Learning Objectives

1. Understand common aircraft skin types and their history
2. Get to know common types of control surfaces of an aircraft, then try to modify your RC Plane’s control surfaces to improve its performance
3. Understand different landing gear types and their suitable use case scenarios, and try to make some modification on your RC plane

3.1 Common Aircraft Skin Materials and Their Properties

The skin of an aircraft is its outer covering, which must handle aerodynamic loads, protect internal components, and often contribute to the overall structural strength. The choice of skin material has a huge influence on weight, durability, repairability, and flight characteristics. In the world of RC planes, we borrow heavily from full-scale aviation history, but we also have access to materials uniquely suited to small, lightweight models.

3.1.1 A Brief History

• Fabric & Dope (1903–1930s): The Wright Flyer used unbleached muslin. Soon after, doped linen became standard. The fabric was stretched over a wooden frame and coated with cellulose nitrate “dope” to shrink it tight and make it airtight. This gave a lightweight, easily repairable surface but offered little structural rigidity and degraded under sunlight.

  

• Stressed-Skin Aluminum (1930s–1960s): The Boeing 247 and Douglas DC-3 pioneered smooth, all-metal skins made of aluminum alloys (like 2024-T3 Alclad). The skin was riveted to a metal frame and carried part of the load – a “semi-monocoque” structure. This allowed higher speeds, better aerodynamics, and all-weather operation.

  

• Composite Skins (1970s–present): Fiberglass, carbon fiber, and Kevlar® (aramid) became common in sailplanes, then in airliners (Boeing 787, Airbus A350). Composites can be formed into complex curves, have excellent strength-to-weight ratios, and can be engineered to be anisotropic (strength tailored to load directions).

  

• Foam and Film (RC and Light Aircraft): Moving from reality to the realm of model aircraft -expanded foams (EPP, EPO, EPS) dominate because they are light, cheap, and easy to mold.

  

• Wood and shrink-wrap film (RC and Light Aircraft): Balsa wood covered with heat-shrink plastic film (Monokote, Ultracote) mimics the fabric‑and‑frame tradition at micro scale.

  

3.1.2 Key properties for choosing aircraft skin for your build

• Weight: Heavier skins increase wing loading, stall speed, and required power.
• Stiffness/Flexibility: A skin that twists too easily can cause control reversal or flutter. Too stiff and it may crack on impact.
• Durability: Resistance to hangar rash, UV light, moisture, and grass stains.
• Repairability: Foam can be glued; film can be patched; composites require more skill.

3.1.3 Common RC Skin Materials choices for RC toy planes