An investigation into the vertical axis control power requirements for landing VTOL type aircraft onboard nonaviation ships in various sea states

The problem of determining the vertical axis control requirements for landing a VTOL aircraft on a moving ship deck in various sea states is examined. Both a fixed-base piloted simulation and a nonpiloted simulation were used to determine the landing performance as influenced by thrust-to-weight ratio, vertical damping, and engine lags. The piloted simulation was run using a fixed-based simulator at Ames Research center. Simplified versions of an existing AV-8A Harrier model and an existing head-up display format were used. The ship model used was that of a DD963 class destroyer. Simplified linear models of the pilot, aircraft, ship motion, and ship air-wake turbulence were developed for the nonpiloted simulation. A unique aspect of the nonpiloted simulation was the development of a model of the piloting strategy used for shipboard landing. This model was refined during the piloted simulation until it provided a reasonably good representation of observed pilot behavior

Flight test results for a separate surface stability augmented Beech model 99

A flight evaluation of a Beech model 99 equipped with an attitude command control system incorporating separate surface stability augmentation (SSSA) was conducted to determine whether an attitude command control system could be implemented using separate surface controls, and to determine whether the handling and ride qualities of the aircraft were improved by the SSSA attitude command system. The results of the program revealed that SSSA is a viable approach to implementing attitude command and also that SSSA has the capability of performing less demanding augmentation tasks such as yaw damping, wing leveling, and pitch damping. The program also revealed that attitude command did improve the pilot rating and ride qualities of the airplane while flying an IFR mission in turbulence. Some disadvantages of the system included the necessity of holding aileron force in a banked turn and excessive stiffness in the pitch axis

Quality Management in Broiler and Pork Supply Chains Aimed at Reducing Risks of Antimicrobial Resistance: an Elicitation Workshop

Development of antimicrobial resistance (AMR) is considered to be one of the main human health problems. Livestock production, particularly hog and broiler production, are regarded as sources of human exposure to resistant pathogens. It is envisaged that the issue of AMR will be on the agenda of both policy makers at various levels (e.g. supra-national (EU), national and production organisations) and researchers. In the last decade a large range of (potential) exposure and/or risk reducing measures have become available or are envisaged. Examples are:− On-farm: reduction of usage of antimicrobial agents, more robust animals, therapeutic alternatives to antimicrobials and increased bio-security;− Beyond-farm: various cleansing and disinfection measures, cross-contamination reducing logistics within the entire chain, various types of meat processing ways which reduce the prevalence of pathogens and further contamination.Chain-wide implementation of (sets of these) measures is complex and involves simultaneous consideration of various issues, such as: the potential to reduce microbial exposure to humans, the (economic) impact on livestock production, (cost-)effectivity technology and acceptance by the general public, asymmetry of effects and costs between chain participants, the risk of counteracting risk-reduction downstream the chain, legal and institutional thresholds, compliance and governance. Quantitative risk-based economic analysis of (sets of) measures throughout the supply chain can support decision making in this regard. Such analysis should be comprehensive and focused on optimal (i.e. low risks and low additional costs) and coherent sets of measures.Given the complexity of the matters, a conceptual framework was developed to facilitate subsequent quantitative analysis. This framework describes qualitatively all possible factors and aspects that influence both human exposure to pathogens and economic performance. Two levels are considered: (1) the on-farm level and (2) the beyond-farm level up to consumer. Moreover, the issue of (economics of) (non-) compliance is included. Furthermore, the framework includes a rather complete list of risk reducing measures and their direct and indirect relations with human exposure and production costs.Because (1) the range of potential measures, and (2) the range of various criteria each (set of) measures can be characterized by and on which they can have positive or negative impacts on, analysing all options together is quite laborious. Therefore, it makes sense to elicit a set of promising measures for subsequent quantitative analysis

Flight test evaluation of a separate surface attitude command control system on a Beech 99 airplane

A joint NASA/university/industry program was conducted to flight evaluate a potentially low cost separate surface implementation of attitude command in a Beech 99 airplane. Saturation of the separate surfaces was the primary cause of many problems during development. Six experienced professional pilots who made simulated instrument flight evaluations experienced improvements in airplane handling qualities in the presence of turbulence and a reduction in pilot workload. For ride quality, quantitative data show that the attitude command control system results in all cases of airplane motion being removed from the uncomfortable ride region

Design, analysis and control of large transports so that control of engine thrust can be used as a back-up of the primary flight controls

