Su-47 (S-37) Berkut Experimental Fighter Aircraft, Russia
The Sukhoi Design Bureau of Moscow, Russia has developed the Su-47 (previously called the S-37 Berkut or Golden Eagle) fighter aircraft, which first flew in September 1997. Su-47 is in a forward swept wing configuration and uses a highly unstable triplane (with three main lifting surfaces) aerodynamic configuration. The Su-47 completed the first stage of flight trials in December 2001. In May 2002, Sukhoi was selected as prime contractor for the next-generation Russian PAK FA fighter programme. The PAK FA will be a development of the Su-47 but without the forward swept wings.

MANOEUVRABILITY

The Su-47 has extremely high agility at subsonic speeds enabling the aircraft to alter its angle of attack and its flight path very quickly, and it also retains manoeuvrability in supersonic flight.
Maximum turn rates and the upper and lower limits on air speed for weapon launch are important criteria in terms of combat superiority. The Su-47 aircraft has very high levels of manoeuvrability with maintained stability and controllability at all angles of attack.
Maximum turn rates are important in close combat and also at medium and long range, when the mission may involve engaging consecutive targets in different sectors of the airspace. A high turn rate of the Su-47 allows the pilot to turn the fighter aircraft quickly towards the next target to initiate the weapon launch.
The swept-forward wing, compared to a swept-back wing of the same area, provides a number of advantages: higher lift to drag ratio; higher capacity in dogfight manoeuvres; higher range at subsonic speed; improved stall resistance and anti-spin characteristics; improved stability at high angles of attack; a lower minimum flight speed; and a shorter take-off and landing distance.

FUSELAGE

The Su-47 fuselage is oval in cross section and the airframe is constructed mainly of aluminium and titanium alloys and 13 per cent by weight of composite materials.
The nose radome is slightly flattened at the fore section and has a horizontal edge to optimise the aircraft's anti-spin characteristics.


The Mikoyan Project 1.44/1.42 is a Russian Air Force prototype fifth-generation air-superiority fighter aircraft. Apart from a number of names along the lines of "Object/Project 1.44/1.42", the aircraft is also known as the MiG-MFI. It was unofficially known for a time as "MiG-35", although MiG is now using this designation for the export version of the MiG-29OVT. The MFI has also been referred to by some sources as MiG-39. Despite the prototype status of the 1.44/1.42, NATO has assigned the reporting name "Flatpack" to this aircraft. The relationship between the 1.44 and 1.42 designations is unclear outside the military world, and these are generally used interchangeably. For simplicity, the 1.44 designation is used throughout this article.

Development
The MiG 1.44/1.42 has been shrouded in mystery throughout the course of its existence. The Russian government cancelled the MFI program in 1997 due to the unacceptably high per-unit cost of the aircraft (Ф2.05 billion RUR, US$70 million). Development continued, with the first test flight taking place on February 29, 2000 and two confirmed test flights in 2001. In Russia's abandonment of the MFI program, the PAK FA (Перспективный Авиационный Комплекс Фронтовой Авиации - Perspektivnyi Aviatsionnyi Kompleks Frontovoi Aviatsyi - Prospective Air Complex for Tactical Air Forces) program was initiated for the development of an aircraft designed to fill a role similar to that of the F-22, and come at a size and cost similar to that of the F-35 Lightning II.

In 2001, India agreed with Russia to make the PAK FA program a development/production joint-venture between the two nations. Both Mikoyan-Gurevich and Sukhoi submitted concepts to the Defense Ministry for the PAK FA program (MiG entering an updated Project 1.44), but the Russian Defense Ministry selected the Sukhoi Design Bureau as the primary contractor for the PAK FA fighter. Design work has commenced on a backward-swept winged derivative of Sukhoi's experimental Su-47 Berkut aircraft. PAK FA proves to be a very ambitious program, with production of the PAK FA fighter planned to commence in 2010. MiG-MAPO and Yakovlev have also been mentioned as secondary contractors. The MiG 1.44 is currently serving as a technology demonstrator for the PAK FA program. The in-development PAK FA aircraft will use the same in-development Lyulka AL-41F engine planned for the 1.44.