Location: São José dos Campos, São Paulo
Segment: Military
Problem: Develop an inerting system specifically for wing tanks that could achieve FAA certification
Solution: By integrating the venting and fuel systems, Eaton designed a complete interaction to deliver a single solution for wing-tank inerting.
Results: Enhanced safety for the KC-390 while reducing overall aircraft weight and increasing reliability
Background:
In 2011 Eaton was selected by Embraer S.A. to supply fuel system components for the next generation of KC-390 military transport aircraft. In early 2012, Embraer announced that Eaton also would supply the aircraft’s on board inert gas generating system, or OBIGGS.
Eaton will design, develop and supply airframe fuel system components for the KC-390, which is currently in development, and also provide production units and aftermarket support throughout the life of the program.
Eaton’s experience on many of the world’s most advanced civilian and military aircraft platforms will be instrumental in helping Embraer achieve the latest regulatory certification requirements for the KC-390, including FAA inerting system certification. In 2011, Eaton successfully completed the industry’s first multi-tank inerting gas distribution system certification process for the Boeing 787. Eaton’s in-depth knowledge of aircraft fuel and vent systems is an essential background for fuel tank inerting systems, where interactions between inert gas deposit locations and the fuel tank vent system are critical for safe aircraft operation.
Challenge:
Eaton’s legacy in both fuel and pneumatic systems reaches back more than 60 years. What sets Eaton apart in the industry is how it has combined capabilities to develop both the nitrogen generation and inertgas distribution sub-systems for OBIGGS.
As the fuel-inerting certification requirement transitioned from military to civilian aircraft, so did technical challenges associated with developing fuel-inerting systems for different fuel tank designs. Initial civil fuel-inerting systems focused on only one part of the aircraft fuel tanks — the center fuel tank in the fuselage. The introduction of composite-winged civilian aircraft presented a new challenge to the industry to develop an inerting system specifically for wing tanks that could achieve FAA certification. Military platforms such as the KC-390 also include wing tanks in their fuel system design.
Solution:
The challenge for Eaton was proving that every single bay in the wings could be inerted. By integrating the venting and fuel systems, Eaton designed a complete interaction to deliver a single solution for wing-tank inerting.
Eaton uses computational fluid dynamics (CFD) to analyze fluid flow and model the operation of fuel pumps and valves. For recent aircraft certification programs, Eaton has expanded this capability to analyze the mixing of nitrogen-enriched air (NEA) inside aircraft fuel tanks. Initially, results were verified with a fifth-scale model of an aircraft fuel tank fitted with oxygen sensors. Eaton expanded this CFD capability and verification by using a B737 wing tank for a larger-scale test. The rig was again fitted with oxygen sensors to verify results of CFD analyses. Eventually, the FAA validated all of these models during the B787 certification process.
The experience from CFD analysis and testing has enabled Eaton to accurately characterize mixing characteristics of different compartments around the aircraft. Validating models are then integrated with the NEA generation system, distribution system, flammability model and vent system to provide a powerful tool for analyzing the complete inerting system, as well as the interaction of all of its sub-systems.
Result:
Eaton’s experience in certifying multi-tank inerting gas distribution systems will enhance safety for the KC-390 while reducing overall aircraft weight and boosting reliability. The certification process can take up to four years to complete, and the KC-390 currently is on schedule to achieve full certification in 2016.
The KC-390 contracts clearly signal that Eaton’s innovation in fuel and inerting systems and its focus on expanding into emerging markets are driving global business growth. Eaton will continue to develop fuel-inerting systems and related technologies for newgeneration military, commercial and business jet applications that optimize aircraft safety, reliability, weight savings and fuel efficiency.
