Abstract: A heavy duty high speed cross ply tire has a carcass composed of at least one aromatic polyamide fiber cord ply, the product T.sqroot.D of the cable twist number T (turns/10 cm) of the belt cord and the square root of the total denier number D (deniers) of the cord is 2.466.times.10.sup.3 to 3.036.times.10.sup.3 and the elongation E (%) at breakage of the belt cord divided by the total denier number D is 7.78.times.10.sup.-4 to 12.22.times.10.sup.-4.

Abstract: A tire for an airplane comprises a pair of bead cores; a carcass fixed around the pair of bead cores with its ends being turned up, the carcass having cords arranged at an angle of 60.degree. to 90.degree. with respect to an equator plane of the tire; a belt layer having cords arranged outside the carcass at an angle of 0.degree. to 30.degree. with respect to the equator plane of the tire; and a band arranged above the belt layer. The band has cords which have a higher modulus of tensile elasticity than that of the cords of the belt layer. The cords of the carcass and the belt layer are made of organic fibers having a modulus of tensile elasticity not greater than 1,000 kg/mm.sup.2. The tire may include a bead apex and a reinforcement layer positioned outside of the head apex. The reinforcement layer extends from a bottom of each of the pair of bead cores to a side wall of the tire.