Pneumatic tire for airplanes

In pneumatic tire for airplanes comprising a plurality of circumferentially extending grooves and a plurality of circumferentially extending ribs separated from each other by means of said grooves, the improvement comprising, a pair of circumferentially extending grooves each arranged at a shoulder portion of the tire and substantially symmetrically and equally spaced apart from a crown center of the tire, the distance between said circumferentially extending grooves arranged at the shoulder portions being, when the tire is inflated, from 50% to 95% of a tread width and dividing a tread portion of the tire into a center zone and two shoulder zones, a sectional contour defining an outer surface of said tread portion being a continuous curve in both the center zone and the two shoulder zones, and the outer surface of the tire being protruded at both said shoulder zones from said circumferentially extending grooves arranged at the shoulder portions of the tire toward the outside thereof by a step projected from said tread portion even after said tire is inflated and having a level difference when the tire is uninflated from 0.5 mm to 6 mm, whereby a ratio of the load subjected to said center zone to the load subjected to said two shoulder zones is reduced, thereby improving the high speed durability of the tire without sacrificing the wear resistance thereof.