Sukhoi fifth-generation fighters facing engine problems

The Russian air force chief said that the fifth generation fighter planes that is being developed jointly by Sukhoi design bureau and Hindustan Aeronautic Ltd (HAL), India, is set to start flight trials in November. Col Gen Alexander Zelin said at the MAKS air show: "For the time being, the aircraft will use Saturn engines. There are problems, I admit, but research is continuing". The T-50 Advanced Frontline Aviation Complex (PAK-FA), going by the Russian designation of the 5th Gen fighter, is intended to replace the Russian air force's fourth-generation fighters, namely, the Su-27 Flanker and the MiG-29 Fulcrum. As the original Sukhoi design was not intended to incorporate a two-seater, the design bureau, along with HAL, is now working on strengthening the aircraft's structure so that it can carry increased weight. Earlier, in May, the Russian air force commander had indicated that three T-50 airframes had already been built, with at least one of these, very likely, a static fatigue test rig. Now, a Russian news agency quotes Gen Zelin as saying that the second prototype fighter jet was undergoing ''field trials.'' It is not clear what processes it is referring to when it says ''field trials,'' but very likely it is referring to land tests.