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Video

Fault-Tree Generation for Embedded Software Implementing Dual-Path Checking

2011-11-17
Given the fast changing market demands, the growing complexity of features, the shorter time to market, and the design/development constraints, the need for efficient and effective verification and validation methods are becoming critical for vehicle manufacturers and suppliers. One such example is fault-tree analysis. While fault-tree analysis is an important hazard analysis/verification activity, the current process of translating design details (e.g., system level and software level) is manual. Current experience indicates that fault tree analysis involves both creative deductive thinking and more mechanical steps, which typically involve instantiating gates and events in fault trees following fixed patterns. Specifically for software fault tree analysis, a number of the development steps typically involve instantiating fixed patterns of gates and events based upon the structure of the code. In this work, we investigate a methodology to translate software programs to fault trees.
Video

The Correlation of As-Manufactured Products to As-Designed Specifications: Closing the Loop on Dimensional Quality Results to Engineering Predictions

2012-03-09
Simulation-based tolerance analysis is the accepted standard for dimensional engineering in aerospace today. Sophisticated 3D model-based tolerance analysis processes enable engineers to measure variation in complex, often large, assembled products quickly and accurately. Best-in-class manufacturers have adopted Quality Intelligence Management tools for collecting and consolidating this measurement data. Their goal is to completely understand dimensional fit characteristics and quality status before commencing the build process. This results in shorter launch cycles, improved process capabilities, reduced scrap and less production downtime. This paper describes how to use simulation-based approaches to correlate the theoretical tolerance analysis results produced during engineering simulations to actual as-built results. This allows engineers to validate or adjust as-designed simulation parameters to more closely align to production process capabilities.
Video

Visionary's Take: An Engineering Journey into the Marketplace (Part 3 of 3)

2017-10-12
Can you become a visionary or are you born one? How does a visionary capture an opportunity and makes it a successful business? Are engineers more qualified to solve technical problems or run companies? SAE's "The Visionary's Take" addresses these and many other questions, by talking directly with those who have dared to tackle difficult engineering problems, and create real-life products out of their experience. In these short episodes, Sanjiv Singh and Lyle Chamberlain, respectively CEO and Chief Engineer from Near Earth Autonomy, talk about their experience in creating a brand-new company in the UAV world. Founded in 2011, Near Earth Autonomy brought together a group of engineers and roboticists, looking for unconventional solutions to very hard logistics problems, presenting danger to human life. The answers were developed by pushing technology to a higher level, testing quickly and often, and keeping an open mind to alternative ways of framing engineering challenges.
Video

Visionary's Take: An Engineering Journey into the Marketplace (Part 1 of 3)

2017-10-12
Can you become a visionary or are you born one? How does a visionary capture an opportunity and makes it a successful business? Are engineers more qualified to solve technical problems or run companies? SAE's "The Visionary's Take" addresses these and many other questions, by talking directly with those who have dared to tackle difficult engineering problems, and create real-life products out of their experience. In these short episodes, Sanjiv Singh and Lyle Chamberlain, respectively CEO and Chief Engineer from Near Earth Autonomy, talk about their experience in creating a brand-new company in the UAV world. Founded in 2011, Near Earth Autonomy brought together a group of engineers and roboticists, looking for unconventional solutions to very hard logistics problems, presenting danger to human life. The answers were developed by pushing technology to a higher level, testing quickly and often, and keeping an open mind to alternative ways of framing engineering challenges.
Video

A New Policy for COTS Selection: Overcome the DSM Reliability Challenge

2012-03-13
Up to now, the reliability achieved by COTS components was largely sufficient for avionics, in terms of failure rate as well as time to failure. With the implementation of new and more integrated technologies (90 nm node, 65 nm and below), the question has arisen of the impact of the new technologies on reliability. It has been stated that the lifetime of these new technologies might decrease. The drift is expected to be technology dependent: integration, technology node, materials, elementary structure choices and process pay a key role. Figures have been published, which gives smaller lifetime than the 30 years generally required for avionics. This would of course impact not only the reliability, but also the maintenance of COTS-based avionics. Hence a new policy should be defined for the whole COTS supply chain. Faced with these impending risks, different methodologies have been developed.
Standard

