Airbus A320 Research Articles

Lessons Learned in Implementing a Practical Aircraft System Health Management (ASHM) Syste

Aircraft System Health Management (ASHM) is a web application used for Boeing 787® and Airbus A320® and A380® aircraft system monitoring by airlines and field engineers worldwide which also serves all existing Aircraft Condition Monitoring Function (ACMF) reports, Flight Deck Effects (FDE) records and aircraft metadata to UTC engineering teams to aid in efficient aftermarket support. This enables creation, testing and fielding of off-board diagnostics and prognostics modules of varying levels of sophistication, that convert this abundance of existing data into actionable and timely knowledge about a/c fleet health. ASHM encourages and promotes cross functional collaboration allowing those with the most subject matter expertise within the enterprise to access the field data they need to observe operational performance and to create, test and field modules that can actively diagnose and warn field service professionals of problems when and potentially before they arise. A practical case study related to monitoring of the novel Boeing 787® electromechanically driven distributed aircraft environmental systems is presented. This use case motivates a discussion of pragmatic lessons learned in the fielding of diagnostic and prognostics solutions.

Aspects of Damage Tolerance and Fatigue of CFRP Structural Components

Lightweight structures are one key issue for all future mobility concepts. Carbon fibre reinforced plastics (CFRP) play an important role in these disciplines due to their outstanding mechanical performance regarding to their weight. Therefore, CRFP structures have been widely used since decades in aerospace industry resulting in improvements in payload, fuel consumption and range. The Airbus A350, Boeing B787 in civil airplane industry as well as military products like the NH90 transport helicopter are examples of this development towards “all composite”-aircrafts with nearly all structural parts made out of composite materials. The increasing importance of electro mobility in the automotive sector leads to the necessity of new structural design approaches apart from commonly used metallic designs. The objectives are to reach adequate ranges by compensating for the additional weight due to electric components of hybrid or purely electric driven vehicles by improved lightweight structural design. The technological peak of this development are the i-models of BMW using CFRP for body-in-white-structure for the first time in commercial automobiles. A main difference of CFRP-structures towards metallic ones is the behavior regarding damage tolerance and fatigue. For helicopter composite structures this issue is newly defined in §573 of the relevant certification specifications (CS for EU, FAR for US) valid since December 2012. This paper for the first time summarizes the necessary efforts and possible methods to show compliance for this specific topic in the aerospace industry. As there is no similar specification or rule available now, this may serve as an example in other fields like the automotive industry. This paper discusses approaches used in aerospace industry to design robust and lightweight CFRP structural components, which can also be transferred to automobile structures. This includes definitions and standard practices defining the damage, generation of design allowables and necessary testing effort.

European parabolic flight campaigns with Airbus ZERO-G: Looking back at the A300 and looking forward to the A310

Aircraft parabolic flights repetitively provide up to 23s of reduced gravity during ballistic flight manoeuvres. Parabolic flights are used to conduct short microgravity investigations in Physical and Life Sciences and in Technology, to test instrumentation prior to space flights and to train astronauts before a space mission. The use of parabolic flights is complementary to other microgravity carriers (drop towers, sounding rockets), and preparatory to manned space missions on board the International Space Station and other manned spacecraft, such as Shenzhou and the Chinese Space Station CSS.The European Space Agency (ESA), the ‘Centre National d’Etudes Spatiales’ (CNES, French Space Agency) and the ‘Deutsches Zentrum für Luft- und Raumfahrt e.V.’ (DLR, the German Aerospace Centre) have used the Airbus A300 ZERO-G for research experiments in microgravity, and at Moon and Mars gravity levels, from 1997 until October 2014. The French company Novespace, a subsidiary of CNES, based in Bordeaux, France, is in charge of the organisation of Airbus A300 ZERO-G flights. A total of 104 parabolic flight campaigns have been organised by ESA, CNES and DLR since 1997, including 38 ESA, 34 CNES and 23 DLR microgravity campaigns, two Joint European ESA-CNES-DLR Partial-g Parabolic Flight Campaigns, and seven ESA Student campaigns.After 17years of good and loyal services, this European workhorse for microgravity research in parabolic flights has been retired. The successor aircraft, the Airbus A310 ZERO-G, is being prepared for a first ESA-CNES-DLR cooperative campaign in Spring 2015.This paper looks back over 17years of microgravity research in parabolic flights with the A300 ZERO-G, and introduces the new A310 ZERO-G that will be used from 2015 onwards.

