Certification Basis Research Articles

Clarifying Ambiguity in Aircraft Regulatory Documentation: A Review of Modeling Approaches

Aircraft design and development programs must comply with many certification requirements described in natural language provided in a complex collection of document-based regulations and associated guidance material. As a result, individual design organizations develop internal processes detailing how regulatory requirements should be met within their aircraft design programs. Subject matter experts develop these processes, which are subjective interpretations of the regulations and can vary significantly between development programs and organizations. Model-based approaches are increasingly used to manage the complexity of the aircraft design and development process. Regulatory documentation, however, remains document-based, making certification a costly component of the design process. This paper reviews three approaches to modeling regulatory documentation of process mapping, ontological modeling, and Unified Modeling Language (UML) and compares their utility in the context of reducing ambiguity, reflecting complexity, and leveraging subject matter expertise. A case study is presented using the advisory circular AC 21.101-1B Establishing the Certification Basis of Changed Aeronautical Products to illustrate the comparison.

Carbon emission reduction accounting method for a CCUS-EOR project

It is difficult to quantify and certify the greenhouse gas (GHG) emission reduction in the entire process of a project of carbon capture, utilization and storage (CCUS)-enhanced oil recovery (EOR). Under the methodological framework for GHG voluntary emission reduction project, the carbon emission reduction accounting method for CCUS-EOR project was established after examining the accounting boundaries in process links, the baseline emission and project emission accounting methods, and the emission and leakage quantification and prediction models, in order to provide a certification basis for the quantification of GHG emission reduction in the CCUS-EOR project. Based on the data of energy consumption, emission and leakage monitoring of the CCUS-EOR industrial demonstration project in Jilin Oilfield, the net emission reduction efficiency is determined to be about 91.1% at the current storage efficiency of 80%. The accounting and prediction of carbon emission reduction for CCUS-EOR projects with different concentrations and scales indicate that within the project accounting boundary, the certified net emission reduction efficiency of the low-concentration gas source CCUS-EOR projects represented by coal-fired power plants is about 37.1%, and the certified net emission reduction efficiency of the high-concentration gas source CCUS-EOR projects represented by natural gas hydrogen production is about 88.9%. The proposed method is applicable to the carbon emission reduction accounting for CCUS-EOR projects under multiple baseline scenarios during the certification period, which can provide decision-making basis for the planning and deployment of CCUS-EOR projects.

Certification considerations for the configuration of a hydrogen-fuelled aeroplane

AbstractReplacing kerosene with hydrogen as a fuel for propelling aeroplanes will undoubtably have ramifications for the existing certification basis and the necessary means of compliance. What this paper attempts to do is explain how a future hydrogen-powered aeroplane could be certified and how this will influence the aircraft’s design. Emphasis has been placed on the safety of hydrogen with regards flammability, ignition energy, cryogenic states and crashworthiness. The influence of certification on a future hydrogen-fuelled aeroplane’s configuration has been established. Lessons learnt from rockets are limited in scope. Consideration of hydrogen’s cryogenic and ambient temperature properties has established some fundamental safety principles. Fuel system crashworthiness influence on certification has been examined. An explosion prevention certification scheme has been developed. It is proposed to exclude oxygen from the fuel system and avoid accumulation of leaked or permeated hydrogen from adjacent zones. Three generic hydrogen-fuelled configurations have been considered for certification: adapting conventional airliner design, hydrogen-electric (fuel cell) propulsion and an unconventional approach. Hydrogen as a safe gas turbine fuel has been examined in technical and environmental terms. Further experimental work to close knowledge gaps in the aviation use of hydrogen has been suggested. In conclusion the necessary changes to the certification basis are outlined. Comments as to what the configuration of a future hydrogen-fuelled aeroplane might look like are provided. These observations are based on analysis of hydrogen’s properties, the existing certification basis, knowledge gaps, and what Special Conditions and Acceptable Means of Compliance might emerge in a future design Type Certification.

