In the aviation industry, the process of de-icing is critical for stable flying because of the occurrence of airplane icing. To solve the icing problem, an electrical heating system is applied for airplane de-icing. Among the materials used in the electrical heating system, carbon-nanotube polymer composites are appropriate for an ice-prevention system owing to their rapid heating properties and flexibility. In this study, we fabricated a flexible carbon-nanotube/polydimethylsiloxane composite with a high content of carbon nanotube (20 wt%) for airplane de-icing. The high-load carbon nanotube composite was fabricated using a three-roll milling method, resulting in uniform dispersion of carbon nanotubes in the polymer matrix. The carbon nanotube/polydimethylsiloxane composites exhibited uniform and stable heating performance (from room temperature to 100 °C for 25 s without thermal aggregation). In addition, the carbon nanotube/polydimethylsiloxane composite is suitable for application to the curved surface of airfoils. For the de-icing experiments, a small airplane wing consisting of carbon nanotube/polydimethylsiloxane composite as a heating unit was fabricated with a scale ratio of 15:1. We conducted electrical heating and de-icing experiments using the developed airplane-wing system for actual anti-icing/de-icing applications.