The A400M, a military transport aircraft for tactical, logistic and humanitarian missions, is one of the most ambitious projects in recent aviation history. It is equipped with four TP400-D6 turboprop engines built by Europrop International (EPI), the consortium made up of MTU, Rolls-Royce and Snecma. Construction of the Power GearBox or PGB used on these aircraft, the largest ever built in the western world, has been assigned to Avio Aero.
This highly complex component is crucial for the performance of the engine, to which it transfers power for the propellers. Our customer EPI has always recognized the high level of technology and performance of our PGB and is fully aware of the complexity and utter novelty of the engine. It is precisely for this reason that during its development over the past 4 or 5 years, a series of technical improvements have been made to the engine’s materials and configurations (in terms of the details of the transmission rather than the design geometry) and consequently to our product.
In particular, after producing around 40 PGBs a configuration improvement was introduced that posed an exciting challenge for Avio Aero: construction of a dedicated and certified Repair Station at Pomigliano to overhaul the first PGBs already in operation and upgrade them to the latest configuration.
This challenge was taken up with great determination by numerous areas of our company: Commercial Operations, Product Support and Product Management, Finance, Engineering, Sourcing, as well as Maintenance, Quality and Technology (for our Supply Chain).
Even more importantly, our customers were astonished by the timeframes we managed to meet. Compared to an initial work plan of 18 months, subsequently shortened to 12, we succeeded in building and certifying the repair station at our Pomigliano facility for the start-up of CRO (component repair and overhaul) activities on the PGB for the TP400-D6 in under 12 months.
In a new area set up for CRO in the Service area in Pomigliano, the overhaul operations will be performed using 353 different tools and items of equipment that have been specially designed for disassembling, lifting, cleaning, moving, repairing and reassembling the PGBs. After being designed by our Engineering department, the technical drawings for these tools were carried out by our Polish colleagues and passed on to the suppliers who built them in record times with the support of the engineering team in Pomigliano and the Sourcing team in Rivalta.
As for the details of the structures, it was necessary to build a testbed (for flushing) which was certified in June thanks to the support provided by the Technologies team to the Sangone experimental laboratories. Instead of the usual 12 months, this testbed took just 6 months to build on the basis of a testbed model already present in Turin.
And thanks to the work of the Maintenance department, a second testbed used for calibrating the PGB Input Shaft was equipped with a special heat-controlled chamber that monitors temperature and humidity in the test chamber. This was likewise built in just six months thanks to consulting provided by the Sangone team and Prof. Barbato from Turin Polytechnic, and was described by the technicians as a test bed with greater measuring capacity and complexity.
Last but not least, the manual that operators and technicians will use when overhauling the PGBs was written jointly by the Engineering teams in Brindisi and Pomigliano and by Product Support. It consists of 4,000 pages of instructions, cycles and procedures loaded onto the repair station’s IT system. In the meantime operators and technicians have completed in-depth training courses in Pomigliano and Rivalta to enable them to understand the operations needed to meet Quality and Airworthiness requirements and thereby attain final certification based on ENAC audits, demonstrating that we are now capable of operating on flight components for the TP400-D6.
This is an excellent example of the kind of pro-activity and teamwork that is needed when dealing with complex products and processes requiring commitment and dedication to meet objectives. We have asked our many colleagues and their teams who have worked with such dedication to offer us their personal comments on achieving this goal