Viewing 1 to 30 of 2170
Technical Paper
Robert J. Flemming, Philip Alldridge
Sikorsky Aircraft certificated the Model S-92A™ helicopter for flight in icing conditions in 2005. Since that time, the aircraft has flown in icing conditions throughout the world and the approval to launch a flight when icing conditions are forecast or reported has been valuable to operators. However, when the rotor ice protection system was inoperative due to a system failure, use of the aircraft on days of forecast icing was prohibited. Sikorsky Aircraft, therefore, elected to obtain certification of the S-92A helicopter to an EASA limited icing Special Condition so that UK and Norwegian operators in the North Sea sector could complete a mission when icing conditions were forecast, should the RIPS be inoperative on that day. A review of previously available icing data indicated that the S-92A helicopter could meet the requirements of the EASA Special Condition, but that additional flights were required to demonstrate full compliance.
Technical Paper
John P. Dow, Sr., Cristhian N. Aliaga, Shoaib Shah, Jian Chen, Wagdi G. Habashi, John L. Siemens
CFD-Icing (CFD-I) is a powerful companion to CFD-Aero (CFD-A) in the design and certification of new aircraft, rotorcraft and jet engines. It can drastically reduce the number of tunnel and flight tests, and their associated costs, by simulating on computers the full Appendix C and beyond such as is proposed in new Appendices D and O. It can also predict performance and moment coefficients in roll, pitch and yaw. These predictions can then be used in original certification or supplemental certifications to the type design, allowing mitigating potential hazards of flight-testing. This work presents an example of the application of FENSAP-ICE to predict 45 minutes of ice accretion on a RC-26B aircraft fuselage retrofitted by the addition of a FLIR sensor and a SATCOM antenna. The predicted aerodynamic penalties are compared with recorded flight test data obtained with simulated ice shapes.
Technical Paper
Luc Marcil
This white paper explains the benefits of the Model-Based Design (MBD) approach and Object-Oriented Technology (OOT) that DO-178C provides. It also specifically focuses on the usage of Models and COTS Qualifiable tools that automate or facilitate the verification and validation of avionics applications constructed from Models in order to ensure that there is no unintended function. Software running in Aircraft cockpits has dramatically increased in complexity since DO-178B's revision in 1992. Furthermore, over the past 20 years, software development methods have made significant leaps forward and DO-178B has begun to show its age with respect to the new technology introduced to facilitate software development. This year the newly revamped DO-178C standard sets the certification process record straight by embracing modern technology.
Technical Paper
Roland Wolfig
The Time-Triggered Architecture (TTA) and its software development environment for the Time-Triggered Protocol (TTP) provide a framework which allows the efficient development of distributed embedded applications. Separate development of system architecture and subsystems design, strict control of key system interfaces and separation of functional/logical from temporal behavior facilitate the reuse and seamless integration of electronic subsystems provided by different suppliers. TTA is an integrated platform solution which allows modular application development and certification up to the highest criticality classes with reuse of components. TTA principles improve the ability of system designers to significantly reduce system integration effort and obsolescence management costs. The time-triggered communication protocol TTP provides high performance and fault tolerance for the data transfer between distributed applications.
Technical Paper
Rebecca Menes, Herbert Hecht
Certification of UAVs reopens the issues of certification of software-heavy critical systems. Current practices are both costly and unable to ensure full coverage of failures. We propose to revisit the FMEA (Failure Modes and Effects Analysis) as a framework for streamlining certification of critical software systems. Using object oriented design environments we have shown that not only is the FMEA an effective framework for certification, but that we were able to automate a large part of the effort. The resulting certification process is both cost effective and verifiable. We provide an example of this method.
Technical Paper
Barry Hendrix, Michael F. Siok
The purpose of this technical paper and associated SAE panel discussion is to present an overview of software safety and technical integrity needs for “new” aircraft and software intensive systems development. Most of the software safety and integrity concepts presented are already proven and accepted in the commercial aircraft domain and are becoming more widely accepted for military tactical and strategic airlift aircraft. Even newer fighter/attack systems now accept the need for safety-critical functions list and more software safety focus. The focus is on effective, efficient, and essential software safety processes and modern methodologies to ensure safety-critical functions, either commanded, controlled or monitored by software, are prevented from contributing to Catastrophic and Hazardous failure conditions and resultant hazards.
