid flight.
- How to make sure everything is configured for takeoff.
- With their arms out at their sides, have participants simulate, using their hands at different angles, what happens to the ailerons in a right-hand turn and a left-hand turn.
- The turn coordinator and the bank and slip indicator on the instrument panel. Demonstrate how the ailerons and rudder are used in coordination to turn the plane. Explain why slips and skids are bad, and how stalls during uncoordinated flight can lead to spins.
- Aerodynamic differences between a level turn and a climbing turn, and the tendency to lose altitude in a turn and why.
- Weight, balance, and the center of gravity and how these are planned for before a flight begins. This is part of the preflight and must include baggage, weights of all passengers, and any cargo. Discuss the calculations, why this is such an important part of flight planning, and why having too much overall weight is bad. Questions like “What happens when too much weight is forward or backward?” can help prompt participation.
Describe density altitude, explaining that hot weather and humid skies rob the airplane of lift and thrust. Use Aspen, Colorado, as an example. Density altitude is not a huge issue in flat Midwestern cities but can be a very big issue elsewhere.
Have students complete the Aerodynamics Wrap-Up activity sheet and answer any questions they may have.
Tips and Options
- Close the airplane doors and take off the control lock. When using the yoke and rudder pedals to control the wing and tail surfaces, participants may get distracted. Stay outside and manipulate the controls by moving them manually from the outside.
- If possible, have someone in the cockpit work the ailerons while the group watches them go up and down.
- If possible, have someone in the cockpit work the rudder to demonstrate what happens when the right or left foot pedal is pressed.
- If there is time and the group is small and well-behaved, let participants take turns sitting in the cockpit. Let them manipulate the yoke and rudders.
- Because girls tend to be more hesitant to participate in these activities than boys, try to engage the girls by asking questions, letting them manipulate the plane’s surfaces, and having them use their arms to simulate wing activity.
Some sample questions are below. They are designed to help the participants apply what they have learned to their own interests. You are welcome to use these questions or develop your own questions that relate to your post or specific focus area.
- If you push one aileron down, where does the plane want to go?
- Why do ailerons move in opposite directions?
- If you pull the rudder to one side, where does the plane want to go?
- If you pull the elevator up, where does the plane want to go? What if you push it down?
- Why do you think both flaps move in unison?
Content for this session provided by Youth Aviation Adventure (http://youthaviationadventure.org).
ADVISOR AND OFFICER REVIEW
After the meeting, address the following:
- Identify what was successful about the meeting.
- Identify what needed improvement.
- Schedule an officer and Advisor planning meeting to prepare for the next post meeting or activity.
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