A propulsion controlled aircraft (PCA) system has been developed at NASA Dryden Flight Research Center at Edwards Air Force Base, California, to provide safe, emergency landing capability should the primary flight control system of the aircraft fail. As a result of the successful PCA work being done at NASA Dryden, this project investigated the possibility of incorporating the PCA system as a backup flight control system in the design of a large, ultra-high capacity megatransport in such a way that flight path control using only the engines is not only possible, but meets MIL-Spec Level 1 or Level 2 handling quality requirements. An 800 passenger megatransport aircraft was designed and programmed into the NASA Dryden simulator. Many different analysis methods were used to evaluate the flying qualities of the megatransport while using engine thrust for flight path control, including: (1) Bode and root locus plot analysis to evaluate the frequency and damping ratio response of the megatransport; (2) analysis of actual simulator strip chart recordings to evaluate the time history response of the megatransport; and (3) analysis of Cooper-Harper pilot ratings by two NaSA test pilots

A Conceptual Aerospace Vehicle Structural System Modeling, Analysis and Design Process

A process for aerospace structural concept analysis and design is presented, with examples of a blended-wing-body fuselage, a multi-bubble fuselage concept, a notional crew exploration vehicle, and a high altitude long endurance aircraft. Aerospace vehicle structures must withstand all anticipated mission loads, yet must be designed to have optimal structural weight with the required safety margins. For a viable systems study of advanced concepts, these conflicting requirements must be imposed and analyzed early in the conceptual design cycle, preferably with a high degree of fidelity. In this design process, integrated multidisciplinary analysis tools are used in a collaborative engineering environment. First, parametric solid and surface models including the internal structural layout are developed for detailed finite element analyses. Multiple design scenarios are generated for analyzing several structural configurations and material alternatives. The structural stress, deflection, strain, and margins of safety distributions are visualized and the design is improved. Over several design cycles, the refined vehicle parts and assembly models are generated. The accumulated design data is used for the structural mass comparison and concept ranking. The present application focus on the blended-wing-body vehicle structure and advanced composite material are also discussed

Life-Cycle Cost Estimation for High-Speed Vehicles: from the engineers’ to the airline’s perspective

This paper aims at upgrading the holistic Cost Estimation methodology for High-Speed Vehicles already developed by Politecnico di Torino and the European Space Agency (ESA) to encompass different stakeholders’ perspectives. In details, the presented methodology combines International Air Transport Association (IATA) best practices with a detailed Life- Cycle Cost (LCC) assessment, which includes the evaluation of Research, Development, Test and Evaluation (RDTE) Costs, Production costs and of Direct and Indirect Operating Costs (DOC and IOC). The integrated approach allows to further extend the capabilities of the inhouse developed HyCost tool to support all the actors of the product value-chain (including engineers, manufacturers, airlines and customers) in assessing the economic sustainability of a newly under-development high-speed vehicle. However, considering the need of providing all these cost analyses perspectives since the early design stages, the derived Cost Estimation Relationships are mainly derived on statistical bases. To cope with the uncertainties that affect the initial statistical population and consequently, the CERs, this paper presents each cost item together with the estimation of related prediction intervals. Finally, results of the application of the upgraded cost estimation methodology and of the upgraded tool to the LAPCAT MR2.4 high-speed civil transport are reported and discussed

Study on a camber adaptive winglet

Morphing structures are devices intended to be implemented in specific parts of the aircraft such to improve some aspects of the flight such as performance and maneuverability. More specifically for the wings, the in flight capability of adaptation of airfoil profile and control surfaces bring possibility to the aircraft operate at optimum performance condition during all flight phases. Morphing structures can only lead to optimal flight maneuverability and performance conditions if the morphed geometry leads to an improved flight condition. Aiming at the reduction of the lift induced drag in all flight phases, this research focus on the application of the genetic optimization algorithm for the definition of the camber section of an winglet. This research proposes the optimization at four different flight phases namely: climb, heavy cruise, mid cruise and light cruise. BLWF – a full potential equation solver coupled with 3D boundary layer modelling – is adopted in the aerodynamic performance, e.g. lift and drag ratio, calculation. A conventional genetic algorithm is adopted in the optimization of the camber of the airfoil composing the winglet. This paper describes the optimization procedure and compares geometries showing that the in flight change of the winglet geometry can sensibly contribute to the improvement of the aircraft performance reducing the fuel consumption