Counterfeit Materiel; Assuring Acquisition of Authentic and Conforming Materiel - Bearings

2020-04-21
WIP
AS6834
This document standardizes requirements for bearings: (a) supply chain management, procurement, inspection, parts management, and test/evaluation to assure the authenticity of bearings being acquired/used, and (b) response strategies when suspect or confirmed counterfeit bearings are discovered. Though developed primarily for critical application bearings, the document also may be applicable, at the discretion of the user, to other bearings with similar characteristics and applications. The bearings slash sheet is not intended to replace, conflict with, or duplicate requirements in quality system or AMS series material specs but rather to augment them with regards to counterfeit prevention and risk mitigation.
Technical Paper

Aircraft Propellers

1929-01-01
290059
NEARLY all the aircraft propellers used by both the Army and the Navy are of the detachable-blade type. The Navy has found it necessary to make its own designs and to furnish the propeller manufacturers with finished detail drawings. The author lists the sources from which data can be obtained and shows a chart from which can be found a diameter and setting of a pair of detachable blades that will give reasonably good performance for nearly any horsepower, revolutions per minute and airspeed commonly used with the direct-drive type of propeller. Discrepancies between model tests and wind-tunnel tests are cited, and the author then considers the subject theoretically. Substitute propellers are next considered, and also the strength of propellers.
Technical Paper

Airplane Lighting Requirements

1929-01-01
290067
INCREASE in the amount of night flying with the advent of airplanes into the commercial field makes more acute the need for proper lighting facilities, not only of airports and airways, but of the airplanes themselves. As only about one-half of the regularly used airways in this Country are lighted for night flying, and few airports are equipped with lighting facilities for night landings, it is necessary for airplanes to be provided with lighting equipment for flying and for emergency landing at night. Besides the high-intensity lighting needed for following unlighted airways and for landing, airplanes need navigation lights and illumination for the instruments and the cabin. Immediate study and direction should be given to the problems of meeting each of these requirements most effectively and economically before it becomes too difficult to standardize methods and equipment.
Technical Paper

Air-Transport Maintenance Problems from the Service Viewpoint

1932-01-01
320062
VIEWS of the maintenance chiefs of all major air-transport lines, based upon their experiences in this field and as transmitted by them through the Maintenance Committee of the Aeronautical Chamber of Commerce of America, Inc., are embodied in the paper. Representing as it does the collective experience of the best minds in the field, the paper is particularly significant and worthy of the consideration of manufacturers, engineers and others directly concerned with the problems presented. As to fuselage and wing coverings, it is stated that fabric has a definite advantage when considering weight and emergency repairs. Airplanes covered with fabric can be restored to service quickly in cases where, with the same damage, replacement of other forms of covering would cause the plane to be laid up in the shop at a time when it is most needed. With the new improved finishes, fabric is said to be as satisfactory as any covering available.
Technical Paper

Aircraft-Engine Installation

1930-01-01
300037
THE PAPER urges united cooperation instead of the present division of responsibility between the engine designer and the airplane designer in the installation of aircraft engines. The tubular rings upon which engines are commonly mounted are usually supported by structural members that are welded to the ring and attached to the fuselage at the four longitudinals. Inaccuracy is common in these structures, and many of them lack sufficient stiffness. Gravity gasoline-feed is recommended for its simplicity, provided the pressure head required by the carbureter can be secured, but the author reports having seen an installation in which the engine would operate so long as the airplane had its tail on the ground, yet the engine would die as soon as the tail was raised during a take-off. The use of gasoline-resisting rubber-hose with metal liners and the avoidance of sharp bends are recommended for the gasoline connections.
Technical Paper

The Operator's Airplane and Engine Requirements

1930-01-01
300032
CAUSES of troubles and expense to air-transport companies in their airplanes are dealt with comprehensively by the operations manager and a division superintendent of the National Air Transport. Commercial operation is asserted to be the proving ground for the products of both airplane and airplane-engine manufacturers, and four reasons given for this are (a) lack of understanding between the manufacturer and the purchaser as to precisely what is required of the airplane purchased, (b) inability of the manufacturer to deliver a product equal to his anticipation, (c) inability of the operator properly to use and care for the equipment furnished, and (d) the varied and opposed uses to which different operators must put their equipment. Detailed and valuable information is given regarding the parts that give trouble and what should be done to avoid it.
Technical Paper