Technical Paper
Rafi Yoeli
Compared to helicopters, the safety and operational advantages of ducted fan VTOL vehicles that do not rely on large, exposed rotors overhead seem promising. The alternative to the overhead rotor that naturally comes to mind is a smaller, enclosed rotor or multitude of rotors, sometimes referred to as ‘fans’, or, in combination with their enclosure, ‘ducted fans’. During the 50's and 60's, numerous experimental VTOL vehicles were developed, that relied on ducted fans as their main source of lifting power. The experience with the early vehicles was marginal, both in terms of the propulsive efficiencies attained, as well as stability and control problems caused among others by the ducted fan's inherent sensitivity to wind gusts. Today, with the advent of higher efficiency engines and fly-by-wire flight control systems, ducted fan vehicles are again being considered as a potential method for providing a safer, more compact alternative to the traditional helicopter.
Technical Paper
Fabio Saunier Martins, Luiz Augusto Rodrigues Nerosky, Felipe Eudes Pontes Fernandez, José Carlos Silva Menezes Senna
The ETOPS (Extended Range Operation with Two Engine Airplanes) certification is required for two engine airplanes which operate over a route that contains a point farther than one hour flying time at the normal one-engine inoperative cruise speed from an adequate airport. ETOPS regulations are applicable to routes over water as well as remote land areas. This paper summarizes the ETOPS certification process for Commercial Aircraft, including the following topics: Brief ETOPS history; Scope and Applicability; Regulations and Guidelines Applicable for ETOPS Certification; Relevant Aircraft Manufacturer Activities; Aircraft Operator Responsibilities
Technical Paper
Eduardo de Castro Faustino Coelho
Abstract Modern aircraft make use of several electronic systems; some of these systems have functions that are critical for flight safety. The aerospace community is aware that strong radiated signals, like those generated by telecommunication or air traffic control systems may be so severe that could be able to upset these flight safety critical systtems. So, aircraft manufacturers must provide means to reduce the amount of RF power that can penetrate the aircraft systems, and then minimise the probability of disasters caused by high intensity radiated fields. Thus, certification of aircraft in HIRF is a challenge to modern mobility engineering. The certification test in HIRF is so complex and expensive that its repetition os prohibitive. Furthermore, this kind of test is only appliable during final developing phases of a new aircraft model. So, the designers must include effective HIRF protections to critical systems.
Technical Paper
Adam Brown
The paper reviews the current status of flight test, certification and in-service experience with the latest members of the Airbus Industrie commercial aircraft family - the A330, A340 and A321 - as well as efforts under way throughout the Airbus system to improve the efficiency of its manufacturing business performance, including the development of a new, highly productive tool, the Airbus Super Transporter.
Technical Paper
Jerry T. Blair
Concern over the effects of High Intensity Radiated Fields (HIRF) on civil and military aircraft has increased over the past ten years. The increase is due to several factors which affect the safe flight of all fixed-wing and rotorcraft. Previous flight-critical mechanical controls are being replaced by electronic computer-driven controls, manufacturers are increasing the use of composite materials in the fabrication of new aircraft structures, and frequency ranges and output power levels of commercial and military transmitters have significantly increased. While much HIRF susceptibility information has been collected, the data are proprietary and have not been released. To address the HIRF concerns and begin development of a releasable HIRF database, the FAA Technical Center, Atlantic City International Airport, NJ, has implemented a HIRF research program. As part of that program, a HIRF test was performed on a Sikorsky S-76 Helicopter.
Technical Paper
F. Bruce Metzger, John S. Preisser
This paper reviews the status of analytical and empirical propeller noise prediction methods with specific emphasis on those that are suitable for General Aviation propellers. Specifically, the paper reviews the capabilities and limitations of methods that are simple enough for ease of use by industry while providing sufficient accuracy to guide the development of new propeller designs or the modification of existing propeller driven airplanes to satisfy increased certification stringency or cabin comfort objectives.
Technical Paper
Alex P. Schust, Kimberly T. Joyce
Aircraft capability and performance are major factors to consider in establishing lateral, vertical, and longitudinal separation standards for air traffic control. This paper addresses how vertical aircraft performance can be assessed by analyzing data from sources such as airworthiness certifications, height-measuring radar data collections, manufacturer bench tests, and related aircraft programs. Such an assessment is necessary before certifying authorities will approve aircraft types or individual airframes for operational use in the new separation standard airspace.
Technical Paper
Alex P. Schust, Brian Colamosca
This paper presents a discussion of how aircraft altitude measurement standards were developed by the Federal Aviation Administration for the International Civil Aviation Organization (ICAO) through a combination of altimetry system error measurements by aircraft type and statistical analysis of individual aircraft type performance. The paper presents an analysis that supports the assumption that altimetry system error (ASE) by aircraft type is Gaussian and shows that if ASE is not truly Gaussian but approaches Guassian there is a relatively small effect on the setting of altitude measurement standards. Altimetry system standards are developed by creating a parametric relationship between altitude keeping (how well assigned flight level is flown) and altitude measurement (how well altitude is measured by the altimetry system).
