Image
Once a winning design is chosen, it is time to start refining. Without being too critical, point out areas where major design flaws are present. Common areas to improve include stubby wings, insufficient area on the horizontal or vertical stabilizer and the wing located in a position that is difficult to achieve proper center of gravity. Try and give the aircraft as much wing area as possible without significantly altering the design.
Scale Drawings
After the design modifications have been considered, have the students make accurate top and side view drawings of the aircraft on two pieces of graph paper. Explain the concept of scale and how it relates to the design process. Include the location of the wing spar and the control surfaces in the drawing.
The Metro (above) is a low wing airplane that takes design cues from small, transport category commercial aircraft. It is an excellent flying model with no adverse flight characteristics. The Metro flies smoothly upright and given some space, is capable of mild aerobatics. Handling qualities are improved with a small amount of elevator to flap mix. Flights in a schoolyard or on a baseball diamond are no problem for an intermediate level RC Pilot. The Metro was the most straightforward design in our project.
The Shark is a low wing airplane with a radical trailing edge sweep. The front bears resemblance to the Bell X-1. It is an excellent flying model with no adverse flight characteristics. The shark is capable of tight turns and excels in higher speed aerobatics. Flights in a schoolyard or on a baseball diamond are no problem for an intermediate level RC Pilot. The Shark had the most radical wing design in our project. On-board video footage highlighted the sharp angle of the nose and captured the action of the ailerons as the aircraft was put through its paces.
The Beluga is a cartoon-like aircraft with massive side area. It has some bad aerodynamic qualities that are caused by this feature. The Beluga must be kept in upright, coordinated flight. Sideslip angle will cause the horizontal tail to become ineffective. The result will be a pitch up, uncommanded yaw and departure from controlled flight. The Beluga can successfully be flown in a playground or on a baseball diamond by an intermediate level RC Pilot as long as coordinated flight is maintained. The Beluga was the most challenging aircraft to fly in our group of designs.