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ECOA is an active software architecture research programme conducted by the French Republic and United Kingdom. It is one product of the recent Defence and Security Co-operation Treaty signed between the two nations. This paper provides an overview of the programme goals and progress as well as an introduction to the technology being developed and comparison to related initiatives. The goal of the ECOA programme is to define an open software architecture that enables collaborative development of mission system software. The ECOA programme is needed to reduce development and lifecycle costs of future military air programmes. For this reason the programme has a specific focus on combat-air mission systems but the underlying technology is general purpose, applying to multiple military and civil domains. At present, the programme has defined a concept, delivered a set of initial technical standards and produced a joint demonstrator to validate the technology developed.

This paper describes how Fluorescent Penetrant Inspection (FPI) was used in the past, how it is used now and how it will be used in the future. The United States Air Force (USAF) and Pratt & Whitney (P&W) now use a fully-automated FPI process with manual visual inspection. With direction and funding provided by the USAF/Aeronautical System Center (ASC), these fully-automated FPI processors, located at Kelly Air Force Base in San Antonio, Texas were developed, manufactured, installed, qualified and put into operation by Pratt & Whitney. This paper will cover the following: the Qualification and Acceptance Tests which include test objectives, test articles, test facility, test equipment, test results, and training.

This paper describes Pratt &Whitney's pioneering work in “constrained dynamic inversion,” a control algorithm architecture for multivariable systems that must operate tight to limits. A hallmark of gas turbine control is the prevalence and fundamental importance of tightly holding limits. When constrained dynamic inversion is applied to gas turbine systems control, this algorithm enables operation closer to physical and operational limits, while also providing faster and more precise responses. In addition to more fully exploiting systems physical capabilities, this architecture provides for the independent and finely coordinated control of system variables-of-interest even when each effector affects all variables. A distinctive feature of this algorithm is that it can be implemented on state of the art controllers at update rates consistent with vehicle control.

Pilots in fighter aircraft can be subjected to high temperatures during ground operating phases in hot climate conditions, especially if APU mode is not available. A Cooling Generation System (CGS) used with a protective thermal garment for fighter aircraft pilots has been developed that allows cooling of the pilot in the cockpit. The unit is designed to operate under worst case conditions and requires only that the pilot plugs in upon entering the cockpit. A liquid circulates inside the garment that covers the pilot’s torso, arms and head (area under the helmet). The temperatures are defined to guarantee the user’s comfort. The pilot can adjust the power delivered by the CGS, i.e. the temperature of the circulating fluid, up to a maximum cooling capacity of 400 W. The CGS design is based on a small variable speed compressor with a brushless motor, which is the outcome of a dedicated development, and a custom-made evaporator and condenser for maximum efficiency and minimum volume.

Over the past few decades, advanced methods have been developed for the analysis of digital systems using mathematical reasoning, i.e., formal logic. These methods are supported by sophisticated software tools that can be used to perform analysis far beyond what is practically achievable using “paper and pencil” analysis. In December 2011, RTCA published RTCA DO-178C [1] along with a set of technical supplements including RTCA DO-333 [2] which provides guidance on the use of formal methods towards the certification of airborne software. Such methods have the potential to reduce the cost of verification by using formal analysis instead of conventional test-based methods to produce a portion of the verification evidence required for certification.

Model Based Safety techniques have been developed for a number of years, though the models have not been customised to help address the safety considerations/ actions at each refinement level. The work performed in the MISSA Project looked at defining the content of “safety models” for each of the refinement levels. A modelling approach has been defined that provides support for the initial functional hazard analysis, then for the systems architectural definition level and finally for the systems implementation level. The Aircraft functional model is used to apportion qualitative and quantitative requirements, the systems architectural level is used to perform a preliminary systems safety analysis to demonstrate that a system architecture can satisfy qualitative and quantitative requirements.

This paper provides an insight into how the introduction and implementation of the blending borescope used to perform on-wing blending of compressor blades on Pratt & Whitney (P&W) Engines has resulted in significant savings. It describes the following: Commercial statistics and savings; Military statistics and potential savings; P&W maintenance team; What is on-wing blending; The capabilities of on-wing blending; The contents of a typical blending borescope inspection kit; Test results; Measurement of Foreign Objects Damage (FOD); Installation of the equipment; How to blend FOD; How to measure the repair and observe how the equipment provides precise results; How to polish the repair. Typical commercial cost savings for blending assembled compressors are in the order of $360,000.00 per event, compared with engine teardown cost.

