European aero engine company Europrop International (EPI) has admitted that a major error on its part has played a very large role in delaying the Airbus A400M military transport aircraft programme.

EPI is responsible for the design, development, production, maintenance, support and sales of the TP400-D6 turboprop engine that powers the A400M. Each A400M will have four of these engines, which are the most powerful turboprops ever developed in the West.

EPI's error involves the certification of the full authority digital engine control (Fadec) software for the engines. The A400M was, and is, intended to be used for humanitarian missions as well as military ones. Consequently, the aircraft requires civil as well as military airworthiness certification.

While the responsibility for the certification of the airframe vests with Airbus, it is EPI that is responsible for getting the engines certified. And EPI failed to grasp that obtaining civil certification required that they be able to show traceability and accessibility in the writing of the Fadec software.

As a result, the company failed to establish the necessary evidence for the traceability and accessibility of this software. Europe's civil aviation certification agency, the European Airworthiness Safety Authority (EASA) thus refused certification of the Fadec software.

This meant that the first A400M, rolled out from the final assembly line in Seville, Spain, in June last year, and otherwise ready to fly by September, has not yet been permitted to make its first flight.

To meet EASA's regulations, EPI has had to rewrite all the Fadec software codes and create the mandatory traceable evidence showing the development of these software codes. To do this, EPI had to treble its work force.

Meanwhile, the TP400-D6 engine has completed some 2 600 hours of testing in a ground rig, and vibration, endurance and large bird ingestion tests have been completed.

The engine has also achieved 23 hours in flight, and 60 running hours, on the C-130 Hercules test-bed aircraft operated by Marshall Aerospace of the UK on behalf of EPI. As only one of the test-bed's four engines is a TP400-D6, it is able to fly despite the Fadec software certification issue.

EPI is a joint-venture company, with its head office in Munich, Germany, and a liaison office in Madrid, Spain. It is jointly owned by France's Snecma (itself part of the Safran Group), which has a 32,2% share, Britain's Rolls-Royce, with a 25% share, Germany's MTU (22,2%), and Spain's ITP (20,6%).

By Keith Campbell

Source: Engineering News