Study on Technical Focuses and Sampling Coverage Strategy of Airborne Software Reviews

Airborne software is invisible and intangible, it can have a significant impact on the safety of the aircraft. However, it cannot be exhaustively tested, and can only be assured through a structured, process, activity, and objective-based approach. This paper studied the similarities and differences of software review policies of the four selected National Airworthiness Authorities (NAAs) by using a comparative approach and analysed the general certification basis of specific regulation clauses from the International Civil Aviation Organization Conventions to each contracting States’ regulations by a traceability method. Then analyzed the development processes and objectives applicable to different software levels based on RTCA/DO-178C. Identified 82 technical focus points based on each airborne software development subprocess, then created a Process Technology Coverage matrix to demonstrate the technical focuses of each process. Developed an objective-oriented top-down and bottom-up sampling strategy for the 4 software Stage of Involvement reviews by taking into account the frequency and depth of involvement. Finally, created the Technology Objective Coverage matrix, which can support the reviewers to perform the efficient risk-based SOI reviews by considering the identified technical points, thus to ensure the safety of the aircraft from the software assurance perspective.

EVTOL Certification in FAA and EASA Performance-Based Regulation Environments: A Bird Strike Study-Case

Considering the new generation of air mobility vehicle that has been developed, the electric vertical take-off and landing (eVTOL) aircraft operation will become a reality in the next years. This paper studies the main concerns that can be pointed out due to the different certification approaches that the Federal Aviation Administration (FAA) and European Union Aviation Safety Agency (EASA) have been applying for this kind of aerial vehicle. The paper explores the 14 CFR Part 23-64 and CS-23-5 reorganization to demonstrate how these changes into the requirement structure will be important and influence the eVTOL certification basis construction. Based on the high probability of bird strike events that an eVTOL may face due to its altitude operation, a study-case for a bird strike certification using the known FAA and EASA approaches is performed, considering the current regulation presented into Part 23/CS-23, Part 27/CS-27, Part 29/CS-29 and SC-VTOL-01. The main differences concluded in this evaluation and possible risks and difficulties that an applicant will face during the process are then explored. A final comparison between a bird strike certification process that may be required by FAA and EASA is presented, as well as a recommendation based on the study.

Preliminary Design of GL-1 Sailplane Cockpit Arrangement and Control Mechanism Based on EASA CS-22 Requirements

Sailplaning or gliding is one branch of aero sports activities in Indonesia under Federation of Aero Sport Indonesia (FASI). Until now, the most common sailplane used in Indonesia is still Schweitzer SGS 1-26, which is a single seated metal-fabric sailplane designed in 1955 and produced until 1979. The development of a new national glider to replace the Schweitzer SGS 1-26 had been conducted since 2013 and resulted in a design named GL-1. The EASA CS-22 had been chosen as certification basis for GL-1 as there is no equivalent yet in Indonesian CASR. A preliminary design of internal cockpit arrangement and control mechanism has been conducted. This study shows that the control mechanism using a combination of cable and push-pull rod arrangement satisfy the required control surface movement and limited sailplane interior space.

ОСОБЛИВОСТІ ЗАБЕЗПЕЧЕННЯ АЕРОДИНАМІЧНИХ ХАРАКТЕРИСТИК РЕГІОНАЛЬНОГО ПАСАЖИРСЬКОГО ЛІТАКА

Principal results of the computational and research work performed during development of a regional passenger aircraft to ensure its aerodynamic characteristics are given. When creating the An-148-100/An-158 family of aircraft, such level of the aircraft aerodynamic perfection was achieved, which ensured fulfillment of the specified requirements for their flight performance – maximum speed, cruising flight altitude and flight range with different payloads. The developed aerodynamic configuration made it possible to create a family of regional passenger high-wing planes with a flight speed of up to 870 km/h (true speed) (M = 0.8), which have no analogues in the world aviation industry. Developed for the An-148-100 / An- 158 aircraft, supercritical profiles of the new generation with a large maximum relative thickness formed the basis of the aerodynamic configuration of a high-speed wing with moderate sweep. The aircraft lift-to-drag ratio in cruise flight is Kcruise = 15.8, which corresponds to the worldwide values. Developed aerodynamic configuration of the wing high-lift devices provides high bearing properties of the wing during take-off and landing stages, which allows to fully meet the requirements for the runway required length of the base airfields Lrun = 1485...1950 m. Developed algorithms are implemented in the electric remote control system and provide necessary standard characteristics of stability, controllability and flight dynamics in the main control mode. Selected margins of the aircraft’s own static stability and effectiveness of its controls ensure safe completion of the flight in standby control mode. The certification flight tests of the An-148-100/An-158 airplanes confirmed full compliance of their take-off and landing performance, as well as the stability, controllability and flight dynamics characteristics with the requirements of the Certification basis in both standard and in failure situations tested in flight tests. Necessary and sufficient amount of experimental work was conducted in the lowspeed and high-speed wind tunnels of the ANTONOV SC and TsAGI to verify the aerodynamic and spin characteristics of the An-148-100/An-158 airplane models, which improved the aerodynamic configuration of the aircraft and its individual units and allowed to apply the work results in calculation of aircraft strength, as well as for development of their systems.

