A320 Aircraft Research Articles

Cut Set Analysis using Behavior Trees and model checking

Abstract Safety analysis can be labour intensive and error prone for system designers. Moreover, even a relatively minor change to a system’s design can necessitate a complete reworking of the system safety analysis. This paper proposes the use of Behavior Trees and model checking to automate Cut Set Analysis (CSA) : that is, the identification of combinations of component failures that can lead to hazardous system failures. We demonstrate an automated incremental approach to CSA, in which models are extended incrementally and previous results incorporated in such a way as to significantly reduce the time and effort required for the new analysis. The approach is demonstrated on a case study concerning the hydraulics systems for the Airbus A320 aircraft.

Cockpit door module for A380 and AXP A340 aircraft.

The cockpit door module for the A380 and A340 aircraft was assessed for specification compliance. Per the manufactures specifications, the noise/vibration levels exceeded performance specifications at various frequencies during the testing phases. Each noise contributor in the overall system was identified evaluated and assessed. The real world practical application of active/passive noise control was utilized in a superposition system. Due to strict FAA requirements, multiple paths of mitigation measures were explored. Mitigation measures include product redesign, material design, absorptive material, and constrained layer damping technology. Noise measurements were conducted to assess the results of the migration efforts. The data and results of this assessment are presented and discussed.

Inductive Sensor for Lightning Current Measurement, Fitted in Aircraft Windows—Part II: Measurements on an A320 Aircraft

A novel sensor for the detection of the lightning current through the fuselage of an aircraft has been tested on an A320 aircraft. An accurate method-of-moment model of the window edge provided reliable calibration of the sensor for external fields. The data have been analyzed and the good performance of the sensor in sensitivity and bandwidth is demonstrated.

Active Flow Control Systems Architectures for Civil Transport Aircraft

This paper considers the effect of choice of actuator technology and associated power systems architecture on the mass cost and power consumption of implementing active flow control systems on civil transport aircraft. The research method is based on the use of a mass model that includes a mass due to systems hardware and a mass due to the system energy usage. An Airbus A320 aircraft wing is used as a case-study application. The mass model parameters are based on first-principle physical analysis of electric and pneumatic power systems combined with empirical data on system hardware from existing equipment suppliers. Flow control methods include direct fluidic, electromechanical-fluidic, and electrofluidic actuator technologies. The mass cost of electrical power distribution is shown to be considerably less than that for pneumatic systems; however, this advantage is reduced by the requirement for relatively heavy electrical power management and conversion systems. A tradeoff exists between system power efficiency and the system hardware mass required to achieve this efficiency. For short-duration operation the flow control solution is driven toward lighter but less power-efficient systems, whereas for long duration operation there is benefit in considering heavier but more efficient systems. It is estimated that a practical electromechanical-fluidic system for flow separation control may have a mass up to 40% of the slat mass for a leading-edge application and 5% of flap mass for a trailing-edge application.

Supply of seals to Airbus approved

Meggitt Polymer Solutions (MPS) has received supplier approval from Airbus and has commenced shipment of products for the A330 and A340 aircraft.

Particle and Gaseous Emissions from Commercial Aircraft at Each Stage of the Landing and Takeoff Cycle

A novel technique was used to measure emission factors for commonly used commercial aircraft including a range of Boeing and Airbus airframes under real world conditions. Engine exhaust emission factors for particles in terms of particle number and mass (PM2.5), along with those for CO2 and NOx, were measured for over 280 individual aircraft during the various modes of landing/takeoff (LTO) cycle. Results from this study show that particle number, and NOx emission factors are dependent on aircraft engine thrust level. Minimum and maximum emissions factors for particle number, PM2.5, and NOx emissions were found to be in the range of 4.16 x 10(15)-5.42 x 10(16) kg(-1), 0.03-0.72 g.kg(-1), and 3.25-37.94 g.kg(-1), respectively, for all measured airframes and LTO cycle modes. Number size distributions of emitted particles for the naturally diluted aircraft plumes in each mode of LTO cycle showed that particles were predominantly in the range of 4-100 nm in diameter in all cases. In general, size distributions exhibit similar modality during all phases of the LTO cycle. A very distinct nucleation mode was observed in all particle size distributions, except for taxiing and landing of A320 aircraft. Accumulation modes were also observed in all particle size distributions. Analysis of aircraft engine emissions during LTO cycle showed that aircraft thrust level is considerably higher during taxiing than idling suggesting that International Civil Aviation Organization (ICAO) standards need to be modified as the thrust levels for taxi and idle are considered to be the same (7% of total thrust) (Environmental Protection, Annex 16, Vol. II, Aircraft Engine Emissions, 2nd ed.; ICAO--International Civil Aviation Organization: Montreal, 1993).

