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Technical Paper

Wind and Temperature Database for Flight Planning

This paper discusses the importance of enroute wind conditions and the need for a wind measurement system which provides accurate and timely observations of wind and temperature conditions aloft. Recent advances in remote measurement of winds, temperature, and humidity such as the Stratospheric-Tropospheric radars and profilers developed at the National Oceanic and Atmospheric Administration’s Environmental Research Lab form the basis of such a system. A domestic system could and should be established using these devices together with a near real time winds aloft data dissemination network. Estimates of the saving in aircraft fuel consumption benefits range from 1 to 3 percent per year, or from $ 100 to $ 300 million for U.S. aviation system users at current prices and consumption.
Technical Paper

Wind Gusts - 0 - 300 ft Altitude - Homogeneous Terrain

This paper is concerned with the development of statistical models for the gust field in the lowest 300 ft of the atmosphere. It presents some of the highlights of the underlying physics principles, what is known about gusts, and how gusts affect aircraft. The difficulties of developing gust models are accounted for by the lack of data in particular areas and thus direct attention to the work required to provide the needed information.
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Wiley SAE MOBILUS® eBook Package

Committed to being the primary source for aerospace and ground vehicle engineering resources, SAE International has added the full compilation of our Wiley eBook collections to the SAE MOBILUS® technical resource platform. Purchasable as an annual subscription and containing the titles from the Wiley Aerospace Collection, the Wiley Automotive Collection, the Wiley Computer Systems Collection, and the Wiley Cyber Security Collection.
SAE MOBILUS Subscription

Wiley Aerospace Collection

Purchasable as an annual subscription and containing 30 eBook titles, the Wiley Aerospace Collection covers valuable engineering subject matter, such as aircraft fuel systems, aerodynamics, and propulsion. The series also goes beyond engineering, including eBooks on planning, logistical issues, and how human behavior can be managed and controlled while operating aircraft.

White Paper to Support Supersession of MIL-S-8879C With AS8879C

This paper was prepared to support supersession of MIL-S-8879C with Screw Thread Conformity Task Force selected industry standard AS8879C, published by the Society of Automotive Engineers (SAE). Other documentation changes will be covered by separate papers. Separate papers are anticipated for thread gaging issues, and thread gage calibration procedures. The STC-TF decided that the thread design standard needed to be completed before thread gage definition could be addressed. Thread gage definition has to be known before calibration procedures can be addressed.
Technical Paper

Weight Optimization of Fork and Axle of Main Landing Gear for an Unmanned Aerial Vehicle by Finite Element Analysis

Unmanned Aerial Vehicles (UAV) are being deployed in military, law enforcement, search & rescue, scientific research, environmental & climate studies, reconnaissance and other commercial and non-commercial applications on a large scale. A design and development of landing gear system has been taken up for a UAV. This paper presents the design optimization of structural components of Wheel-Brake & Fork assembly pertaining to the Main Landing Gear (MLG) for a UAV. The wheel, fork, axle and brake unit constitute the wheel assembly. The wheel-brake assembly is assembled with the strut assembly and forms the Landing gear system. The Fork is the connecting member between the shock strut and the axle containing the wheel-brake assembly. As the fork and axle are subjected to shock loads while landing, the strength of these components are very much essential to withstand the dynamic loads.
Technical Paper

Weibull/Weibayes Analysis of Hydraulic Pump Malfunction Data

Premature wearout of augmentor hydraulic fuel pumps was being experienced in service on a fighter aircraft engine. The removal times ranged from 150 to 800 engine operating hours. Considerable effort had gone into the understanding of the physics of failure and overcoming this problem in a modified pump. However, there still remained the question of how best to proof test the new pump. The challenge was to demonstrate that the redesigned pump was significantly better than the old pump. The problems faced during design verification will be discussed in this case study. For example, does an accelerated test duplicate the service failure mode? When has an accelerated test run long enough to prove the redesign is in fact better than the old product? This paper illustrates the application of new technology to solve these research and development program problems through the use of Weibull and Weibayes Analysis.
Training / Education

Weibull-Log Normal Analysis Workshop

RMS (Reliability-Maintainability-Safety-Supportability) engineering is emerging as the newest discipline in product development due to new credible, accurate, quantitative methods. Weibull Analysis is foremost among these new tools. New and advanced Weibull techniques are a significant improvement over the original Weibull approach. This workshop, originally developed by Dr. Bob Abernethy, presents special methods developed for these data problems, such as Weibayes, with actual case studies in addition to the latest techniques in SuperSMITH® Weibull for risk forecasts with renewal and optimal component replacement.

