Russia’s Su-57 Stealth Fighter Completes Engine Upgrade


Top image credit: Sukhoi


Program Technically on Track, But Will Logistics and Finances Ground New Russian Superfighter?


Russia’s contribution to the 5th Generation of air combat super-fighters moved ahead tangibly in early December with the successful flight of the first Sukhoi Su-57 using its new, upgraded Izdeliye-30 turbofan engine.

The first successful test flight with an Su-57 using the new Izdeliye-30 took place on Tuesday, Dec. 5, 2017. The 17-minute test flight by Sukhoi chief test pilot Sergei Bogdan was launched from the M.M. Gromov flight test center, in Zhukovsky, Russia about 25 miles outside of Moscow.

The new engine replaces the former NPO Saturn Izdeliye 117, also referred to as the AL-41F1. These original Izdeliye 117s were reported to be underpowered for the Su-57s 55,116 pound reported take-off weight. The Izdeliye 117 was never meant as a permanent powerplant for the Su-57 and its use drew criticism, some of it unwarranted, from western analysts.
The developmental engines on the PAK-FA were a consistent source of criticism, especially following a sensational compressor stall incident at the MAKS 2011 airshow. (Photo: Rulexip via Wikipedia)


The new Izdeliye 30 engines increase the Su-57 thrust to 11,000 kg without afterburner and 19,000 kg in afterburner according to reports. The engines also have fewer components and resulting lower maintenance costs and reduced maintenance schedule. The engine is claimed to have better fuel economy. As with most modern Russian fighters, the Izdeliye 30 is a thrust-vectored engine and has supercruise capability, enabling the Su-57 to fly at supersonic speeds without afterburner achieving longer range and better fuel economy at high speeds. Claims for higher efficiency published by subject matter expert Piotr Bukowski suggest the new engines are “17 to 18 percent more efficient than the [older] 117 engines.” As Bukowski pointed out in his recently updated reference book on Russian aircraft, “Russia’s Warplanes, Volume 1”, there was no definition offered for the what the specifics of “more efficient” meant in terms of performance.


One area many analysts have missed in terms of advantages for the Su-57 is cost. The price tag of an Su-57 is quoted as approximately $54M USD. If accurate, those costs are roughly one-third to one half the cost of the two operational U.S. fifth generation fighters, the F-22 Raptor and the F-35 Lightning II. Perhaps even more significantly, the Su-57 is also half the cost of China’s unusual looking J-20 Mighty Dragon 5th gen. fighter. China is also testing the J-31 Gyrfalcon, a 5th generation aircraft more intended for export than the Chinese point-defense J-20. Oddly, there do not appear to be any accurate published estimates of cost for the J-31, likely due in part to the degree of Chinese state subsidy of the program for any prospective buyers, a number influenced heavily by diplomatic and commercial relationships with China.
The first flight of the re-engined Su-57 in low overcast from December 5. (Photo: UAC Russia)


There has been a consistent populist trend of “bashing” or somehow diminishing the capability and progress of the Su-57/PAK FA program in western media. Most western criticism of the Su-57 program has been centered on the logistics of the program and its lack of commercial export success. While those factors are real, they miss the key insight that the Su-57 could emerge as a highly capable Gen 5 fighter platform at a third the cost of its contemporaries. This lower-cost business model for Su-57 could facilitate the historical Russian penchant for subverting quality to quantity on the battlefield. Not to suggest that the Su-57 is somehow inferior to other 5th gen aircraft, it may not be, but if the financial capability to field twice as many Su-57s as F-35s exists, this numerical superiority represents an interesting strategic argument for the new Russian combat aircraft.
Source: theaviationist.com