Some cosmic radiation dose measurements aboard flights connecting Zagreb Airport

When primary particles from space, mainly protons, enter the atmosphere, they produce interactions with air nuclei, and cosmic-ray showers are induced. The radiation field at aircraft altitude is complex, with different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. The non-neutron component of cosmic radiation dose aboard A320 and ATR40 aircraft was measured with TLD-100 (LiF:Mg,Ti) detectors and the Mini 6100 semiconductor dosimeter; the neutron dose was measured with the neutron dosimeter consisted of LR-115 track detector and boron foil BN-1 or 10B converter. The estimated occupational effective dose for the aircraft crew (A320) working 500 h per year was 1.64 mSv. Another experiment was performed at the flights Zagreb–Paris–Buenos Aires and reversely, when one measured non-neutron cosmic radiation dose; for 26.7 h of flight, the MINI 6100 dosimeter gave an average dose rate of 2.3 μSv/h and the TLD dosimeter registered the dose equivalent of 75 μSv or the average dose rate of 2.7 μSv/h; the neutron dosimeter gave the dose rate of 2.4 μSv/h. In the same month, February 2005, a traveling to Japan (24-h-flight: Zagreb–Frankfurt–Tokyo and reversely) and the TLD-100 measurement showed the average dose rate of 2.4 μSv/h; the neutron dosimeter gave the dose rate of 2.5 μSv/h. Comparing dose rates of the non-neutron component (low LET) and the neutron one (high LET) of the radiation field at the aircraft flight level, we could conclude that the neutron component carried about 50% of the total dose, that was near other known data.

Investigation into the use of low cost MEMS accelerometers for vibration based damage detection

When a structure is damaged there is often a concomitant localized change in structural stiffness, which may affect the dynamic characteristics of the structure. One characteristic that has proved suitable for damage identification and location is the operational curvature shape which exhibits changing features at locations of stiffness change. A method that finds theses features, SIDER, employs an algorithm that operates on broadband operational curvature shapes. To obtain data for SIDER, a small number of accelerometers, typically about four, is installed on the structure and the structure is then excited at a large array of test points using a ‘roving hammer’ technique. Frequency response functions are individually measured between each excitation point and the reference accelerometers, and the required operating curvature shapes are determined from the resulting array of frequency response functions. While setup of the experiment is reasonably quick, data acquisition can be time consuming and it is not easily amenable to automation. This paper investigates an alternative approach, which relies on the reciprocity theorem. An array of response transducers is installed on the structure, and then only a few locations are excited. There are significant benefits to this method, including the possibility of automation and remote sensing. The cost of hundreds of conventional accelerometers can be prohibitive, and therefore this project investigated using an array of low cost MEMS accelerometers. MEMS are also attractive in that they may be embedded into a composite structure during manufacture. In the study reported here the roving hammer and MEMS array methods are compared by testing a composite vertical stabilizer (tail plane) from an Airbus A320 aircraft. Despite the different test procedures, and the lower quality of the MEMS transducers, it is shown that an array of low cost MEMS transducers can determine results comparable with those obtained using high performance transducers.

Tropopause referenced ozone climatology and inter-annual variability (1994–2003) from the MOZAIC programme

