MAKS 2009: Russia's 5th-Gen fighter jet engine facing problems

Zhukovsky, Moscow Region: Russia's fifth-generation fighter planes, being developed by the Sukhoi design bureau in collaboration with India's Hindustan Aeronautic Ltd (HAL), is set to start flight trials in November, the Russian air force chief said Thursday. He also revealed that the fighters' engine development programme had run into some problems.

Speaking at the MAKS air show outside Moscow, Col Gen Alexander Zelin said: "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.

The PAK-FA will also be inducted into the Indian Air Force as a two-seater version, compared to the Russian air force's single-seat version, and it is the Russian version that is due to commence trials later in the year.

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, the Itar-Tass 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.