In the frame of the development of the European EVA Suit, a complete trade-off was conducted to select the lower torso architecture. This study, performed under an ESA contract, included a formal trade-off dealing with all cost and programmatic impacts together with a technical assessment based on man rated underwater evaluations and analysis. The candidate architectures were: the European baseline including 2 hip and 2 thigh bearings, the Russian like soft ORLAN-DMA, a soft lower torso including 2 thigh bearings and another soft one including 2 calf bearings. The idea was to compare the different design performances without having necessarily developed the 4 pressurized lower torsos and then also to gain experience on predicting methods for such ergonomic/kinematic studies. The trade-off was based on the manned underwater evaluation of ergonomical suit simulators (wet suit concept), supported by the 1-g pressurized evaluation of the Russian ORLAN-DMA and CAD-CAM kinematic analysis.

The Flexible Assembly Cell for Aeronautical Industry (FACAI) is described. The cell was developed in order to take advantage of the benefit of hard automation while retaining the flexibility of the manual assembly system it replaces. A description of both the generic equipment, selected to be non-specific to both the process and the assemblies intended to be built, is provided. In addition, all specific hardware, including end-effectors and fastener distribution systems are described, along with the rationale for their choice. The reasons for the modular design are explained. The means by which the flexibility goal was achieved are outlined. The demonstrated ability of the cell to install a wide range of fasteners (solid rivets, lockbolts, Hilocks) without the need for manual reconfiguration is detailed. The means by which both the quality and safety goals were attained are explained.

This paper synthesizes the shoulder joint development activities performed in the frame of the European EVA Space Suit System (ESSS) programme. The shoulder joint belongs to the anthropomorphic enclosure encompassing the crewmember, protecting him against space environment while ensuring him adequate mobility, dexterity and visibility. A conceptual trade-off selected two candidates likely to fulfil the stringent shoulder joint requirements: an all-soft joint and a hybrid “rolling convolute”. Representative pressurized breadboards were designed, manufactured and tested. The tests addressed both intrinsic performance, via torque/flexion hysteresis curves and ergonomic characteristics via a “man in the loop” evaluation, involving a suit demonstrator. Tests results completed the trade-off, thus enabling the industrial team to formulate recommendations and propose further development studies.

The intent of a balanced engine design process is to satisfy all systems requirements including operability, performance and durability. Due to the complexity of the trade-off process of the various metrics it is possible that system improvements may be required after a turbofan engine enters production. Also, in the case of derivative engines, configured for increased performance, the flowpath aerodynamics may be challenged and may have to be examined to ensure there is no flow field anomaly. By incorporating special diagnostic aero instrumentation at the earliest opportunity any required operability improvement can be identified and corrective action taken. The paper first delineates the component matching challenges of twin spool mixed flow turbofan engines. Then it discusses investigation of various potential destabilizing influences.

This technical paper presents the author's recommended approach to one aspect of managing flight safety - conducting Safety Risk Analyses (SRA) on in-service problems that may threaten flight safety. The author did not develop this statistically based approach for assessing the risk of future events, but has helped to improve it and highly endorses it. In conducting a safety risk analysis, the analyst might decide to perform a “quick” SRA and will need a minimal amount of information that will show the relative level of flight safety risk. When the analyst decides a complete safety risk analysis is needed, the possible approaches and level of details included in the SRA can vary greatly from company to company.

A Distributed Engine Control Working Group (DECWG) consisting of the Department of Defense (DoD), the National Aeronautics and Space Administration (NASA)- Glenn Research Center (GRC) and industry has been formed to examine the current and future requirements of propulsion engine systems. The scope of this study will include an assessment of the paradigm shift from centralized engine control architecture to an architecture based on distributed control utilizing open system standards. Included will be a description of the work begun in the 1990's, which continues today, followed by the identification of the remaining technical challenges which present barriers to on-engine distributed control.

Bleeding in engines is essential to mitigate the unmatched air massflow between low and High Pressure (HP) compressors at low speed settings, thus avoiding unstable operation due to surge and phenomena. However, by emerging the More Electric Aircraft (MEA) the engine is equipped with electrical machines on both high and Low Pressure (LP) spools which enables transfer of power electrically from one spool to another and hence provides the opportunity to operate engine core components closer to their optimum design point at off-design conditions. At lower power setting of the engine, HPC speed can be increased by taking power from LP shaft and feeding it to HP shaft which can lead to the removal of the bleeding system which in turn reduces weight and fuel consumption and help to overcome engine instability issues. Fuel consumption can be decreased by decreasing inconsistent thrust with the aircraft mission for flight and ground idle settings.

