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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 127 records · Page 7

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NASA NTRS1973

Takeoff certification considerations for large subsonic and supersonic transport airplanes using the Ames flight simulator for advanced aircraft

Data for use in development of takeoff airworthiness standards for new aircraft designs such as the supersonic transport (SST) and the large wide-body subsonic jet transport are provided. An advanced motion simulator was used to compare the performance and handling characteristics of three representative large jet transports during specific flight certification tasks. Existing regulatory constraints and methods for determining rotation speed were reviewed, and the effects on takeoff performance of variations in rotation speed, pitch attitude, and pitch attitude rate during the rotation maneuver were analyzed. A limited quantity of refused takeoff information was obtained. The aerodynamics, wing loading, and thrust-to-weight ratio of the subject SST resulted in takeoff speeds limited by climb (rather than lift-off) considerations. Take-off speeds based on U.S. subsonic transport requirements were found unacceptable because of the criticality of rotation-abuse effects on one-engine-inoperative climb performance. Adequate safety margin was provided by takeoff speeds based on proposed Anglo-French supersonic transport (TSS) criteria, with the limiting criterion being that takeoff safety speed be at least 1.15 times the one-engine-inoperative zero-rate-of-climb speed. Various observations related to SST certification are presented.

Snyder, C. T.↗

NASA NTRS1978

Certification and verification for Calmac flat plate solar collector

Information used in the certification and verification of the Calmac Flat Plate Collector is presented. Contained are such items as test procedures and results, information on materials used, installation, operation, and maintenance manuals, and other information pertaining to the verification and certification.

Source record↗

NASA NTRS1983

Cleanroom certification model

The Cleanroom software development methodology is designed to take the gamble out of product releases for both suppliers and receivers of the software. The ingredients of this procedure are a life cycle of executable product increments, representative statistical testing, and a standard estimate of the MTTF (Mean Time To Failure) of the product at the time of its release. A statistical approach to software product testing using randomly selected samples of test cases is considered. A statistical model is defined for the certification process which uses the timing data recorded during test. A reasonableness argument for this model is provided that uses previously published data on software product execution. Also included is a derivation of the certification model estimators and a comparison of the proposed least squares technique with the more commonly used maximum likelihood estimators.

Currit, P. A.↗

NASA NTRS1984

Certification of advanced systems

Advanced cockpit systems in helicopters are evaluated in terms of safety certification areas of concern include: (1) power supply system, failure analysis; (2) software control; (3) lightning substantiation; and (4) adequacy of certification regulations.

Swihart, J. D., Jr.↗

NASA NTRS1988

Tape-Certification Program

TAPECERT is VAX utility program for tape certification. Allows user to select tape density, test pattern to use, and number of allowed retries, and to decide whether to allow extended inter-record gaps to skip past bad spots on tape. Displays system error messages and record-count information with totals every 1,000 blocks. Designed so command procedure set up with defaults for different types of certification runs. Written in FORTRAN 77.

Fullner, Scott E.↗

NASA NTRS1988

Zero/zero rotorcraft certification issues. Volume 2: Plenary session presentations

This report analyzes the Zero/Zero Rotorcraft Certification Issues from the perspectives of manufacturers, operators, researchers and the FAA. The basic premise behind this analysis is that zero/zero, or at least extremely low visibility, rotorcraft operations are feasible today from both a technological and an operational standpoint. The questions and issues that need to be resolved are: What certification requirements do we need to ensure safety. Can we develop procedures which capitalize on the performance and maneuvering capabilities unique to rotorcraft. Will extremely low visibility operations be economically feasible. This is Volume 2 of three. It presents the operator perspectives (system needs), applicable technology and zero/zero concepts developed in the first 12 months of research of this project.

Adams, Richard J.↗

NASA NTRS1988

Zero/zero rotorcraft certification issues. Volume 3: Working group results

This report analyzes the Zero/Zero Rotorcraft Certification Issues from the perspectives of manufacturers, operators, researchers and the FAA. The basic premise behind this analysis is that zero/zero, or at least extremely low visibility, rotorcraft operations are feasible today from both a technological and an operational standpoint. The questions and issues that need to be resolved are: What certification requirements do we need to ensure safety. Can we develop procedures which capitalize on the performance and maneuvering capabilities unique to rotorcraft. Will extremely low visibility operations be economically feasible. This is Volume 3 of three. It provides the issue-by-issue deliberations of the experts involved in the Working Groups assigned to deal with them in the Issues Forum.

Adams, Richard J.↗

NASA NTRS1990

Flight test investigation of certification issues pertaining to general-aviation-type aircraft with natural laminar flow

Development of Natural Laminar Flow (NLF) technology for application to general aviation-type aircraft has raised some question as to the adequacy of FAR Part 23 for certification of aircraft with significant NLF. A series of flight tests were conducted with a modified Cessna T210R to allow quantitative comparison of the aircraft's ability to meet certification requirements with significant NLF and with boundary layer transition fixed near the leading edge. There were no significant differences between the two conditions except an increasing in drag, which resulted in longer takeoff distances and reduced climb performance.

Doty, Wayne A.↗

NASA NTRS1990

A flight test investigation of certification requirements for laminar-flow general aviation airplanes

A modified T210R general aviation aircraft incorporating natural laminar flow (NLF) technology has been subjected to flight tests in order to evaluate its stability and control characteristics. Attention is given to this aircraft's ability to meet certification requirements with significant NLF, as well as with the boundary-layer transition fixed near the leading edge. It is established that the large regions of NLF achieved yielded a significant cruise performance enhancement; loss of laminar flow did not result in significant changes in the stability and control characteristics of the aircraft. FAR Part 23 certification requirements were met.

