The aircraft, which is the second Su-57 serially built, was delivered a year after the first built crashed during pre-delivery testing.
The Russian Aerospace Forces received on Dec. 25, 2020, their first serially built Su-57 “Felon” 5th generation fighter aircraft. According to a source in the military-industrial complex quoted by the TASS Russian News Agency, the aircraft entered service with one of the aviation regiments of the Southern Military District and four more Su-57s will be delivered in 2021.
Later, TASS quoted another source in the military-industrial complex (or perhaps the same) saying that the aircraft will be used to test hypersonic air-launched weapons at the 929th V.P. Chkalov State Flight Test Center in Akhtubinsk. RIA Novosti, another Russian News Agency, reported instead that the aircraft will be tested at Akhtubinsk before being moved to an operational unit.
While this kind of testing to be performed can’t be confirmed officially, spotters were able to confirm the Felon’s final base, as the aircraft was photographed during a stopover at Novosibirsk Tolmachevo airport with the logo of the Chkalov State Flight Test Center on the fuselage.
And here is its: the first production-model (i.e. non-prototype) Su-57 fighter was delivered to the Russian Air Force today (blue bort # 01). Photos from Светлана Баланва at the Tolmachevo Airport. https://t.co/jfORd9omdG pic.twitter.com/FL29BMWxJB
— Rob Lee (@RALee85) December 25, 2020
Another interesting detail is the aircraft’s bort number. This Su-57 is actually the second to leave the serial production line (T-50S-2 serial number 51002) but, since the first one crashed one year ago during pre-delivery flight testing, it received the bort number “01” instead of the expected “02”. The aircraft was previously photographed at the Komsomolsk-on-Amur Aircraft Plant before the beginning of the pre-delivery testing in October, but it was missing the Flight Test Center’s logo, showing only the bort number.
As we already reported, the crash of the Felon T-50S-1, which is actually the first since the first flight in 2010, was caused by a failure of the tail control system. After the crash, Sukhoi reportedly underwent some changes in the management of the company and, after the investigation, a number of technical improvements were applied to T-50S-2 and the other aircraft on the production line, delaying the first delivery by a year. Among the improvements, it was mentioned that the aircraft saw the hydraulic actuators of the flight controls replaced by electromechanical actuators. The company may also have to replace the crashed Su-57 at its own expense.
The Ministry of Defense of the Russian Federation and PJSC Sukhoi Company signed a contract for the first two serial Su-57s, T-50S-1 and T-50S-2, in August 2018, followed a year later by a contract for 74 other aircraft, which brought the total order to 76 Su-57s. The head of Rostec (State Corporation for Assistance to Development, Production and Export of Advanced Technology Industrial Product), Sergei Chemezov, already announced that the first delivery would happen by the end of 2020, followed later by the Russian Defense Minister Sergei Shoigu which added that 22 Su-57s will be delivered by the end of 2024, while the deliveries (provided that no further aircraft will be added to the order) will be completed by 2028 at a rate of 16 aircraft per year.
First production-version #Su57 delivered to the #VKS. Video filmed at Novosibirsk Tolmachevo Airport (see thread for images of the jet).
This is actually the second production version aircraft (first one crashed last year). https://t.co/qAAKKmxOHr
— Guy Plopsky (@GuyPlopsky) December 26, 2020
A new engine was specifically developed for the Su-57, known as Izdeliye 30 (literally Product 30), but, since the engine is not yet ready for production and tested only on an earlier prototype, T-50S-2 is still using the Saturn AL-41F-1, derived from the Su-35 Flanker E’s engine. The Product 30, which should provide 18,000 kgf of thrust instead of the 15,000 kgf of the current engine, is supposed to be more efficient than previous designs and able to give the Felon a top speed in excess of Mach 2 and a supercruise capability at Mach 1.3, featuring also 3D thrust vectoring and a “stealthier” nozzle. Production of the Product 30 engine should begin in 2022, with the first serial deliveries of the Product 30-equipped Su-57 in 2023
Speaking about the engine, the Felon was recently showcased in a video for the 100th anniversary of the Chkalov State Flight Test Center, where the radar blockers in the engines’ air intakes were allegedly exposed for the first time. The Su-57 uses a S-duct air inlet which does not cover the entire engine faces, as done for the F-22 Raptor and the F-35 Lightning II, leaving it exposed to radar signal reflection. The problem was said to be mitigated by a radar blocker that, however, was never clearly seen on any of the 11 prototypes or the first two serial aircraft.
As you may know, Su-57 is the official designation of the T-50 stealth multirole 5th generation fighter jet that was developed under the PAK-FA program. The requirements envisioned an aircraft capable of supersonic cruise flight with a long combat radius, low radar cross section, super-maneuverability and STOL (Short Take Off and Landing) characteristics, while retaining a substantial ground attack capability. The Su-57 features a substantially reduced Radar Cross Section compared to 4th generation Russian jets, principally in the frontal sector. It seems to be a compromise between reducing the RCS and obtaining high maneuverability and performance while maintaining large weapons bays to accommodate heavy payloads.
The airframe is said to use composite materials up to the 25% of the total weight and Radar Absorbing Materials (RAM). Some of these composite materials had to be sourced from abroad, but now they have been reportedly replaced by “Made in Russia” materials. Another technology that was showcased on the production line is the use of Augmented Reality during a number of processes in the assembly of the Su-57, with some examples showing its usage on the fuselage and the landing gear.
The Sukhoi Su-57 was often criticized by experts for many features that could degrade the low observability such as rivets, weapon doors’, engine nacelles’ and air inlets’ rounded shaping, rough panel’s seamlines, etc. Some of those problems seem to be mitigated in later prototypes and more could have been solved before the serial production. Many of these seem to be missing, or at least reduced, on the aircraft that are now being built serially, as it was visible on T-50S-2 while it was under construction this summer during a visit of the Russian Defense Minister.
Until now, as we already mentioned, 76 aircraft were ordered. RIA Novosti, however, reported that Deputy Minister Alexei Krivoruchko said in an interview that the Defense Ministry plans to expand the order for the Su-57 within the new state armament program for 2024-2033 that is currently being developed.
An interesting fact mentioned by the Izvestia newspaper is that the Su-57 may receive “invisibility covers” made of special polymers that are meant to protect the aircraft and its electronics from bad weather when parked in the open outside of hangars, while also making it difficult for foreign intelligence gathering systems to see the outlines of the aircraft in satellite imagery or to detect data about the aircraft’s electronic through SIGINT (SIGnals INTelligence).