An Overview of High-Performance Aircraft Structural Al Alloy-AA7085

AA7085 Al alloy is a new-generation, high-strength, quench-insensitive alloy that features in airframe applications such as massive bulkhead and wing spars structures in Airbus A380 and Joint Strike Fighter aircrafts. This alloy has a great potential in replacing currently used high-strength AA7xxx alloys in many international and national military aircraft programs [Hawk, Su-30, MiG series, light combat aircraft (Tejas), Hindustan turbo/jet trainer, light combat helicopter, advanced light helicopter, and fifth-generation fighter aircrafts]. An effort has been made to highlight the processing, heat treatment, properties and applications of the AA7085 Al alloy from the existing literature on the AA7085 alloy. The potential applications of this alloy are presented and compared with the currently used AA7075 Al alloy. A typical process cycle involved in the manufacturing of wrought AA7085 alloy products is described in detail. Particularly, the precipitation mechanisms involved in the different temper conditions are critically reviewed with the supporting microstructures. The mechanical properties with a particular emphasis on tensile, fatigue, and fracture toughness properties are discussed in detail based on the analysis of experimental data. The effects of temper conditions on the stress corrosion cracking and exfoliation corrosion have also been reviewed critically.

Laser cutting of carbon fiber reinforced plastic using a 30 kW fiber laser

Today, industrial usage of carbon fiber reinforced plastic (CFRP) is steadily increasing, with an amount of 67 000 ton/yr [“Carbon fibers and carbon fiber reinforced plastics (CFRP)—A global market overview,” Report, Research and Markets Ltd., Dublin, Ireland, 2013]. Products such as the Boeing 787 and Airbus A350 in the aerospace sector, as well as the BMW i3 from the automotive industry consist of more than 50% of CFRP in their structural weight. At the same time, these products also have comparatively high production volumes, e.g., >10 000 cars/yr in the case of the BMW i3 [“BMW undertakes global launch of i3 EV,” see http://www.ihs.com/products/global-insight/industry-economic-report.aspx?id=1065981621, May 20, 2014]. Therefore, a higher degree in automation and cost-efficiency is needed in production. Due to the highly abrasive carbon fibers, conventional machining processes result in short tool life and high costs. Therefore, laser cutting of CFRP as a wear-free alternative has lately become the focus of several research groups. Two different approaches are commonly chosen: cutting by short- and ultra-short pulsed laser systems to reach a process regime of cold ablation and cutting with continuous wave (cw) lasers at high cutting speeds. For the latter approach, it has already been shown that by increasing power and cutting speed, the heat affected zone (HAZ) can be reduced due to less time allowed for heat conduction [Bluemel et al., “Laser machining of CFRP using a high power laser—Investigation on the heat affected zone,” in Proceedings of 15th European Conference on Composite Materials, Venice, Italy (2012)]. Graf and Weber introduced a perpendicular heat flow model, calculating that the required intensity to cut 2 mm of CFRP with a HAZ of 10 μm using a cw laser is 109 W/cm2. The required cutting speed is 8.3 m/s [T. Graf and R. Weber, “Laser applications from production to machining of composite materials,” in Proceedings of EALA, Bad Nauheim, Germany (2012), pp. 289–299]. In this paper, experiments using an ultra-high power fiber laser system of 30 kW to cut CFRP laminates are presented. Although it is not possible to fully achieve the intensities proposed by Graf and Weber, the intensities of approx. 108 W/cm2 of the setup still allow for a practical validation of the CFRP cutting at very high laser power. Due to the high intensities, high cutting speeds per laser pass are necessary. A special experimental setup is chosen with a rotational movement of the specimen, reaching a feed rate of 85 m/s. The heat affected zone was considerably reduced to 78 μm with the 30 kW system, 10% lower than with a 5 kW system under comparable conditions. Although today no scanner systems are available that could handle these high intensities at such high cutting speeds, the experiments still show that processing of CFRP with cw laser systems at highest power has a potential in order to reduce the heat damage to the material.

Health Monitoring for the Flight Control EMAs

In the frame of the more electrical aircraft context initiated by Airbus A380, A400M and A350 programs, the Electro-Mechanical Actuators (EMA) are good candidates for electrical flight control actuation. In this scope, this paper presents the current status and the perspectives of the Health Monitoring (HM) function developed for the flight control system EMA technologies. It highlights the main technical challenges to face: jamming susceptibility, “on board” maintenance reduction, operational reliability and safety margin increase. Thanks to dedicated R&T activities about the EMA Health Monitoring, the current results are very promising at this stage and have enabled demonstration of TRL4 at the Aircraft system level according to the maturity readiness level process. In the coming years, the activities will be conducted up to flight test campaign demonstration.

