The Sukhoi T-50 PAK-FA smoking on the fuselage while in flight over Russian Air Force Base. The smoke came up caused by sonic boom or condensation in the air. Whilst, take a look its livery, Russian Air Force changed its grey livery to dominated blue sky there. The T-50 is the fifth generation jet fighter developed by Sukhoi as an order from Russia government. This jet fighter deliberately built to compete with F-22 Raptor of Lockheed Martin of United States. Else, China also built fifth generation jet fighter, called Chengdu J-20. Some aviation enthusiasts told that the T-50 has not proven yet in battle warfare.