While Russia's military elite have already seen the prototype - or perhaps prototypes - of the air force's nextgeneration heavy fighter, the aircraft will likely only make its public debut after first flight, if tradition is followed.

Senior Russian government and military leaders continue to insist first flight will be this year. Up to three prototypes are thought to be in various stages of final assembly at the Sukhoi manufacturing site in Komsomolsk-on-Amur.

The Russian air force's fighter fleet replacement strategy in the near to medium term is built around two Sukhoi programs: the Su-27SM2 (Su-35) development of the Flanker and the T-50 design to meet its fifth-generation fighter project, known as PAK FA.

MiG, having lost out to Sukhoi to develop a replacement to the former's canceled fifth-generation effort, known as MFI, has been working on a medium fighter concept, the lightweight multirole frontal aircraft (LMFS).

MiG officials have argued that while the PAK FA would replace the Su-27 Flanker, the air force will not be in a position to procure it in sufficient numbers to replace the MiG-29 Fulcrum as well. The LMFS was intended as a successor, with potentially broader export appeal than the PAK FA.

The Russian government gave Mikhail Pogosyan, long associated with Sukhoi, the challenging task of trying to sort out an ailing MiG at the end of last year.

One outcome of this move, however, is that LMFS appears to have been put on the back burner. Insiders at MiG say the LMFS project has not been included in the list of company priorities approved by Pogosyan, who also remains the general director of Sukhoi. In the nearer term, MiG has also been pressing the air force to order the MiG-35, though the status of such a purchase remains uncertain.

Russian Prime Minister Vladimir Putin was shown the T-50 in May during a visit to the Komsomolsk site. He took the opportunity of the trip to confirm that the air force will procure the upgraded Flanker. Company officials suggest 48 of the Su-27SM2 will be delivered through 2015.

The Su-27SM2, known for export as the Su-35, is viewed by many in the West as the near-term high-end platform against which their own capabilities are to be measured.

U.S. Air Force Lt. Gen. Daniel J. Darnell, deputy chief of staff for air, space and information operations, suggests that the Su-35 is "equal or superior" to the F-15. Meanwhile, the RAND Corp. characterizes the latest generation of the Su-27 as "not your father's Flanker."