Abstract. The MOZAIC programme collects ozone and water vapour data using automatic equipment installed on board five long-range Airbus A340 aircraft flying regularly all over the world since August 1994. Those measurements made between September 1994 and August 1996 allowed the first accurate ozone climatology at 9–12 km altitude to be generated. The seasonal variability of the tropopause height has always provided a problem when constructing climatologies in this region. To remove any signal from the seasonal and synoptic scale variability in tropopause height we have chosen in this further study of these and subsequent data to reference our climatology to the altitude of the tropopause. We define the tropopause as a mixing zone 30 hPa thick across the 2 pvu potential vorticity surface. A new ozone climatology is now available for levels characteristic of the upper troposphere (UT) and the lower stratosphere (LS) regardless of the seasonal variations of the tropopause over the period 1994–2003. Moreover, this new presentation has allowed an estimation of the monthly mean climatological ozone concentration at the tropopause showing a sine seasonal variation with a maximum in May (120 ppbv) and a minimum in November (65 ppbv). Besides, we present a first assessment of the inter-annual variability of ozone in this particular critical region. The overall increase in the UTLS is about 1%/yr for the 9 years sampled. However, enhanced concentrations about 10–15 % higher than the other years were recorded in 1998 and 1999 in both the UT and the LS. This so-called "1998–1999 anomaly" may be attributed to a combination of different processes involving large scale modes of atmospheric variability, circulation features and local or global pollution, but the most dominant one seems to involve the variability of the North Atlantic Oscillation (NAO) as we find a strong positive correlation (above 0.60) between ozone recorded in the upper troposphere and the NAO index. A strong anti-correlation is also found between ozone and the extremes of the Northern Annular Mode (NAM) index, attributing the lower stratospheric variability to dynamical anomalies. Finally this analysis highlights the coupling between the troposphere, at least the upper one, and the stratosphere, at least the lower one.

Kalman filter and neural network‐based icing identification applied to A340 aircraft dynamics

PurposeThe purpose of this paper is to maintain safe flight and to improve existing deicing (in‐flight removal of ice) and anti‐icing (prevention of ice accretion) systems under in‐flight icing conditions.Design/methodology/approach – A recent academic research on aircraft icing phenomenon is presented. Several wind tunnel tests of an experimental aircraft provided by NASA are used in the neural network training. Five ice‐affected parameters are chosen in the light of these experiments and researches. An offline artificial neural network is used as an identification technique. The Kalman filter is used to increase the state measurement's accuracy such that neural network training performance gets better. A linear A340 dynamic model is selected in cruise conditions. This linear model is simulated in time varying manner in terms of changing icing parameters in a system dynamic matrix. The obtained data are used in neural network training and testing.Findings – Airframe icing can grow in many ways and many points on aircraft. In this research, wing leading edge ice occurrence is only considered at the same level in both left and right wings. During ice growth other faults or anomalies are ignored.Originality/value – Existing icing sensors can only provide an indication about possible ice presence. They cannot give information of the exact level of ice. However, the efficiency of current control system of changed model decreases. The proposed technique offers a method to find out the model changes under icing conditions.

David Neeleman, CEO of JetBlue Airways, on people + strategy = growth

Executive Summary JetBlue Airways began operations in February 2000 from its base at New York's John F. Kennedy International Airport and now, four years later, serves 22 cities across the U.S. with a fleet of 48 new Airbus A320 aircraft. As CEO of JetBlue Airways, David Neeleman has launched his third successful aviation business and is realizing his desire to bring humanity back to air travel by offering passengers low fares, friendly service, and a high-quality product. Neeleman's career in the airline industry began in 1984 when he co-founded a low-fare carrier called Morris Air with June Morris, the owner of Salt Lake City-based travel agency Morris Travel. As president of Morris Air, David implemented the industry's first electronic ticketing system and pioneered a home-reservationist system that is now the foundation of JetBlue's unique call center: all calls to JetBlue's reservation number are handled by reservationists working out of their homes. Following the sale of Morris Air and a short period with Southwest Airlines, Neeleman took the electronic ticketing system that he had initiated at Morris Air and developed it into Open Skies, the world's simplest airline reservation system. Neeleman sold Open Skies to Hewlett-Packard in 1999. Also during this period, Neeleman acted as a consultant to WestJet Airlines, the successful Canadian low-fare start-up airline. In 1999, after the conclusion of his five-year non-compete agreement with Southwest Airlines, Neeleman decided the time was right to bring his successful airline formula— innovative, high-quality service plus low fares equals a strong and loyal market—fo one of the country's largest aviation markets: New York City. He assembled a hand-picked management team of airline industry veterans and secured $130 million in capital funding from investors such as Weston Presidio Capital, George Soros, and Chase Capital, now JP Morgan. In 2003, for the second consecutive year, JetBlue was rated “Best Domestic Airline” at Conde Nast Traveler's 2003 Readers' Choice Awards and was runner-up for “Best Domestic Airline” at Travel & Leisure magazine's 2002 and 2003 World's Best Awards. David lives with his wife Vicki and their nine children in New Canaan, Connecticut.