THE PROJECT OF ADAPTATION OF AIRPORT TO EXECUTING THE IRREGULAR SERVICE OF AIRPLANE AIRBUS 380

The aircraft Airbus A380 is the biggest aircraft in present time. Many airports need to adapt their airside infrastructure. The main duties concerns upgrading runways, and taxiways, relocating taxiways and even relocating aircraft stands and buildings to provide sufficient wings clearance. There are many hubs in the world, which must rebuild elements of infrastructures for A380. Besides these large hub and main base airports, there are other airports around the world that will experience A380 operations. The operating frequency could be either on regular basis, such as one or two scheduled arrivals a day, but also may be a much lower frequency such as for a flight diversion. Such diversions could be either due to the unavailability of the destination airport (because of weather or operational issues) or because of an in-flight emergency. It is in the interest of in-flight safety to have a reasonable number of alternate airports and runways available in addition to the scheduled ones. Aircraft operations regulations make a distinction between destination alternate aerodromes, other alternate aerodromes required to be adequate (e.g. in JAR-OPS 1) and in-flight diversion aerodromes. For those alternate airports, large-scale changes to their existing airside infrastructure would be financially excessive and never be economical. On the other hand, especially in the case of a filed alternate, a minimum should be done to properly handle the aircraft and its passengers. In paper is presented necessary requirements to service of airplane the Airbus A380. It is presented on examples of Chopin’s airport in Warsaw. Service of this type of airplane requires adaptation of parameters of runway, taxiway and ground operations.

The IAGOS-core greenhouse gas package: a measurement system for continuous airborne observations of CO2, CH4, H2O and CO

Within the framework of IAGOS-ERI (In-service Aircraft for a Global Observing System – European Research Infrastructure), a cavity ring-down spectroscopy (CRDS)-based measurement system for the autonomous measurement of the greenhouse gases (GHGs) CO2 and CH4, as well as CO and water vapour was designed, tested and qualified for deployment on commercial airliners. The design meets requirements regarding physical dimensions (size, weight), performance (long-term stability, low maintenance, robustness, full automation) and safety issues (fire-prevention regulations). The system uses components of a commercially available CRDS instrument (G2401-m, Picarro Inc.) mounted into a frame suitable for integration in the avionics bay of the Airbus A330 and A340 series. To enable robust and automated operation of the IAGOS-core GHG package over 6-month deployment periods, numerous technical issues had to be addressed. An inlet system was designed to eliminate sampling of larger aerosols, ice particles and water droplets, and to provide additional positive ram-pressure to ensure operation throughout an aircraft altitude operating range up to 12.5 km without an upstream sampling pump. Furthermore, no sample drying is required as the simultaneously measured water vapour mole fraction is used to correct for dilution and spectroscopic effects. This also enables measurements of water vapour throughout the atmosphere. To allow for trace gas measurements to be fully traceable to World Meteorological Organization scales, a two-standard calibration system has been designed and tested, which periodically provides calibration gas to the instrument during flight and on ground for each 6-month deployment period. The first of the IAGOS-core GHG packages is scheduled for integration in 2015. The aim is to have five systems operational within 4 yr, providing regular, long-term GHG observations covering major parts of the globe. This paper presents results from recent test flights and laboratory tests that document the performance for CO2, CH4, CO and water vapour measurements.

Method for Lightweight Optimization for Aerospace Milled Parts – Case Study for a Helicopter Pilot Lightweight Crashworthy Seat Side Struts

Abstract As a follow up of the light weight design policies, topology optimization of aerospace milled parts is on the focus of development teams from many years. In the last period (especially after Airbus A380 roll up) there were presented methods to save weight and even parts on airplanes manufactured this way. Emerged form an aerospace structures design team, paper presents a method to combine the 2D topological optimization with classic 3D static stress design iterations, leading to significant weight savings. The results will be implemented on a future helicopter operator seat under development for a multirole helicopter.

FlightGear as a Tool for Real Time Fault-injection, Detection and Self-repair

The development of fault-detection and self-healing methods at both a hardware and software level in modern aircraft is an attractive prospect. However it is expensive to design and test these techniques using real aircraft. This paper appraises the viability of using FlightGear, an open- source Flight Simulator, as a test-bed for these approaches. The paper characterises the realism of various aspects of a model of the Airbus A380. Interfaces are established to abstract critical control system routines from FlightGear. These functions are replicated in both software and hardware environments. The control data can then be subjected to fault-injection and the control modules modified to enable fault-detection and self-healing. By applying cluster analysis techniques to training sets of data, a fault-detection, diagnosis and self-healing model is designed to address these injected faults. FlightGear is found to provide highly realistic simulation of aircraft systems and instrumentation. Hardware-in-the-loop testing shows promise as an area for future work. The proposed fault-detection model is found to provide 96% accuracy.

