T-4 Sotka The intent of this volume is to detail the Soviet Union’s Mach 3+ capable Sukhoi T-4 Sotka hypersonic missile carrier/Airborne Reconnaissance System designed and developed in the late 1960’s and early 1970’s as a conventional and nuclear counter to enemy aircraft carrier battle groups threatening Soviet territory. Prior to the programs cancellation in 1975, a single T-4 aircraft entered flight testing. The volume covers the genesis, design, development of the T-4 and the X-45 hypersonic missile armament and an overview of the flight tests of the former, which were conducted in the period August 1972 through mid-January 1974 when the program was suspended. Discussions of the various unofficial infighting within Sukhoi and disagreements between the heads of the various design bureaus of Sukhoi, Tupolev and Myasishchev are avoided - these are mere tangents that are not conducive to the aim of the volume and divert from the detail of the T-4 Sotka aircraft program as designed, built and flown, and the X-45 armament intended for the Sotka.