Predicting the certification basis for airliner air-to-air refuelling

Abstract The premise is that in the future civil Air-to-Air Refuelling (AAR) will become an economic necessity if popular mass air travel is to continue. What is attempted is to provide a contemporary view of how such future operations could be safely undertaken. The intention is to predict the certification basis for demonstrating safe AAR operation of Cruiser-Feeder concepts. The necessary systems and aircraft functions are treated very much as they are today when civil certifying a large aeroplane type. The compliance demonstration required for environmental conditions, flight envelope, systems providing the necessary functionality, structural integrity, weight and balance are discussed. Applicable existing civil certification requirements are identified and where necessary expanded in scope to accommodate AAR operation. Where contemporary material does not supply appropriate guidance then corresponding safety criteria are proposed to address the deficiency. Lessons learnt from military AAR include the drive for interoperability. This has resulted in extensive efforts to standardise equipment and systems, which are equally applicable to civil AAR. Extremely useful advisory material exists, ranging from flight testing techniques to related safety. The importance of ensuring the consistency of failure condition categorisation at system and aircraft level is highlighted. The treatment of failures when two aircraft are in close proximity is something not considered by civil functional hazard analysis. The concept of AAR as an additional flight phase is introduced and affected system safety analyses identified. Examples of failure conditions that are not catastrophic at system level, but potentially could be at aircraft level during AAR are provided. Rendezvous scenarios are described to illustrate their influence on the certification basis. Combining such considerations with the factors that influence aircraft design leads to ramifications for handling qualities, performance and fuel system design. A viable and certifiable AAR configuration is consequently proposed. Consideration is given to treating operational certification in a progressive manner similar to existing LROPS (Long Range Operations).

Practical Application of Structural Repair Fatigue Life Determination on the AP-3C Orion Platform

The AP-3C Orion aircraft is the oldest aircraft in the Royal Australian Air Force (RAAF) inventory. The planned fleet withdrawal has been extended far beyond the original design service objective. Continued safe and effective operation has required the development of a robust ageing aircraft management approach. A fundamental aspect was supplementing the structural certification basis with appropriate standards in the form of fatigue management requirements from Federal Aviation Regulations (FAR) 25.571 and Federal Aviation Administration Advisory Circular (FAA AC) 120-93. To develop and underpin the ageing aircraft management plan and transition to the supplementary fatigue management standards, the RAAF collaborated with the Original Equipment Manufacturer, Lockheed Martin Aeronautics Company, the United States Navy (USN) and other operators to form the P-3C Service Life Assessment Program (SLAP). This program provided Full Scale Fatigue Test (FSFT) data, associated analyses and analysis tools to support management in accordance with FAR 25.571. An important element of the ageing aircraft management plan included the introduction of a rigorous Safety By Inspection (SBI) maintenance regime to assure structural airworthiness. FAA AC 120-93 requires assessment of structural repairs to determine revised fatigue management and inspection requirements. Often, this information is derived using tailored analysis tools and detailed models on a case-by-case basis. This approach is specialized, expensive and usually occurs after the repair has been designed and installed. To avoid these limitations, the AP-3C Repair Assessment Manual (RAM) was developed to provide the repair designer with a design handbook approach to fatigue analysis. In conjunction with some simple Finite Element (FE) models, the RAM supports complete repair analysis prior to an aircraft leaving the maintenance venue. This paper will present the history of the SBI program, the genesis of the RAM and actual examples of assessing structural repairs on the P-3 platform using the RAM.