Signal and model-based fault detection for aircraft systems

The paper presents several examples on model and signal based fault detection in aircraft Electrical Flight Control System (EFCS). The examples are taken from past and on-going research projects and actions between Airbus Group and the University of Bordeaux (France). The techniques presented have been tested on highly representative aircraft benchmarks, real flight data, or through realtime implementation on Airbus test facilities and real A380 flight tests. The focus is on specific problems associated with each design when it comes to providing viable technological solutions and mechanization schemes. One of the proposed model-based solutions has received certification on new generation Airbus A350 aircraft. It is a great achievement for SAFEPROCESS academic community as it demonstrates that a model-based fault detection technique is now flying (first commercial flight: January 15, 2015).

A correlation linking the predicted mean vote and the mean thermal vote based on an investigation on the human thermal comfort in short-haul domestic flights

The results of an experimental investigation on the human thermal comfort inside the cabin of some Airbus A319 aircrafts during 14 short-haul domestic flights, linking various Italian cities, are presented and used to define a correlation among the predicted mean vote (PMV), a procedure which is commonly used to assess the thermal comfort in inhabited environments, and the equivalent temperature and mean thermal vote (MTV), which are the parameters suggested by the European Standard EN ISO 14505-2 for the evaluation of the thermal environment in vehicles.The measurements of the radiant temperature, air temperature and relative humidity during flights were performed. The air temperature varied between 22.2 °C and 26.0 °C; the relative humidity ranged from 8.7% to 59.2%. The calculated values of the PMV varied from −0.16 to 0.90 and were confirmed by the answers of the passengers. The equivalent temperature was evaluated using the equations of Fanger or on the basis of the values of the skin temperature measured on some volunteers.The correlation linking the thermal sensation scales and zones used by the PMV and the MTV resulted quite accurate because the minimum value of the absolute difference between such environmental indexes equalled 0.0073 and the maximum difference did not exceed the value of 0.0589. Even though the equivalent temperature and the MTV were specifically proposed to evaluate the thermal sensation in vehicles, their use may be effectively extended to the assessment of the thermal comfort in airplanes or other occupied places.

Fuel and time savings by flying continuous cruise climbs: Estimating the benefit pools for maximum range operations

This paper estimates the benefits, in terms of fuel and time, which continuous climb operations can save during the cruise phase of the flights, assuming maximum range operations. Based on previous works, a multiphase optimal control problem is solved by means of numerical optimization and using accurate aircraft performance data from the manufacturer. Optimal conventional trajectories (subject to current air traffic management practices and constraints) are computed and compared with ideal continuous operations only subject to aircraft performance constraints. Trip fuel and time for both concepts of operations are quantified for two aircraft types (a narrow-body and a wide-body airplane) and a representative set of different trip distances and landing masses. Results show that the continuous cruise phase can lead to fuel savings ranging from 0.5% to 2% for the Airbus A320, while for an Airbus A340 the dispersion is lower and savings lie in between 1% and 2%. Interestingly, trip time is also reduced between 1% and 5%.

Aircraft‐type dependency of contrail evolution

AbstractThe impact of aircraft type on contrail evolution is assessed using a large eddy simulation model with Lagrangian ice microphysics. Six different aircraft ranging from the small regional airliner Bombardier CRJ to the largest aircraft Airbus A380 are taken into account. Differences in wake vortex properties and fuel flow lead to considerable variations in the early contrail geometric depth and ice crystal number. Larger aircraft produce contrails with more ice crystals (assuming that the number of initially generated ice crystals per kilogram fuel is constant). These initial differences are reduced in the first minutes, as the ice crystal loss during the vortex phase is stronger for larger aircraft. In supersaturated air, contrails of large aircraft are much deeper after 5 min than those of small aircraft. A parameterization for the final vertical displacement of the wake vortex system is provided, depending only on the initial vortex circulation and stratification. Cloud resolving simulations are used to examine whether the aircraft‐induced initial differences have a long‐lasting mark. These simulations suggest that the synoptic scenario controls the contrail cirrus evolution qualitatively. However, quantitative differences between the contrail cirrus properties of the various aircraft remain over the total simulation period of 6 h. The total extinctions of A380‐produced contrails are about 1.5 to 2.5 times higher than those from contrails of a Bombardier CRJ.