Technical Paper
Tom DeFiore, Terence Barnes
As a part of its International Aging Aircraft Research Program, the Federal Aviation Administration is establishing a state-of-the-art Flight Loads Data Collection Program. Data collected in this program will provide the necessary mission profiles and load spectra information to characterize typical fleet service usage for the regional/commuter service life extension program. In addition, these data are applicable for both a safe life fatigue analysis and a damage tolerance fracture mechanics analysis. This paper describes the FAA approach and schedule for instrumenting fleet service aircraft, and the data reduction process.
Technical Paper
Paolo Cinquetti, Sergio Martini
Abstract The icing tests carried out on the Piaggio P.180 “Avanti” aircraft throughout development and certification program are herein described from preliminary evaluation in wind-tunnel tests to real flight in artificial icing conditions realized behind U.S. Air Force air tanker NKC-135 and, finally, to natural ice tests performed in a wide range of atmospheric environments comprehensive of a wide range of average liquid water contents, cloud droplets median volume diameter and static temperature obtained in significant icing conditions. Slight discrepances between data in artificial and natural tests have been discovered and herein discussed.
Technical Paper
Noel B. Sargent
Avionic systems performing critical functions in modern aircraft are potentially susceptible to the hazards of electromagnetic radiation from ground and airborne transmitters. The Federal Aviation Administration (FAA) requested that the Society of Automotive Engineers (SAE) coordinate the development of procedures and guidance material which can be used during the aircraft certification process to ensure adequate protection against High Intensity Radiated Fields (HIRF). This paper addresses the technical challenge of drafting a certification procedure and guidance standard, and the management process used by the SAE subcommittee AE4R to converge a diverse range of opinions by its international membership in the shortest possible time.
Technical Paper
Branko Sarh
This paper addresses the design principles inherent in past flying automobiles and describes needed methodology for the development of future more advanced flying automobile concepts, emphasizing customer's needs and system requirements. The general aviation industry was analyzed and reasons for their stagnation/decline discussed. A proposal for a new private transportation system encompassing ground guided airways and its advantages for the private future air transportation are presented.
Technical Paper
J. Anderson Plumer, Jean-Patrick Moreau, Richard F. Hess
A proposed revision of FAA Advisory Circular AC 20-136 was developed by EUROCAE Working Group 31 and SAE Committee AE4L to address requests by some users of this FAA advisory circular for more specific guidance for selection of equipment transient design levels (ETDL’s) applicable to electrical and avionic systems performing essential or critical functions, and for selection of verification methods for these systems. The proposed revision also makes use of the expanded data base of measured induced transient levels in aircraft since publication of the original draft advisory circular in the United States in 1987 (the original “Orange Book”), to enable descriptions of aircraft interconnecting wiring installations corresponding to each of the standard transient levels.
Technical Paper
Patrick C. Scott
Over the last 5 years a set of certification requirements for transport category aircraft have been developed by the Federal Aviation Agency and the Joint Aviation Authorities for lightning strike protection. Those requirements were jointly developed by a cooperative effort between industry and regulators attending a series of committee meetings sponsored by SAE and the ARAC. Within the last two years, the regulatory agencies have recognized a need to address the continued airworthiness of lightning protection devices installed on transport category aircraft to meet these certification requirements.
Technical Paper
Johnny T. Doo, Timothy W. Graf, George R. Hicks, Paul E. Romano
The SJ30-2 is a high performance, entry level business jet with the design goal of offering performance superior to other aircraft in its class. Critical data were obtained and evaluated early in the development program through flight and structural testing of a prototype aircraft. Prototype testing helped to achieve aggressive design goals and minimized potential design changes for the globally located manufacturing team. This prototype based approach reduced the program schedule risk in the production and certification phase.
Technical Paper
J. Paul Sims
This paper provides an overview of the engineering modifications and the regulatory requirements to convert a U.S. registered aircraft for European operations as a freighter. The paper outlines the steps taken and the equipment installed to meet Joint Airworthiness Regulations (JAR) and German Luftfahrt-Bundesamt (LBA) regulations by the author.
Technical Paper
Leo Janssens, Ralph D. Kimberlin
This paper discusses the Micco spin flight test program for the FAA Part 23 certification of the MAC-145A and the MAC-145B light single engine aircraft. The 145A was awarded FAA certification in January 2000 in the Utility Category (spins prohibited in operation use). Approximately 120 one turn spins were completed in the flight test program with no anomalies or safety incidents. The 145B, and increased power derivative of the 145A, was intended to be immediately certified in the Acrobatic Category which permits spins and acrobatic maneuvers. However, spin flight tests of approximately 210 spins revealed that the 145B, in its current configuration, could not meet the Acrobatic Category recovery criteria for multiple turn spins. It is now intended to certify the 145B in the Utility Category (spins prohibited) until further modifications and flight tests can be completed.
