Market & Product

The path to certification

Work continues on the components Avio Aero is in charge of for the new GE9X, with tests leading to certification.
“We invent the future of flight, lift people up and bring them home safely”: this is GE Aviation’s mission statement, and it clearly inspires Avio Aero as well. The GE9X program, the new large engine in full growth phase that we have come to know increasingly well, especially in the past few months, is undergoing the stage of technological maturity, looking ahead toward the future and fulfilling the purpose inspired by this mission statement as much as possible.
April saw the FETT (First Engine to Test), where the largest engine in the world of airliners was switched on for the first time at the GE Aviation test center in Peebles, Ohio. Compared with other programs, the GE9X tackled the FETT ahead of schedule, gaining advantages in knowledge and technological upgrades on the engine itself in the lead up to certification.
Avio Aero has undertaken extensive efforts during the past few years so far to deliver the parts it is in charge of (the low-pressure turbine module and the accessory drive train, plus many other related components) in time for the FETT, and is now running a series of tests and overhauls in preparation for the SETT (Second Engine to Test), scheduled for January 2017. With the SETT, we will officially begin the challenging certification process of the Federal Aviation Administration, the US authority in charge.
The Avio Aero engineers working on the GE9X will spend this hot summer completing the Detailed Design Review of this product, including the project finalization, together with the release of the technical designs in certification configuration, and culminating with the Tollgate 7 (the name of the development stages), designed to consolidate the same configuration, at the component level as well as the engine program level.
Instead, in the fall, we will have to make additional progress in the “technological maturity” of the TiAl blades, manufactured at the Cameri plant and that, progressively, will be processed and finished in Pomigliano. In particular, we will have to complete the first kit for the certification engines, and a series of tests that will help improve confidence in the technology measured by the Technical Readiness Level (TRL).
At the same time, in Warsaw, at the new Cold Flow Test Facility (PoloniaAero), tests will begin on the new low-pressure turbine module, in order to optimize the technological and aerodynamic solutions of our module.
In June, at the Avio Aero Sangone Test Centers, tests will begin on the large accessory drive train, designed and manufactured by Avio Aero. These tests have required a significant modernization of the facilities, test benches and respective sensors (which ultimately measure performance and phenomena during testing), which came to 1.5 million Euros invested in our Turin test center.
The GE9X accessory box, therefore, will first go through a series of “classic” tests, i.e. all those that assess overall behavior, such as endurance testing, component efficiency testing, as well dynamic testing of the gears and the box that contains them, in terms of rotation speed and operating conditions, simulating the flight operating conditions and relative wear during the product’s life.
“For these tests, we will use water brakes instead of ‘real’ accessories, as they offer high extracted power density, are therefore more compact, and only require a water system and a few valves to operate. Whereas real accessories of various types (such as hydraulic oil pumps, fuel pumps, electric generators and others aboard the aircraft, powered by the motion transmitted by the AGB) have greater complications at the level of systems and safety,” explained Rosanna Viano, Principal Engineer-Chief Engineering at Sangone.
After these, beginning in September, we will run tests to investigate the torsional dynamics of the transmission (Torsional Dynamic Test), during so-called impulsive events, such as ignition stages, instant connection or disconnection of electrical loads on the accessory generator, breaking of the generator shaft. “For the first time here at Sangone, an ignition simulation will be carried out using a pneumatic starter (the compressed air starter motor that, thanks to a system of valves, can be powered with a mass flow rate of approximately 4 kg/s). Furthermore—in addition to the real accessory supplied to us by GE or Boeing—for these torsional tests, we will be able to capitalize on the lessons learned during the tests for the GEnx. Lastly, there will be a series of operations to evacuate such a mass of air and lower the noise generated,” concluded Rosanna.