Manuel, Gregory S.↗

NASA NTRS1990

Space shuttle redesigned solid rocket motor Certificate of Qualification (COQ) data report

The Space Shuttle Redesigned Solid Rocket Motor (RSRM) Certification Program provides confidence that the RSRM and its components/subsystems meet or exceed Mission Oriented Requirements when manufactured per design requirements and specified/approved processes. Certification is based on documented results of tests, analyses, inspections, similarity, and demonstrations. Evidencing information is provided to certify that each RSRM component/subsystem satisfies design, mission related requirements and objectives.

Duersch, Fred, Jr.↗

NASA NTRS1991

Liquid rocket engine flight certification

The following subject areas are covered: current rocket engine certification process; certification issues; engine characteristics; engine design and mission requirements; structural design criteria; structural design factors of safety; component/subsystem testing; system level development tests; certification/qualification tests; observations; and proposed actions/programs.

Richards, Steve↗

NASA NTRS1991

Certification of lightning protection for a full-authority digital engine control

FADEC systems present many challenges to the lightning protection engineer. Verification of the protection-design adequacy for certification purposes presents additional challenges. The basic requirements of the certification plan of a FADEC is to demonstrate compliance with Federal Airworthiness Regulations (FAR) 25.1309 and 25.581. These FARs are intended for transport aircraft, but there are equivalent sections for general aviation aircraft, normal and transport rotorcraft. Military aircraft may have additional requirements. The criteria for demonstration of adequate lightning protection for a FADEC systems include the procedures outlined in FAA Advisory Circular (AC) 20-136, Protection of aircraft electrical/electronic systems against the indirect effects of lightning. As FADEC systems, including the interconnecting wiring, are generally not susceptible to direct attachment of lightning currents, the verification of protection against indirect effects is primarily described.

Dargi, M.↗

NASA NTRS1991

Revision of certification standards for aviation maintenance personnel

Part 65, Subparts D and E, of the Federal Aviation Regulations (FAR) identify the certification requirements for aviation mechanics and aviation repairmen. The training, experience, privileges, ratings, recordkeeping, and currency requirements for aviation maintenance personnel are also addressed by these parts of the FAR. The recent emergence of the aging fleet problem and the introduction of new technologies, aircraft, engines, and aeronautical products has caused certain portions of these rules to become obsolete. Further, international political arrangements, such as bilateral airworthiness and maintenance agreements, International Civil Aviation Organization (ICAO) standards, certain international agreements for maintenance personnel training, and mechanic certificate reciprocity, have all impacted on the current regulatory policy.

Aging Aircraft↗

NASA NTRS1990

Damage tolerance certification methodology for composite structures

An advanced certification methodology was developed for composite structures to include the effects of impact damage. The methodology has the capability to determine the reliability of impact damaged structure at any prescribed load level and impact threat, which may be specified in terms of impact energy or C-scan damage area. In addition, the methodology can also calculate the allowable impact threat level at a given applied load and specified reliability. The developed damage tolerance certification methodology was demonstrated on the F/A-18 inner wing. The results of the methodology demonstration showed that the F/A-18 inner wing has excellent damage tolerance capability.

Kan, Han Pin↗

NASA NTRS1990

Certification of damage tolerant composite structure

A reliability based certification testing methodology for impact damage tolerant composite structure was developed. Cocured, adhesively bonded, and impact damaged composite static strength and fatigue life data were statistically analyzed to determine the influence of test parameters on the data scatter. The impact damage resistance and damage tolerance of various structural configurations were characterized through the analysis of an industry wide database of impact test results. Realistic impact damage certification requirements were proposed based on actual fleet aircraft data. The capabilities of available impact damage analysis methods were determined through correlation with experimental data. Probabilistic methods were developed to estimate the reliability of impact damaged composite structures.

Rapoff, Andrew J.↗

NASA NTRS1993

Space assembled entry systems certification

The approach taken to the issue, that 'How do you say you're 'good for go' if you space assemble an entry vehicle?', are: (1) shuttle orbiter thermal protection certification; (2) shuttle thermal protection system flight experience; and (3) space assembled entry system certification.

Curry, Donald M.↗

NASA NTRS1993

Development of a proposed international standard for certification of aircraft to High Intensity Radiated Fields (HIRF)

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 both the technical challenge of drafting a certification procedure and guidance standard as well as 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.

Sargent, Noel B.↗

NASA NTRS1993

Windshear Database for Forward-Looking Systems Certification

This document contains a description of a comprehensive database that is to be used for certification testing of airborne forward-look windshear detection systems. The database was developed by NASA Langley Research Center, at the request of the Federal Aviation Administration (FAA), to support the industry initiative to certify and produce forward-look windshear detection equipment. The database contains high resolution, three dimensional fields for meteorological variables that may be sensed by forward-looking systems. The database is made up of seven case studies which have been generated by the Terminal Area Simulation System, a state-of-the-art numerical system for the realistic modeling of windshear phenomena. The selected cases represent a wide spectrum of windshear events. General descriptions and figures from each of the case studies are included, as well as equations for F-factor, radar-reflectivity factor, and rainfall rate. The document also describes scenarios and paths through the data sets, jointly developed by NASA and the FAA, to meet FAA certification testing objectives. Instructions for reading and verifying the data from tape are included.

Switzer, G. F.↗