Technical Paper
Hanna Czarnecki, Zdzislaw Klim
Aircraft systems are designed with reliability, safety and cost effectiveness in mind. The certification of the aircraft is based on tests and results of theoretical analyses that show the compliance with the FAR/JAR requirements. Monitoring for safety for in-service aircraft is an important, critical and extremely complex process. The ultimate objective is to assure that the safety level is equal to the original estimate or better. The manufacturer of the aircraft is particularly responsible for overall monitoring and assessment of all safety related events and corrective actions. Many different philosophies were adopted for this purpose. The safety monitoring and audit strategy is generally based on experience, engineering judgment, event analysis and numerical quantification by using probability theory and statistical tools. The aircraft sequential entry in the service and the aging of their components lead to the non-homogeneity of the fleet.
Technical Paper
Thomas M. Hermann, Michael W. Holmes, Dayton Hartley
The development of a dynamic aircraft seat analysis is presented in this paper. This analytical model is a nonlinear finite element model composed of a seat frame and cushion, restraint system, glare shield and a rigid body model of a 50th percentile Hybrid-II anthropomorphic test dummy (ATD) occupant. Results from this analytical model are correlated with empirical results obtained during a full-scale dynamic test. The analysis is representative of the dynamic test.
Automation leads advances in aerospace composites usage Increased productivity is the focus of today's automation for composites made of carbon-fiber reinforced plastics.
Technical Paper
Olaf Spiller
One of the tasks to show compliance with the relevant requirements for protection against the effects of lightning on an aircraft is to derive the so-called internal environment. Of the methods available to determine the transfer functions from the specified external lightning environment to the aircraft specific internal environment, low level swept CW testing offers benefits over the high level or low level pulse injection methods. The paper looks at the way an actual test was conducted on the EADS Airbus Advanced Technology Demonstrator (ATD) testbed aircraft, a VFW614 model. This aircraft has been heavily modified to fly with an Electronic Flight Control System EFCS. The test is performed to determine the Transient Control Levels (TCL) and establish the Equipment Transient Design Levels (ETDL) for the new equipment.
Technical Paper
Norman F. Harpur
The certification of the Concorde SST has presented a new challenge to the manufacturers and to the certification authorities in the United Kingdom, France, and the United States of America. Apart from the need to ensure, for an advanced type of civil aircraft, a level of airworthiness at the time of entry into service at least as good as current subsonic jets, many new technical and administrative problems have had to be dealt with. For the first time in aeronautical history the certification authorities from three nations, together with an integrated organization of four manufacturers (British Aircraft Corporation, Aerospatiale, Rolls-Royce, and Snecma) in two countries, have been involved in the drafting and application of new requirements for a new type of aircraft. The main problems, both technical and administrative, are dealt with in this paper, together with a brief reference to the current status of Concorde Certification.
Technical Paper
Don M. Archibald
The certification of an aircraft has progressed from demonstrations which were performed entirely upon the first-flight article to those in recent years which apply varying degrees of ground-based test facilities (simulators). The extent of these test facilities has been influenced by the complexity of the aircraft and the aircraft systems, the individual manufacturer's development philosophy and the funding allocated to simulation. This paper, based primarily on the development and certification of the Lockheed L-1011, concludes that increased simulation to show compliance is not only possible but in many instances is cost effective as well. This conclusion is based on a review of the requirements set down by FAR 25, the methods used to certify the L-1011 and the relative costs of compliance demonstration by flight testing and simulation. The present industry trend towards the derivative aircraft is making the argument for increased simulation for certification even stronger.
Technical Paper
Hamid M. Lankarani, Cheong-Choon Ng
The Federal Aviation Administration (FAA)'s analysis of commuter aircraft accidents and ongoing research has indicated that the crashworthiness capabilities of smaller aircraft may be questionable. The small size of these aircraft results in a stiff structure and consequently higher impact loads experienced by the occupants. In 1993, the FAA issued a Notice of Proposed Rule Making (NPRM) 93-71 to increase the deceleration pulse amplitude of the sled tests under the Test-1 conditions (60-degree test) to 32G for the commuter type aircraft. To meet this condition, the seat design must exploit the energy absorption potential for its structural components. Energy absorbing components may include the seat legs, seat pan, and seat cushion. The intent is to design the seat so that it strikes well beyond the elastic limit to absorb the energy of the impact. To date, no seat has yet been able to pass the proposed criteria with an acceptable limit on the lumbar load (1500 pounds).
Viewing 1 to 30 of 2170


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