Background In 1969, the leaders of the Soviet Union decided to build an air superiority fighter aircraft that would be a match for the U.S. and other NATO fighters of the time, the PFI (perspektivnyi frontovoy istrebitel, advanced frontal fighter) program. It was supposed to have a greater range and weaponry than its Western counterparts.
Eight years later the designers at Sukhoi started to test a prototype named T10 (Flanker-A), making the first test flight on May 20, 1977. However, due to several technical flaws the aircraft did not meet the expectations of the Soviet airforce[?](VVS). After the second of the two prototypes crashed in July 1978, killing a pilot the development work was greatly slowed.
It was not until 1981 that the SDB built a new prototype, the T10S (Flanker-B), which was a radical redesign of the T-10. The new design showed sufficient improvements that it was accepted and became the Su-27, entering service in 1984. However, it was not until 1990 that certain problems were fully resolved. Despite that from 1986 a special Su-27 designated P-42 started to set the first in a series of performance records for rate of climb and altitude, the aircraft setting 27 new class records between 1986 and 1988.
It is a large and heavy aircraft, made of lightweight aluminium alloy and flown with a complex fly-by-wire control system, making it very manoeuvrable. In airshows the aircraft demonstrated its manoeuvrability with a Cobra or dynamic deceleration - briefly sustained level flight at a 120 degree up angle of attack. Certain Su-27s were also tested with thrust vector control, allowing the craft to perform hard turns with almost no radius, incorporate vertical somersaults into level motion and limited nose-up hovering.
A naval variant, the Su-33, first tested in August 1987 was planned for the Admiral Kuznetsov. The Su-33 is the only aircraft to have enough thrust to start from a carrier without the use of a catapult.
Around 680 were manufactured by the USSR, and 400 are in service with the Russian Tactical Air Force. Of the CIS member states, Kazakhstan has around 30 and is due a further 12 under agreement; Belarus has, possibly, 20; the Ukraine has around 60; Uzbekistan perhaps 25. China received 26 in 1991-92 and a further 24 in 1995-96 before signing a agreement for licensed manufacture of 200 as the J-11 in 1998. Vietnam has twelve and has order a further 24. Ethiopia has 8 Su-27A and 2 Su-27U.
Source for technical and weaponry data: Modern Combat Aircraft: Reference guide pp. 50-51 Minsk, "Elida", 1997, ISBN 985-6163-10-2 (Russian language).