Saturn izdeliye 30 engines. Flight testing is planned to begin in 2022, and serial production is planned for the mid-2020s. FGFA Sukhoi/HAL FGFA was a planned version of Su-57 for Indian Air Force but India withdrew from the FGFA programme in 2018 before any prototype was built. The FGFA was intended to be the primary export version of the PAK FA and was to differ in 43 ways with improvements to stealth, supercruise, sensors, networking, and combat avionics. There were conflicting reports on the FGFA, with India detailing numerous improvements over the baseline PAK FA, while Mikhail Pogosyan, the head of United Aircraft Corporation, said in 2013 that the PAK FA and the FGFA will use "identical onboard systems and avionics". India has refrained from signing a deal with Russia citing concerns of aircraft's stealth, radar and supercruise capability in 2014 and ultimately withdrew from the programme in 2018. Other versions In 2008, UAC president Alexei Fedorov has said that any decision on applying fifth-generation technologies to produce a smaller fighter (comparable to the F-35) must wait until after the development of the PAK FA is completed. A naval version of the Su-57 was proposed for the Project 23000E or Shtorm supercarrier. Models of the aircraft carrier project are showing Su-57 on board, with folding wings and stabilators. The Su-57 should be able to use the takeoff ramp as well as the Electromagnetic Aircraft Launch System. The draft of the future state armament program (GVP) for 2024–2033 includes the development of a new carrier-based fighter based on the Su-57, albeit with deep modifications. The aircraft is used as a testbed for integration with UAVs as well as various subsystems (including weapon, control and navigation systems) being developed for Russia's future sixth-generation combat system, both in manned and unmanned version. In January 2019, it was reported the third flyable Su-57 prototype (bort. no 053) is being used for interaction with the Sukhoi S-70 Okhotnik UCAV, and testing of its avionics systems. In July 2021, it was officially announced that a two-seater variant of the Su-57 was under development, to be used for training pilots and for ensuring the control of the Sukhoi S-70 Okhotnik UCAV. This variant was also mentioned at the Army-2022 forum in August 2022. Operators Russian Aerospace Forces Russian Air Force – 76 in total on order. According to the manufacturer United Aircraft Corporation 10 were delivered as