|AL-31 / 41F|
|Saturn AL-31 FN turbofan engine|
|Manufacturer||NPO Saturn, UMPO, NPC Saljut|
|Major applications||Sukhoi Su-27|
Sukhoi S-70B Okhotnik-B (UCAV)
|Developed from||Lyulka/Saturn AL-21F-3A|
|Developed into||Saturn AL-41|
The Saturn AL-31 is a family of military turbofan engines, developed by the Lyulka, now NPO Saturn, in the Soviet Union/Russia, originally for the Sukhoi Su-27 air superiority fighter. It produces a thrust of 28,000 lbf (123 kN) with afterburning in the AL-31F, 31,000 lbf (137 kN) in the AL-31FM (AL-35F) and 33,000 lbf (145 kN) in the AL-37FU variants. Currently it powers all Su-27 derivatives and the Chengdu J-10 multirole jet fighter which has been developed under a Russian license by China. The AL-31 is a Heavily Upgraded Version of the Lyulka AL-21
|AL-31F||The basic engine developed to power the Su-27 fighter||Salyut, UMPO||1981||27,600 lbf (122.6 kN)||No||Sukhoi Su-27, Shenyang J-11, Sukhoi Su-30MKK, Sukhoi Su-30 (Salyut)||In service/production|
|AL-31F3||Improved variant for the naval version Su-33||Saturn Lyul'ka||28,200 lbf (125.57 kN)||No||Sukhoi Su-33||In service/production|
|AL-31FP||Improved variant for the Indian Su-30MKI with thrust vectoring||Salyut, HAL||2000||27,600 lbf (122.6 kN)||Yes||Sukhoi Su-30 MKI, Sukhoi Su-30MKM||In service/production|
|AL-31FN||Improved variant for the Chengdu J-10||Salyut||2002||28,000 lbf (124.5 kN)||No||Chengdu J-10||In service/production|
|AL-31FN Series 3||Improved variant for the Chengdu J-10B||Salyut||2013||30,200 lbf (134.3 kN)||No||Chengdu J-10||In service/production|
|AL-31F M1||Improved version for the Russian Air Force||Salyut||2007||30,300 lbf (135 kN)||Yes||Sukhoi Su-27SM, Sukhoi Su-30, Sukhoi Su-34||In service/production|
|AL-31F M2||Improved version for the Su-34 and Chengdu J-20||Salyut||2012||32,600 lbf (145 kN)||No||Sukhoi Su-34, Chengdu J-20||In service/production|
|AL-37FU||Advanced derivative for the Su-37||UMPO||32,600 lbf (145 kN)||Yes||Sukhoi Su-37||Experimental derivative for the Su-37|
|AL-41F-1S (117S)||Advanced derivative for the Su-35||UMPO||2010||31,900 lbf (142 kN)||Yes||Sukhoi Su-35||In service/production|
|AL-41F1 (117)||Advanced derivative for the Sukhoi Su-57||UMPO||2010||33,000 lbf (147 kN)||Yes||Sukhoi Su-57 prototype||In service/production|
The AL-31FP and AL-37FU variants have thrust vectoring. The former is used in the Su-30MKI export version of the Su-30 for India & Sukhoi Su-30MKM for Malaysia . The AL-31FP can deflect its nozzle to a maximum of ±15° at a rate of 30°/sec. The vectoring nozzle is used primarily in the pitch plane. The AL-31FP is built in India by HAL at the Koraput facility under a deep technology transfer agreement.
It can tolerate severely distorted air flow from the intake. In the twin-engine Su-27, left and right engines are interchangeable. The Mean Time Between Overhaul (MTBO) for the AL-31F is 1000 hours with a full-life of 3000 hours.
Salyut supplies AL-31 variants to fighters operated by the People's Republic of China. The J-10 uses the AL-31FN while the J-20 uses the AL-31FM2 as an interim engine until the domestic WS-15 is ready.
According to Saturn's Victor Mihailovich Chepkin, chief designer of the 117 and 117S engines, the Chinese WS-10 was developed with the aid of the AL-31's maintenance technical documentation., this was recently confirmed by AVIC 
Intended to power the Su-35BM, the izdeliye 117S, or AL-41F1S, is derived from the AL-41F1 of the Su-57, with the key difference being the separate engine control system of the AL-41F1S. The engine produces 86.3 kN (19,400 lbf) of thrust dry, 137.3 kN (30,900 lbf) in afterburner, and 142.2 kN (32,000 lbf) in an emergency. The AL-41F1S fan diameter of 932 mm (36.7 in) is 3% greater than the AL-31's 905 mm (35.6 in). This engine has an assigned life of 4,000 hours and an MTBO of 1,000 hours. The first flight of this engine was completed in an Su-35BM on 20 February 2008. On 9 August 2010, Ufa-based company UMPO started supplying 117S engines (AL-41F1S) intended for Su-35S fighters.
Intended to power the fifth-generation Sukhoi Su-57 fighter, the izdeliye 117, or AL-41F1, is a highly improved AL-31F derivative, with some application of technology from the Saturn AL-41F. Its development began in 2004 and has increased fan diameter, new high- and low-pressure turbines, provisions for thrust-vectoring nozzles similar to the AL-31FP, and a digital control system (FADEC) integrated into the aircraft's flight controls. According to Sukhoi director Mikhail Pogosyan, the AL-41F1 is a new fifth-generation engine built specifically for the Su-57. Though the specifics remain classified, the engine's thrust was increased by 24.5 kN (5,500 lbf) over the AL-31 while the engine weight growth was reduced by 150 kg (330 lb). The AL-41F1 produces 147 kN (33,000 lbf) of thrust in afterburner and has a dry weight of approximately 1,600 kg (3,500 lb) and thrust-to-weight ratio of 9.3:1. Like the AL-31F, the AL-41F1 has 4 low-pressure compressor (fan) and 9 high-pressure compressor stages. Mikhail Pogosyan further mentioned that the AL-41F1 meets the Russian Air Force requirements and will be installed in production Su-57 fighter which will be supplied to the Russian Air Force and prospective foreign clients.
The AL-41F1 (117S) is an interim engine meant for prototype and initial production batches of the Su-57. The definitive second stage for the aircraft is designated izdeliye 30 and will eventually replace the AL-41F1 after the mid-2020. The izdeliye 30 engine will have increased thrust and fuel efficiency as well as improved reliability and lower costs. Bench testing of the new engine will start in 2014 according to the general designer-director of the NPO Saturn Eugeny Marchuk. Test flights began in 2017 being still underway in 2020. At the time it was expected that serial deliveries of Su-57 fifth-generation fighters fitted out with the new engines could begin in 2022.
Data from Rosobornexport
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