In numbers Through the lens Video
At the same time existed also a other publication of engine with nozzles of directed w'sis of (level configuration) type AL-31F, in a experimental plane Su -27UB. The trials finally were limited in the 20 test flights without the program has been completed.
Su-27UB LL-UV (PS): First flight of prototype was realised on 31 December 1989 (1990).
The interruption of program was owed firstly in the lack of chalk-lines and second in technical reasons and in the problems that resulted in the manufacture of levels of nozzles.
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Su-27UB LL-UV (PS) Experimental plane.
At the trials the transformation of flow of fuel behind the turbine with level nozzles decreased considerably the w'si (In percentage 14-17%). The manufacture is heavier with the nozzles of variable address. In the nozzles of variable address we have elasticity (expanding stress) and moreover in the level nozzles we have also transverse stress.
These lead to the increase of resistance in order to we avoid the deformity of nozzles. Thus we add moreover weight in the manufacture.
The problem it could untie itself in the manufacture of engine and use materially as "carbon - carbon ". This materials have smaller weight in the manufacture and bigger resistance in big temperatures. A such manufacture needs effective heat insulation of (special coverings from high - temperature ceramic).
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Su-27UB LL-UV (PS) Experimental plane.
lla materially that could be used in the manufacture for increase of "beneficial life of" engine they are found in the initial stages of trials and this it was the reason in order to is preferred engine AL-41F provided with nozzles of variable address (proportional manufacture is also used in the engine of type AL -31FP for the ships Su-37 and Su-30MK).