건축물 에너지효율등급 인증현황분석을 통한 CO2배출량 평가 베이스라인 연구

The purpose of this study is to establish the assessment baseline of emissions from building operations in the view of GHG reduction policy in Korea. The assessment baseline of emissions shall be used in GHG policy and Carbon Credits in building sectors, but the assessment baseline has not been studied enough or established yet. Also, emissions from building operations will be variable according to the building occupancy. Therefore the baseline will be different and this study aimed at the establishment of the assessment baseline for residential apartments and office buildings firstly. After reviews of BEER and international standards for building emissions such as ISO and UNEP-SBCI documents, the analysis of BEER certification data has been pursued for 292 residential apartment complexes and 65 office buildings in South Korea during 2004~2012. As analysis results, the assessment baseline was set to 23.03 or 1.95 for residential apartment complexes, and 95.91 for office buildings according to the BEER certification basis. Additional assessment baselines were calculated according to year basis, region basis, public and private basis, and GHG policy basis. Finally, the established baseline for residential apartment complexes has been applied for the pilot project in M district, Seoul, and showed 24.97% reduction rate according to the BEER certification basis.

항공기 착륙거리의 여유분 산정에 관한 연구

운항의 여러 단계 중 착륙단계에서 조종사들이 많은 부담을 느낀다. 이는 조종사들이 항공기 속도를 줄이고 접지하여 완전히 정지하는 동안 착륙안전에 영향을 미치는 여러 요소가 있기 때문이다. 만일 착륙하는데 활주로길이가 충분하다면 부담이 적을 수도 있다. 그러나 항상 그런 경우만 있는 것은 아니다. 따라서 착륙성능이 제한범위 내에 있는지 아닌지를 확인할 필요가 있다. 필요착륙거리는 시험비행 조종사에 의해 실증되어진 실제착륙거리에다가 항공사의 평균적인 조종사들을 위한 여유분을 포함한 것이다. FAR의 AFM(항공기 비행규정) 인가는 건조 및 습윤 활주로에서 수동착륙을 기반으로 한다. 기타 다른 활주로 조건에서는 인가가 필요하지 않다. JAR에서는 빙설/윤활활주로에서도 정해진 여유분을 포함시키도록 규정하고 있다. 자동착륙은 인가사항이 아니므로 실제착륙거리만 제공된다. 본 논문에서는 각 활주로 조건에서 포함된 거리 여유분을 분석하고자 한다. 또한 특정한 활주로 조건에서 여유분이 규정되어 있지 않은 경우 대안을 제시하고자 한다. Among the phases of flight operations pilots feel much pressure in landing segment. There is a number of factors affecting landing safety while pilots reduce aircraft speeds and make a touchdown and stop completely. If runway length is sufficient for landing, there maybe is no problem. But it is not the case all the time. So it is necessary to confirm whether landing performance is within limits or not. Required landing distance is actual landing distance demonstrated by flight test pilot plus allowances for average airline pilots. FAR(Federal Aviation Regulations) AFM certification is based upon manual landing for dry and wet runway. Other runway conditions are not the certification basis. JAR dictates even contaminated/slippery runway is included by prescribed allowances. Automatic landing is not certification basis, so actual landing distances are provided. In this paper I would like to analyze distance allowances included in each type of runway condition. In addition there is no regulation about allowances for specific runway condition, I would suggest adequate allowances for that case.

TQM practices in electric fan manufacturing industry of Pakistan

This study aims to descriptively analyse and rank the TQM practices, activities, critical success factors, barriers and business outcomes in electric fan manufacturing industry of Pakistan according to company size and on ISO-9000 certification basis. SMEs of electric fan manufacturing industry of two industrial cities of Gujrat and Gujranwala of Punjab province of Pakistan were selected as unit of analysis and both ISO and non-ISO certified firms were approached. An adopted/bilingual questionnaire was used for data collection using snow ball sampling technique, resulting in 89 completed questionnaires for data analysis. Data was analysed in terms of mean differences among firms both size wise and certification (ISO-9000) wise. The results demonstrate that large sized and ISO-9000 certified firms are more actively involved in TQM practices and activities. However, the small and medium sized firms do not differ significantly in different TQM practices and activities. Top management commitment is considered as the most important success factor by ISO-certified firms while top management training is considered as most important factor by non-certified firms. Lack of resources is the most crucial barrier for both certified and large firms. However, all type of firms consider profit making and decrease in unit cost as desired business outcomes in manufacturing industries. Large companies/ISO-9000 certified companies observed high business outcomes from their counterparts.