MOZAIC: five in-service airbus A340s evaluate impact of air traffic on atmosphere

Aircraft emissions are likely to have their greatest effect upon the atmosphere and climate when discharged near the junction of the troposphere and the stratosphere. To measure the effects of air traffic in that region of the atmosphere, a number of in-service Airbus A340 aircraft have been fitted with automatic measuring and recording equipment. Already more than 95 000 hours of observations have been recorded. This article describes this work and plans for the future.

“A 320 HLF Fin” flight tests completed

On September 17, 1998, another Airbus-first happened - the first flight of an A320 aircraft with a hybrid laminar flow (HLF) fin. This report gives an overview of the programme as part of an overall European research activity on the technology with the highest fuel saving potential Laminar Flow.

A family of fault-tolerant systems: electrical flight controls, from Airbus A320/330/340 to future military transport aircraft

The aim of this paper is to describe the Airbus fly-by-wire systems from a fault-tolerant standpoint. The Airbus fly-by-wire basic principles are presented first. Then follows the description of the main system features common to A320 and A340 aircraft, the failure detection and reconfiguration procedures, the A340 particularities, and the design, development and validation procedures. Future trends in terms of fly-by-wire fault-tolerance conclude this overview.

Aerospace Production

Chadderton, England — the home of British Aerospace PLC (BAe), the British company which plays an important role in the Airbus project as designer and builder of the wings for A300, A310, A320 and A340 aircraft. The wings are designed at BAe, Filton, prior to machining at Chadderton, following which assembly is undertaken at BAe in Chester. The company has a one‐fifth share in the Airbus business representing £1 billion turnover and with orders and deliveries for the aircraft approaching 900, the importance of Airbus to the plant is continuing to increase.

Reliability evaluation of fly-by-wire computer systems

Computer systems that are used for critical applications are designed to tolerate both software and hardware faults by executing multiple software versions on redundant hardware. This integrated approach to fault tolerance is difficult to analyze using existing techniques that consider hardware and software separately. In this article, a combination of fault trees and Markov models are used to provide an integrated analysis of a portion of the flight control systems used on the Airbus A310 and A320 aircraft. The goal of the analysis is to determine the reliability of each system, that is, the time-dependent probability of producing an acceptable result. An unacceptable output can be the result of hardware or software faults that are not tolerated by the level of redundancy provided.

Equipment

Aircraft Porous Media Europe Ltd. (APME) have been selected to supply the cabin air recirculation filters for the Airbus A330 and A340 aircraft. Together with the sister company Pall Land and Marine Corporation (PLM), who have been selected to supply filters for the B747‐400, B777 and MD11 cabin air systems, the Pall Aerospace group now supply the environmental system filtration requirements of all major long range aircraft programmes.

Contracts

EVENDALE, Ohio — CFM International's CFM56–5 engine has been selected by Gulf Air to power 12 firm, 6 option Airbus Industrie A320 aircraft in an engine order valued at more than S225 million.

Fault-tolerant systems

Two mishaps early this year forcefully reminded the authors how important computer systems' reliability has become to human well-being in this last decade of the 20th century. In January, large parts of AT&T's long-distance telephone switching networks failed because of a software problem. Then, in February, a 'fly by wire' Airbus A320 aircraft crashed in Bangalore, India. While a definitive cause for the accident has yet to be established (preliminary investigations suggest that the control computers might well have performed to specifications), the fact that the A320 employs a fully electronic cockpit with no mechanical backup for control has raised much speculation about the computers' role in the crash. The authors stress that the basic idea behind building in a fault tolerant capability is to provide the system with extra (redundant) resources. >

Contracts

British Caledonian Airways (‘BCal’) have signed a contract worth, with options, £1.1 million for the Galley Systems for its new Airbus A320 fleet with its selected Supplier, Henshalls Ltd. of Byfleet, Surrey. The Gatwickbased Airline was a lauch Customer for the type and will be taking seven A320 aircraft into its European fleet in 1988 and '89, with options on a further three.