More on a Spiral Approach to STEM Learning

In a previous post, I discussed how our integrated curriculum in the Academy of Aerospace and Engineering uses a spiral approach to learning. This means we revisit concepts in different classes and over time so that students repeatedly get a chance to solidify their learning. One recent example of this approach is in how the students are learning about aircraft propulsion.

In science and aerospace science, the 7th graders first learned about the forces of flight, including thrust, the force of propulsion. They also studied Newton’s Laws and learned that the Third Law explains how thrust works for both propellers and jet engines. Then they studied types of engines, including reciprocating (piston) engines and jet turbine engines. Finally, Ms. Garavel tasked them to do an engineering design project to redesign the propeller on a Guillow Strato Streak rubber band powered airplane. Each student crew (group of 4 students) is designing and 3D printing their propellers and will test them on the Guillow model airplane this week. In two weeks, the academy is going on a field trip to Pratt & Whitney and to the New England Air Museum to learn firsthand about jet engines and propulsion systems. Therefore, the 7th grade students have had repeated lessons where they learned about Newton’s Laws of motion, the forces of flight, and propulsion systems. Here is a photo of our two 3D printers with two different crews’ propeller designs on the build plates and a Guillow Strato Streak between them to show the original propeller that they are redesigning:

IMG_4307

The 8th graders have spiraled back to learn more about aircraft propulsion systems in a two significant activities. First, I assigned a project where each 8th grade crew plays the role of an engineering team in an airline company in which the CEO has tasked them to re-engine the fleet with new Pratt & Whitney Pure Power geared turbofan engines, then to re-imagine a use for the old jet engines. For the first task, the students had to research and learn about the new Pure Power engines, then select the right model for each airliner and present their plan back to the CEO (played by Mr. Dias, our Principal). For the second task, the students used the engineering design process to research and brainstorm a new use for the old jet engines. The students will present their idea in the form of a business plan back to the CEO again this Tuesday. The 8th graders are also doing a more hands on project, as I assigned them theĀ Electric Cargo Airplane Challenge developed for high school students by theĀ American Institute of Aeronautics and Astronautics (AIAA). This is a tough challenge where students design and build a model airplane powered by one or two (their choice) 6-volt electric motors with propellers. The students must build the airplane from scratch, though they may use stock propellers and wheels. The electric motors are also provided to them. The electricity is supplied by a wire to the airplane that is connected to a heavy pole around which the airplane flies. The thrust is the same for every crew, since they all use the same power source, so the real challenge is to minimize weight and drag to effectively increase the net force (thrust) available.

I tried this project for the first time last year, and none of the six crews were able to really get their airplanes to fly, except for one crew that kept working on the airplane and finally got it flying after the project was officially finished. I shared this experience with my students this year, and they listened and improved on last year’s performance — so far, all three crews that have done the project have successfully flown their airplanes after some redesigning. The other three crews will start building their airplanes this week. We will have a fly off of all six crews in about three weeks. Here are photos of the first three crews with their airplanes, and some screen shots of a video of the first successful airplane to fly (the airplane of Crew 4, the second crew shown here):

IMG_8505BIMG_8505AIMG_8505CElectric Airplane 1Electric Airplane 2Electric Airplane 3

When we did the flight tests of these three aircraft this past week, we had some college engineering students from UCONN’s chapter of AIAA visiting us. They presented to the students about UCONN’s engineering program, and they observed and mentored the academy students. After they watched this flight test, and saw the 7th graders busily working on their 3D printed propeller project, one of the AIAA students told us, “I can’t believe how much these students know and what they are capable of doing here.” He was surprised that middle schoolers knew anything about aerodynamics or propulsion or that they could do engineering projects. The reason this is possible is because of our integrated curriculum and spiral approach to learning.

Spiral Approach to STEM Learning

Students at the Academy of Aerospace and Engineering get to learn topics that most other students may not see until late in high school or in college, if at all. Examples include aerodynamics, astrophysics, aircraft and rocket design, and many other aerospace and engineering topics. While our school district promotes mastery based learning, which we use in our basic science and math classes, it is unrealistic for a middle school student to achieve mastery in aerodynamics or other advanced STEM (science, technology, engineering, and math) topics–this is where a spiral approach makes sense.

What do these terms mean? Mastery based learning is the idea that students should learn a subject incrementally and achieve mastery, or a defined level of understanding and competence, before moving on to the next increment. We use this approach in both our science and math courses where we work with students to fully understand a topic before we move on to the next topic, and where each topic is defined by one or more state curriculum standards. In contrast, spiral learning is when students learn a subject at some level, then move on, but return later to learn more about the subject at a deeper level. Depending on the subject and the grade of the student, mastery of the subject may or may not be appropriate. This spiral approach is perfect for our elective courses in the academy where we want to repeatedly expose students to higher level concepts that are used in colleges and industry so that the students can envision themselves succeeding in these subjects some time in the future. The majority of US students do not pursue science or engineering, and one big reason is because they have no idea what a scientist or engineer does. By exposing students to firsthand experiences where they do science and engineering tests and build things using an engineering design process, they can see themselves becoming scientists and engineers someday. Using a spiral approach makes these types of experiences more meaningful, as the students see themselves improving in their knowledge and competence over time.

One example from the past week in the academy is a spiral approach to aerodynamics. The seventh graders did a basic project making a FPG-9 (a glider made from a 9-inch foam plate), then flight testing it outside. The glider has a rudder and elevons (combination ailerons and elevator), and students had to do an inquiry activity to see how the flight controls work. Later in the week, the students started an activity where they build a model aircraft or spacecraft, research it, and present their model and report to the class. These activities connected to what they were learning in science and in their flight simulator lessons. Meanwhile, the 8th graders, being more advanced in the academy program, are using a GDJ Flotec wind tunnel this week to measure the relative drag of the model rockets they designed and built over the past two weeks. Their task is to make the fastest possible rocket powered by an Estes A8-3 engine. The students are studying forces in science and vectors in geometry, so we put that together to discuss the net force on the rocket, and the students understood they wanted to reduce the weight and drag as much as possible in their designs. After wind tunnel testing, one crew repeatedly refined their rocket and cut the drag almost in half. We launch in the coming week. I do not intend for these students to achieve mastery in aerodynamics, but by periodically doing fun activities involving aerodynamics, and by making each activity more challenging than the last one, the students eventually achieve a high level of understanding in a complex STEM topic.

Here are photos of the 7th graders with their FPG-9s and models:

IMG_8170IMG_8172IMG_8173IMG_8180IMG_8181IMG_8182IMG_8184IMG_8176IMG_8177IMG_8178IMG_8179

Here are the 8th graders using the wind tunnel and photos of each crew with their rocket:

IMG_4128IMG_4129IMG_4130IMG_4132IMG_4135IMG_4136IMG_4137IMG_4138IMG_4141IMG_4142IMG_4143IMG_4144IMG_4145IMG_4146