Rutting is a major distress mode for airfield asphalt pavements. In Japan, polymer-modified asphalt (PMA) mixtures are often used in the surface course to reduce rutting. However, severe rutting can still occur at intersections of taxiways and at the ends of runways, where aircraft stops temporarily or taxi. Although concrete paving is considered to be an effective countermeasure against rutting, tight time and space constraints make it difficult to apply where it is needed because most airports are unable to provide alternate runways or taxiways for takeoff and landing while the pavement is curing. Thus, the development of materials that have a higher resistance to rutting and overnight serviceability remains a technical challenge. The authors have developed a high-stability asphalt (HSA) mixture. The newly developed asphalt is composed of a special thermoplastic resin, and an asphalt modified with styrene-butadiene-styrene block copolymer (SBS). It has a high resistance to rutting, and oil and can be applied using the same construction procedure used for conventional hot mix asphalt mixtures in Japan. The unit price of the HSA mixture is about three times as high as that of the straight asphalt (SA) mixture. Although the rutting resistance under vehicle loading has been found to be equal to a semi-flexible pavement material, which is an open-graded asphalt mixture filled with a cement grout, little is known about the durability such as the rutting resistance and groove stability under aircraft loading. In order to investigate the durability of the HSA mixture, laboratory tests were carried out involving simulated aircraft loading. A full-scale loading test was then performed in order to confirm the results of the laboratory tests. The present paper describes the results of a series of tests performed in order to clarify the fundamental properties of the mixture under aircraft loading.