Abstract: A pneumatic aircraft tire has carcass plies and/or breaker plies which are reinforced by high modulus reinforcement cords embedded in a rubber composition that contains no free amines and has a 300% modulus of 12-18 MPa and a minimum tensile strength of 23 MPa as tested per ASTM D412, and a T90 of between 30 and 40 minutes at a reference temperature of 135 degrees C. as tested per ASTM D2084. The cords in the carcass plies and/or breaker plies have a tenacity of 6.6 to 8.2 g/denier, an initial modulus of 120 to 280 g/denier, an elongation at break of 8 to 18% and a shrinkage of not greater than 3%. Polyester reinforcement cords are preferred.