with the main landing gear in the wing glove rather than in large pods. 211 Tu-22M2 were built from 1972 into 1983. The Tu-22M2 had a top speed of Mach 1.65 and was armed most commonly with long-range cruise missiles/anti-ship missiles, typically one or two Raduga Kh-22 anti-shipping missiles. Some Tu-22M2s were later reequipped with more powerful NK-23 engines and redesignated Tu-22M2Ye. Tu-22M3 The later Tu-22M3 (NATO: Backfire-C), which first flew in 1977, introduced into operation in 1983 and officially entered service in 1989, had new NK-25 engines with substantially more power, wedge-shaped intake ramps similar to the MiG-25, wings with greater maximum sweep and a recontoured nose housing a new Almaz PNA (Planeta Nositel, izdeliye 030A) navigation/attack (NATO ‘Down Beat’) radar and NK-45 nav/attack system, which provides much-improved low-altitude flight. The aerodynamic changes increased its top speed to Mach 2.05 and its range by one third compared to the Tu-22M2. It has a revised tail turret with a single cannon, and provision for an internal rotary launcher for the Raduga Kh-15 missile, similar to the American AGM-69 SRAM. It was nicknamed Troika ('Trio' or third) in Russian service. 268 were built until 1993. As built, the Tu-22M included the provision for a retractable probe in the upper part of the nose for aerial refueling. The probe was reportedly removed as a result of the SALT negotiations, because with refueling it was considered an intercontinental range strategic bomber. The probe can be reinstated if needed. Tu-22M3s used to attack targets in Syria underwent modernization, during which the SVP-24-22 specialized computing subsystems were installed on them, significantly increasing the accuracy of the bombing. Tu-22M4 The development of the "Izdeliye 4510" began in 1983. Modernization with the installation of new engines NK-32 (from Tu-160) and with a change in engine air intakes. Modernization of avionics by installing a new PNK, radar "Overview" (from Tu-160), EW complex. Expansion of the range of weapons: 3 Kh-32 or 10 Kh-15 (with placement on 6 internal and 4 external points of suspension) or UPAB-1500 with a television guidance system. In 1990, a prototype was built at the Kazan aircraft factory. Works in this direction were discontinued in November 1991. The prototype aircraft No. 4504 is in the museum exposition of the AB Dyagilevo. Tu-22MR Several Tu-22M3s, perhaps 12, were converted to Tu-22M3(R) or Tu-22MR standard with Shompol side looking airborne radar and other ELINT equipment. Tu-22DP