Question: Which plane is better?
The Sukhoi Su-35S Flanker-E, an advanced derivative of the original Soviet-era Su-27, is the most capable fighter Moscow has ever fielded. While the Su-35 is primarily designed to be an air superiority fighter, it also has a potent air to ground strike ability.
The Su-35S program has its origins in the Soviet Air Force’s program to develop a modernized Flanker derivative that was to be called the Su-27M. However, with the 1991 collapse of the Soviet Union and the subsequent economic meltdown and chaos in a newly independent Russia, funding for the Su-27M was halted. However, Sukhoi continued development of the Flanker aircraft in the hopes of securing export orders. The design bureau eventually concluded in December 2003 that it needed to completely revamp the Su-27 airframe to make the jet more competitive on the international fighter market. The first prototype of the new jet—called the T-10BM—made its first flight on February 18, 2008.
The operational version of the T-10BM was initially designated as the Su-35BM for the export market. The jet was later adopted by the Russian Air Force as the Su-35S an interim solution until the Su-57 PAK-FA was ready. The Russian government only decided to adopt the Su-35 after the 2008 Russia-Georgian war, where it became apparent that Moscow urgently needed to reform and modernize the rapidly decaying fragments of the Soviet military that remained under its control. As such, the Kremlin placed an order for 48 of the new Su-35S fighters in 2009 and the jet would feature prominently in the 2011 State Armament Plan.
Compared to the original Flanker, the Su-35S is equipped with a new lightweight airframe, enhanced engines with three-dimensional thrust vectoring, powerful new avionics and datalinks. Essentially, while the Su-35 externally resembles the Su-27, it is in basically a completely new aircraft—somewhat analogous to how the original McDonnell Douglas F/A-18A Hornet compares to the modern Boeing F/A-18E/F Block II or Block III. Indeed, the Su-35 has proven to be so capable, there are many in Russia’s military circles who wonder if the follow-on Su-57 is worth the time and money.