Deliveries of fifth-generation fighters to Russia's Air Force will start in 2015 rather than in 2013 as previously announced, the Air Force chief said on Tuesday.

"In 2013, I hope... the [Sukhoi] PAK FA prototype will be ready and fine-tuned, and we will start deliveries to military units in 2015," said Col. Gen. Alexander Zelin.

A prototype of the fighter made its maiden flight in Russia's Far East on January 29. Prime Minister Vladimir Putin said after the 47-minute flight that the first batch of fifth-generation fighters would go into service in 2013.

Russia has been developing its newest fighter since the 1990s. The current prototype, known as the T-50, was designed by the Sukhoi design bureau and built at a plant in Komsomolsk-on-Amur.

Russian officials have already hailed the fighter as "a unique warplane" that combines the capabilities of an air superiority fighter and attack aircraft.

VLADIMIR, February 9 (RIA Novosti)