Increasing the Thrust Horsepower from Radial Air-Cooled Engines

1931-01-01
310037
MANUFACTURERS of radial air-cooled engines have centered their attention upon low specific weight for their product. This is accomplished by compact design, using the best of materials and the highest grade of workmanship and finish, with the production of the maximum possible horsepower per cubic inch of engine displacement. High output can be accomplished by a combination of high rotative speed and high brake mean effective pressure with low friction losses. Many considerations of design and operation must be correctly proportioned to approach the ultimate in horsepower. Important advances have been made in improving engine output by cooling air-cooled cylinders with well designed fins supplied with air from directing baffles, thus increasing the brake mean effective pressure which can be produced on a given fuel without detonation.
Technical Paper

Developments in Lighter-than-Air Craft

1929-01-01
290053
NOTABLE developments in 1928 that have greatly increased interest in lighter-than-air craft were the transatlantic flight of the Graf Zeppelin as an experiment in commercial transoceanic air-service, the ordering by the United States Navy Department of the construction in this Country of two rigid airships larger than any yet built or under construction, the development and construction of two British airships for long-distance passenger and mail transportation, the starting of erection of the world's largest airship factory and dock at Akron, Ohio, and the construction and operation in this Country of a number of non-rigid airships to be used for commercial purposes. Each of these developments is dealt with in order. General dimensions, major characteristics, and unique features of the Graf Zeppelin, the new Navy airships, and the projected large transoceanic commercial airships are given.
Technical Paper

Aviation Fuels-What the Airlines WANT and EXPECT

1946-01-01
460203
WITHIN 10 years, Mr. Brower predicts, airlines will use over 1,000,000,000 gal of fuel annually, consequently, what the airlines want and expect in the way of aviation fuels is of major importance. The author stresses particularly that airlines would like less talk of so-called “super fuels,” especially at premium prices, and more interest in down-to-earth, realistic development of economical and safe fuels of good quality. After presenting a resumé of the grades of fuel that he expects will be required in the future. Mr. Brower expresses the thought that to obtain these results, the cooperation that has developed between the fuel refiner, the engine and airframe manufacturers, and the air transport operators must be maintained.
Technical Paper

REVIEW OF AIR TRANSPORT DEVELOPMENTS IN AMERICA

1946-01-01
460249
DURING 1945 many new ideas and developments started to be put in practice in the civil air transport industry. A large portion of these, along such lines as automatic flight control, emergency equipment, airport design, and instrument landing development, came from the vast experimental work carried on by the military during the war. Mr. Kelly in this paper summarizes and reviews the important points in the papers sponsored by the SAE Air Transport Activity during 1945. He mentions that the airlines are increasing their engineering staffs and he believes that these staffs should cooperate to the fullest extent in the future with the manufacturers. He stresses the need for adequate training programs in the airline industry. He tells the new problems that are present in the industry today and some possible solutions to them. This is a comprehensive paper of the progress made in the air transport industry.
Technical Paper

Factors Relative to Selected STALLING-SPEED REGULATIONS FOR TRANSPORT AIRPLANES

1946-01-01
460250
MR. VANIK discusses the limiting effect of maximum stalling-speed requirements on efficient design of high-speed transport airplanes and shows that deletion of this requirement would result in no difficult operational problems. He also shows that retention of fixed stalling-speed requirements will result in placing American manufacturers and operators at a serious disadvantage in the international field.
Technical Paper

Cushion Design From Fragility Rating

1956-01-01
560023
GENERAL problems which arise in packaging design are treated, including a discussion of cushioning characteristics, fragility rating, and the energy concept of static and dynamic testing of cushion material. A nomogram is presented which can be of use in designing cushioning installations. The author suggests the following: 1. For maximum vibration protection, the natural frequency of the cushioned package should be at least one-third of the lowest critical-component natural frequency in the equipment shipped. 2. For necessary protection of equipment such as guided missiles, all-metal mounting systems of nonlinear design combined with a damping ratio of 20% should be employed.
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