Water Spray and High Humidity Endurance Test Methods for SAE AMS1424 and SAE AMS1428 Aircraft Deicing/Anti-icing Fluids

This document establishes the minimum requirements for an environmental test chamber, and test procedures to carry out anti-icing performance tests according to the current materials specification for aircraft deicing/anti-icing fluids. The primary purpose for such a test method is to determine the anti-icing endurance under controlled laboratory conditions of AMS1424 Type I and AMS1428 Type II, III, and IV.
Journal Article

Visualization of Oxidation of Soot Nanoparticles Trapped on a Diesel Particulate Membrane Filter

Through microscopic visualization experiments, a process generally known as depth filtration was shown to be caused by surface pores. Moreover, the existence of a soot cake layer was an important advantage for filtration performance because it could trap most of the particulates. We proposed an ideal diesel particulate filter (DPF), in which a silicon carbide (SiC) nanoparticle membrane (made from a mixture of 80 nm and 500 nm powders) instead of a soot cake was sintered on the DPF wall surface; this improved the filtration performance at the beginning of the trapping process and reduced energy consumption during the regeneration process. The proposed filter was called a diesel particulate membrane filter (DPMF). A diesel fuel lamp was used in the trapping process to verify the trapping and oxidation mechanisms of ultrafine particulate matter. Thus, the filtration performance of the membrane filters was shown to be better than that of conventional DPFs.
Technical Paper

Vibratory Strain Distribution in an Integral-Machined Air Turbine Starter Wheel

Turbine blade fatigue failures began to occur on the Garrett Air Turbine Starter, Model ATS200-58, in commercial airline service. A comprehensive program including metallurgical analysis, finite-element analysis, and strain gage testing of instrumented turbine wheels resulted in large quantities of data on blade vibratory strain. The results of testing various configurations, including the addition of damping and the use of different numbers of stator vanes, are presented.
Technical Paper

Vibration of Instrument-Boards and Airplane Structures

THIS paper supplements one on the same subject by the same author, published in October, 1931, and describes a new and improved three-component vibrograph with which separate vibrograms of the three components can be obtained simultaneously and with considerable magnification. A short mathematical analysis is given to show the fundamental difference between vibrographs and accelerometers. Effects of vibration on different instruments are discussed and the approximate maximum permissible amplitude of vibration at cruising-speed frequency for various instruments is presented in a table. Consideration is given to correct design of instrument-boards and their suspension in an airplane, and the theory of forced vibration with damping is reviewed to show that, if not rightly chosen, shock-absorbing materials can do as much harm as good.
Training / Education

Vibration Analysis Using Finite Element Analysis (FEA) Web Seminar RePlay

Finite Element Analysis (FEA) has been used by engineers as a design tool in new product development since the early 1990's. Until recently, most FEA applications have been limited to static analysis due to the cost and complexity of advanced types of analyses. Progress in the commercial FEA software and in computing hardware has now made it practical to use advanced types as an everyday design tool of design engineers. In addition, competitive pressures and quality requirements demand a more in-depth understanding of product behavior under real life loading conditions.
Training / Education

Vibration Analysis Using Finite Element Analysis (FEA)

Finite Element Analysis (FEA) has been used by engineers as a design tool in new product development since the early 1990's. Until recently, most FEA applications have been limited to static analysis due to the cost and complexity of advanced types of analyses. Progress in the commercial FEA software and in computing hardware has now made it practical to use advanced types as an everyday design tool of design engineers. In addition, competitive pressures and quality requirements demand a more in-depth understanding of product behavior under real life loading conditions.
Technical Paper

Very High Frequency Monitoring System for Engine Gearbox and Generator Health Management

In cooperation with the major propulsion engine manufacturers, the authors are developing and demonstrating a unique very high frequency (VHF) vibration monitoring system that integrates various vibro-acoustic data with intelligent feature extraction and fault isolation algorithms to effectively assess engine gearbox and generator health. The system is capable of reporting on the early detection and progression of faults by utilizing piezoelectric, optical, and acoustic frequency measurements for improved, incipient anomaly detection. These gas turbine engine vibration monitoring technologies will address existing operation and maintenance goals for current military system and prognostics health management algorithms for advanced engines.
Technical Paper

Verification of Supply Chain Quality for Perishable Tools

Increased emphasis on standardizing processes and controlling variability in production operations includes validating perishable tools used in daily operations. Even though dealing with reputable manufacturers, many factors including communication, custom specifications and personnel turnover can lead to the perpetuation of mistakes if errors are not discovered and corrective action implemented. However, inspection is costly and inspection costs far outweigh many item costs unless considering product defects. A beneficial balance may be obtained by employing statistical sampling techniques similar to ISO 2859 [1] to verify the quality of incoming tools.