Front Horizontal Tail unit (FHT) was installed for the first time on the one of the first serial SU-27 (T-10-24). The tests of this plane began in May, 1985, In order to do it, a rind part of a wing center section was modified. In September they started tests on studying of FHT influence on dynamics of take-off from springboard T-2 on the Ground Test-training Air Complex (GTAC). According to this program only six flights were carried out (on January, 20, 1987 the plane was lost in failure.
Results of tests showed, that setting of FHT allows to increase carried properties of the plane and receive the circuit «integral unstable triplane". At the same time in the Department of Design-technology Bureau (OKB) works on the further development of the machine, first of all in a direction of increase of its opportunities on defeating of the targets on a surface of the ground and water, including with using of the high-precision controlled weapon were being carried out. Development of the new plane was headed by N.F.Nikitin (since 1996 -V.Konokhov).
New complex Board Radio Electronic Equipment (BREE) with new Radar Station (RS) of big power was installed on the board of the plane. It resulted in using of strengthened support of the chassis, including a two-wheeled forward one, which was the same as in SU-24 Besides the increase in weight of the plane, the nomenclature of arms and volume of the equipment required to strengthen a wing, to equip it with additional points of a suspension bracket and to install Front Horizontal Tail Unit (FHTU). For arrangement of a new BREE, an strengthened forward support, FHTU and a system of refueling during a flight a new head part of a fuselage with increased radio transparent fairing of the antenna RS and lateral hatches of access to the equipment (it is similar to T-10-1) were developed. New "head" of the plane, for the preservation of stability and controllability in the traveling channel, caused an increase of vertical tail unit and the area of control surface of a direction. For installation of a part of the new equipment the length and the diameter of tail fairing were increased, and the container of a braking parachute was transferred on the top surface of the Tail Part of the Fuselage (TPF) before a fuel tank. The angle of an inclination of the back of the pilot's armchair for the providing of the best acceptability of overloads was increased up to 30 °.
The plane is equipped with a new control system of the arms, including COMPUTER control of the weapon for attacks of the ground targets, a multipurpose RS and an optoelectronic system. Multimode jamproof RS has a mode of mapping of a ground surface and attack of the ground targets. It allows to find out the air targets on a range of up to 400 kms, and ground targets on a distance of up to 200 kms, simultaneously to accompany not less than 15 air targets and to attack not less than six targets simultaneously by missiles. SU-35 is capable to strike distant high- precision and powerful impacts on rears of the opponent, to strike the surface ships at a great distance, to fight with planes DRLO and REB, and also with VKP. The ground or sea targets can be attacked without call in the zone of opponent's Air Defense.
On June, 28, 1988 a pilot - verifier O.G.Tsoy began flight tests of the first experimental copy T-10-1. Serial production of SU-27M was started in Komsomolsk-on-Amur. On April, 1, 1992 the first serial plane left KnAAPO, and the first foreign display of the plane to potential customers and general public took place in the autumn of 1992 on an air show in Farnborough. On the eve it was given the name SU-35. Year later, in August, 1993 the plane was shown at the international aerospace exhibition 1993 in Zhukovsky. In 1995 T-10-1 was given to the museum of the Air Forces in Monino (near Moscow).
Code designation of the NATO - Flanker-E (Marginal).
