NPO” Saturn completed the endurance tests for Experimental engine 117S Engine on 30th January, 2008. As per NPO “Saturn” project engineer Yevgeny Marchukova, “from engines point of view, there are no obstacles whatever for the beginning of the flight tests of the first Su-35. All obligations before the customer are executed “.
For guaranteeing the service life of 100 hours, the engine bench tests was composed of 200 hours (with the fulfillment of 100 cycles of tests, 6000 cycles of the turning of rotary nozzle), including 16 hours of hot tests with the imitation of high-speed regimes.
The 117S engine is a major upgrade of the AL-31F and has a thrust of 14.5 tonnes, which exceeds the figures of the basic engine by 2 tonnes. It mounts the fan with a 3 % larger diameter (932 mm over 905 mm), advanced high- and low-pressure turbines and all-new digital control system. A provision has been made for using the thrust vector control nozzle similar to that of the AL-31FP. The upgrade has resulted in thrust hiking by 16 % to 14,500 kgf (kN) in afterburner mode and totaling 8,800 kg in the maximal non-after burning mode. Compared to the current AL-31F, the new engine’s service life will increase by 2–2.7 times, with the time between overhauls increasing from 500 hours to 1,000 hours, time before first overhaul standing at 1,500 hours and assigned life spiking from 1,500 hours to 4,000 hours.
There are five engines in the testing batch. 117S-01 is for special tests in assuring first flight; 117S-02 is for gas dynamic stability and extended tests for assuring first flight; 117S-03 was sent to the flight laboratory where strain gauge measurements of the low pressure chamber under takeoff conditions were recorded; 117S-04 and 117S-05 have been delivered to KnAAPO for the Su-35 flight.
Currently, “NPO” Saturn” and ” UMPO ” (Ufa Engine Production Association) have started to manufacture the final eight engine’s, which will be used to refine the product. Of those, two will be the engine test resource, one – will be for thermobaric chamber in CIAM, the three engine will be delivered at the second aircraft Su-35, one for special tests and one for official tests.
Tests of the first engine of final layout it is planned during February 2008 and delivery of the engines for the second airplane are planned for March – April 2008.