Áreas limpas: estudo de correlação entre partículas viáveis e não-viáveis

Este trabalho consiste em um estudo sobre monitoramento ambiental de areas limpas (classes A, B, C e D). Os parâmetros comparados foram particulas nao-viaveis de 0,5 e 5,0 µm e de viaveis em UFC (unidades formadoras de colonias), do ambiente e de superficies (Rodac®). As amostragens nas areas limpas foram feitas em situacoes de repouso e dinâmica, antes e apos sanitizacao, e em etapas de certificacao e rotina. Os dados de literatura indicam que os parâmetros nao sao particularmente dependentes do lay out ou classificacao das areas, mas sim do seu uso e do comportamento dos operadores. As conclusoes foram positivas quanto a correlacao entre diferentes locais de amostragem, para particulas nao viaveis de 0,5 e 5,0 µm, caracterizando-se, porem, ausencia deste tipo de correlacao nas posicoes em fluxo laminar. Tambem, os valores de correlacao foram quase sempre decrescentes com a maior limpeza do ambiente. Os microrganismos mais frequentemente isolados nas areas B, C e D foram Bacillus sp, Staphylococcus sp e Corynebacteriumsp.

Ensuring the continued structural airworthiness of the Airbus A300 commercial transport aircraft

After consideration of the original certification basis of the Airbus A300 commercial transport aircraft, this paper considers typical industry procedures for the justification of the original design service goal, during which the principal structure of the aircraft is reasonably free from significant fatigue cracking. The justification of aircraft life extension, or continued operation beyond design service goal, is then described, including the assessment of fatigue and corrosion damage accumulated during the service life of the aircraft, and the analysis of areas of the structure potentially susceptible to widespread fatigue damage. In addition, the paper discusses the use of preventative maintenance actions to ensure the continued safety of the aircraft during extended service.

A comparison of standards for software engineering based on DO-178B for certification of avionics systems

Certification of avionics software is an increasingly important subject, since more and more avionics systems in future aircraft will be software equipped. The DO-17813 standard provides guidelines for software certification. Re-use of software is emerging, partly enabled by the integrated modular avionics concept, and imposed by a reduction of life-cycle costs. Re-use, however, requires re-certification or certification of software that was not developed according to DO-17813. The DO-178B standard is specially developed to provide a certification basis for avionics software, without going into details of the software development process. Other standards focus on software engineering aspects. We have used the DO-178B standard as a common basis for comparison with DOD-STD2167A (military), ESA PSS-05-0 (space), and IEC65A(Secretariat)122 (industry). Comparison topics include: • • life cycles; • • prescribed documentation; • • configuration management; • • verification and validation; • • quality assurance. All standards prescribe the software development process, emphasizing specific aspects in a certain area of interest. The results of our investigation will assist in understanding the rationale behind several standards, and can be used for: • • certification according to DO-17813 of software that was developed using another standard; • • certification of software using DO-17813, in concert with another standard.

Flight test certification of primary category aircraft using TP101-41E sportplane design standard

This article discusses certification standards, flight testing, and type certification of a primary category aircraft using the Transport Canada TP101-41E Ultra-Light Design Standard as the certification basis. For many years manufacturers maintained that certification standards were overly restrictive with regard to small aircraft of simple design, and therefore, restrict growth and innovation in the small airplane industry. Government agencies in conjunction with industry set forth to design a streamlined certification standard for these type aircraft. The primary category rule for type certification of aircraft of simple design intended for pleasure or personal use was adopted. Presented is an overview of certification and flight test of the Quicksilver GT 500 aircraft that was certified under the primary rule using the Transport Canada TP101-41E Ultra-Light Design Standard. Certification flight test plans and flight test techniques used to gather data are presented. Flight test data and compliance with TP101-41E are discussed. Noncompliant findings are discussed. The Quicksilver GT 500, the first aircraft certified in the primary category, was awarded a provisional-type certificate on August 1, 1993.