Avcorp Industries Inc. recognized the need to reduce assembly labor costs in order to stay competitive with global competition. After two years of research and investigation it was determined that a joint project with Dassault Aviation provided the most viable solution. The key elements of the technology developed by Dassault were its high flexibility and rapid payback of capital investment. This paper describes the system and the application. The structure’s design and robotic system design were performed in parallel. A number of design challenges had to be overcome. Many of these issues encountered were common to any automated assembly application. By covering these challenges Avcorp was able to introduce automated assembly at a level that had typically been previously attained exclusively by much larger enterprises. The robotic system consists of two anthropomorphic robots, which work both individually and in tandem.

A lot of studies have been carried out over the last decades on SLD ice accretion challenges. Many of them referred to SLD physics modelling such as break-up, splashing, bouncing, etc… and relied on numerous physics experiments. Different models have been developed in Europe and North-America and have been implemented in several numerical tools, widely in 2D but more and more in 3D. As these tools are intended to be used increasingly among the community, deficiencies have to be deeper investigated. This paper provides some highlights on specific needs linked to SLD impingement and ice accretion, especially for 3D high fidelity computations. Regarding the results, deficiencies on the numerical side and on experimental needs will be highlighted in order to feed brainstorming for ongoing SLD projects such as in European Union H2020 ICE-GENESIS.

In the present study, an experimental investigation was conducted to characterize a hot-air-based anti-/de-icing system for the icing protection of aero-engine inlet guide vanes(IGVs). The experimental study was conducted in a unique icing research tunnel available at Iowa State University (i.e., ISU-IRT). A hollowed IGV model embedded with U-shaped hot-air flowing conduit was designed and manufactured for the experimental investigations. During the experiments, while a high-speed imaging system was used to record the dynamic ice accretion or anti-/de-icing process over the surface of the IGV model for the test cases without and with the hot-air supply system being turned on, the corresponding surface temperature distributions on the IGV model were measured quantitatively by using a row of embedded thermocouples.

A through-flow based Monte Carlo particle trajectory simulation is used to calculate the ice crystal paths in the low pressure compressor of a high bypass ratio turbofan engine. The simulation includes a statistical ice particle breakup model due to impact on the engine surfaces. Stage-by-stage ice water content, particle size and particle velocity distributions are generated at multiple flight conditions and engine power conditions. The majority of the ice particle breakup occurs in the fan and first LPC stage. The local ice water content (IWC) within LPC is much higher than the ambient conditions due to scoop effects, centrifuging and flow-path curvature. Also the ice particles approach the stators at lower incidence angles than the air flow. The simulation results prompt the need to revisit the approach for properly setting up boundary conditions for component or cascade testing.

Coating has been recently considered as having good potential for use in preventing in-cloud icing on the leading edge of the lifting surfaces of an aircraft in cold climates. In terms of wettability, a coat may exhibit hydrophobicity or hydrophilicity depending on its specific properties. The same applies to the ice adhesion strength, which may be either high or low. It is thus necessary to determine which type of anti-icing or de-icing coat would be appropriate for a particular application in order to fully utilize its specific properties. Notwithstanding, a coat is incapable of preventing ice accretion by itself, and a perfect icephobic coat is yet to be developed. Coating is also sometimes applied to the surfaces of electrical heaters and load-applying machines to enable them to function more effectively and use less energy. The coating used for an electric heater, for instance, should be hydrophobic because of the need for rapid removal of molten water from the surface.

Engine module performance trending and engine system anomaly detection and identification are core capabilities for any engine Condition Based Maintenance system. The genesis of on-condition monitoring can be traced back nearly 4 decades, and a methodology known as Gas Path Analysis (GPA) has played a pivotal role in its evolution. GPA is a general method that assesses and quantifies changes in the underlying performance of the major modules of the engine (compressors and turbines) which directly affect performance changes of interest such as fuel consumption, power availability, compressor surge margins, and the like. This approach has the added benefit in that it enables anomaly detection and identification of many engine system accessory faults (e.g., variable stator vanes, handling and customer bleeds, sensor biases and drift). Legacy GPA has been confined to off-board analysis of snapshot data averaged over a stable flight conditions when the engine is in steady state operation.