June 1976 with V. A. Krechetov at the controls. Its export version with the R-29 engine and downgraded avionics (equivalent to those of the Su-17M2) was designated Su-22M (factory designation S-52K, NATO "Fitter-J") and first flew on 24 May 1977 with E. S. Soloviev at the controls. An export version with Su-17M3 avionics was designated Su-22M3 (factory S-52MK). The Su-17 was manufactured from 1976 to 1981, and the Su-22M from 1978 to 1984. The Su-17M3 and its export versions represented the most numerous variant, with almost 1,000 built. The Su-17M3 was planned at the same time as the UM trainer. The fuel capacity was increased by 260kg. Starting from the 38th batch the tailfin was raised with a radiotransparent guide and a fin was added on the underside of the tail to improve high-speed stability. A new KN-23-1 navigation system, the SAU-22M1 autopilot and the RV-15 (A-031) radio altimeter were added. Some aircraft later received an RSDN-10 Skip-2 (A-720) long-range radio navigation system, with its antenna installed on the leading edge of the tailfin. The SARPP-12GM flight recorder was replaced with the newer Tester-UZ recorder, and the SPO-10 radar warning receiver was replaced with the SPO-15A (izdeliye L006L) Beryoza. A Klyon-PS combined laser rangefinder/designator was installed, alongside the ASP-17BTs sight. The Su-17M3 could carry an SPS-141 (or the 142-143) Siren or an SPS-141MVG Gvozdika ECM pod. Infrared countermeasures could be deployed via KDS-23 launchers. The BSPPU fire-control system was also installed in the Su-17M3, which would control SPPU-22-01 gun pods suspended on the wings to automatically stay on target in automatic tracking mode, up to a depression angle of 30°. Two additional hardpoints were placed under the fuselage, with S-52-8812-300 pylons, on which BDZ-57MT or MTA racks would hold APU-68UMs, which in turn could carry Kh-23M or Kh-25 missiles. These hardpoints would also be capable of carrying the Kh-25ML or MR missiles, as well as the Kh-29L, mounted on an AKU-58 ejector rack. Some of the Su-17M3s were modified to the Su-17M3P standard, which would enable them to carry up to four Kh-27PS, two on the wings and two under the fuselage, or two Kh-58 anti-radiation missiles, which could only be carried on the fuselage pylons. A Vyuga-17 (L-086) target designator pod could be installed under the fuselage, with its receiver integrated into the aircraft's nose. The BDZ-57MT racks could also hold ordinary ordnance, such as the UB-16, -32 or