The presence of surface contaminants on the wing leading edge of aircraft can expedite boundary-layer transition from laminar to turbulent. For aircraft wings to maintain natural laminar flow and reduce skin-friction drag, it is important to ensure their surfaces remain free from contaminants and/or insects. Japan Aerospace Exploration Agency has recently developed a method for maintaining laminar flow over wings. It involves the application of hydrophilic coatings on wing surfaces, which can be subsequently washed clean with water. These coatings prevent insects from adhering to the wing surface. The results of the coupon and ground tests performed in this study reveal that compared to conventional aircraft coatings, the proposed hydrophilic coatings demonstrate washabilities improved by up to 20%.