Design of a non-homogeneous differentiator for actuator oscillatory failure case reconstruction in noisy environment

This work addresses the problem of oscillatory failure case detection in the electrical flight control system of a generic commercial airplane. A non-homogeneous differentiator is first used to provide accurate derivatives in noisy environment and fast convergence time. In this study case, fault detection is addressed in the unknown input estimation issue for fault reconstruction with the same evaluation techniques currently employed in Airbus A380 airplanes. Based on the non-homogeneous differentiator theory, an algorithm for differentiator tuning is provided to manage a trade-off between the accuracy of fault reconstruction and the convergence time that is compliant with specified detection time requirements. Performance and robustness of the developed monitoring strategy are assessed using a high-fidelity Airbus benchmark and a parametric test campaign for the flight scenarios defined in the EU-FP7 ADDSAFE project.

Adaptive Processes for the Aircraft Engines of Tomorrow

AbstractAmong the public's favorites at the ILA Berlin Airshow were the future “stars in the heavens“, such as the Airbus A350 XWB. Rather inconspicuous, but equally spectacular were the manufacturing technologies applied to create more efficient jet engines, which the Fraunhofer researchers, represented by the Innovation Cluster AdaM, displayed in Berlin.

Effect in the high modulus asphalt concrete with the temperature

The use of the high modulus asphalt concrete in the base course of airport pavements is not of recent utilization, but at present there is a considerable gap in the regulation for the use of this bitumen. The main objective of this paper is to present the results of the research that has been done using the experimental dynamic modulus of different mixtures of conventional bitumen with different penetration index B40/50, B60/70, B100/150, B150/200 and the high modulus bitumen B13/22 to calculate the percentage of reduction in thickness of the base course in airport pavements when is used High Modulus Asphalt Concrete (HMAC) compare with conventional bitumen mixtures and is also taken into account the temperature. In order to obtain the reduction in thickness depending on the temperature and the use of HMAC, the tests have been performed at the different temperatures −20°C, −10°C, 0°C, 10°C, 20°C and all the results in this paper are presented for these temperatures.To perform the calculations of this research the Airbus A380 has been taken as Aircraft Design.

The Duration of Automation Bias in a Realistic Setting

Whereas in most studies conducted previously the effect of automation bias has been investigated in terms of an instantaneous decision, this study is aimed at quantifying its duration. Automation bias is modeled as a stochastic process using a unimodal log-log probability distribution. To validate the model, an experiment using an Airbus A320 fixed-base flight simulator with a malfunction on the auto-throttle was executed with 35 licensed pilots. The effect of pilot experience is investigated; results show that less experienced pilots are on average less sensitive to automation bias but have more variation in performance than more experienced pilots.

Wireless data transmission using visual codes

In this paper, a new approach for wireless data transmission within an aircraft cabin is presented. The proposed application enables the transmission of data to a passenger’s user device. As wireless in-flight applications are subject to strict frequency and electromagnetic compatibility (EMC) regulations, the data is transferred by optical wireless transmission, specifically by two-dimensional visual codes. To this end, black-and-white or colored visual code sequences are displayed on the in-flight entertainment screen. These visual codes are captured by the built-in camera of the passenger’s mobile device and are decoded to reconstruct the transmitted data. In order to compensate for frame losses caused by effects like occlusion and motion blur, a temporal forward error correction coding scheme is applied. Transmission experiments within an Airbus A330 cabin mock-up demonstrate the functionality of the implemented system under realistic conditions such as ambient illumination and geometric configuration. Representative user devices are used for evaluation; specifically, a low-cost and a high-end smartphone are employed as receivers. Performance evaluations show that the proposed transmission system achieves data rates of up to 120 kbit/s per individual passenger seat with these user devices. As the user device has no physical connection to the sensitive on-board system, the proposed transmission system provides an intrinsic safety feature.

Damage assessment of nuclear containment against aircraft crash

The behavior of nuclear containment structure has been studied against aircraft crash with an emphasis on the influence of strike location. The impact locations identified on the BWR Mark III type nuclear containment structure are mid-height, junction of dome and cylinder, crown of dome and arc of dome. The containment at each of the above locations has been impacted normally by Phantom F-4, Boeing 707-320 and Airbus A320 aircrafts. The loading of the aircraft has been assigned through the corresponding reaction-time response curve. ABAQUS/Explicit finite element code has been used to carry out the three-dimensional numerical simulations. The concrete damaged plasticity model was used to simulate the behavior of concrete while the behavior of steel reinforcement was incorporated using the Johnson–Cook elasto-viscoplastic material model. The mid-height of containment has been found to experience most severe deformation against each aircraft. Phantom F4 has been found to be most disastrous at each location. The results have been compared with those of the available studies with respect to the containment deformation.