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White Paper

REDUCING DOWNTIME THROUGH THE USE OF PREDICTIVE ANALYTICS AND TECHNICAL TRAINING ADVANCEMENTS

2018-01-05
WP-0007
The exponential increase in the number of aircraft and air travelers has triggered new innovations aimed to make airline services more reliable and consumer friendly. Quick and efficient maintenance actions with minimum downtime are the need of the hour. Another major challenge is ensuring maintenance personnel are trained effectively; technology like augmented reality and Virtual Maintenance Trainers (VMTs) may provide safe and efficient training in lieu of live, instructor-led arrangements. And while traditional User/Maintenance Manuals provide useful information when dealing with simple machines, when dealing with complex systems of systems and miniaturized technologies, like unmanned aerial vehicles (UAVs), new technologies like augmented reality can rapidly and effectively support the maintenance operations.
White Paper

Innovative Assembly Systems for the Aerospace Industry

2017-10-31
WP-0004
The aerospace industry is facing new challenges to meet burgeoning customer demand. An unprecedented number of orders for commercial aircraft is forcing aerospace manufacturing to make gains in efficiency throughout aircraft production and operation. However, current manufacturing systems are using technologies and production methods unsuited to a future dynamic market. To ensure its profitability, the aerospace industry must seize the opportunity to innovate and readdress approaches to manufacturing. This whitepaper looks at four advanced manufacturing (AM) solutions designed to improve assembly process efficiency, automation, and accuracy.
Tech Insights

Balance of Plant: Integrating PEM Fuel Cells into Aircraft

2017-11-13
TI-0002
While all-electric aircraft remain at the bleeding edge of the aviation industry, incorporating technologies like proton exchange membrane fuel cells into existing aircraft can result in considerable auxiliary capability with low environmental impact. However, proper consideration must be given to supporting systems to achieve a reliable balance of plant-especially when those systems interface with existing aircraft architectures. The scope of the BoP is to manage and condition the reactant flows to and from the fuel-cell module and to provide power to system components.
White Paper

Electric Flight Technology

2017-10-25
WP-0002
The environmental impact of hydrocarbon-burning aircraft, both from the perspective of gas emissions and that of noise, is one of the main motivations for the move to electric propulsion. The added benefit from this shift to electric propulsion is that it has resulted in lowering the costs of electrical components such as motors, power electronic (PE) circuits, and batteries that are essential to this technology. This white paper seeks to explore the history, architecture, electrical components, and future trends of electric flight technology.
Tech Insights

Repairing Composites

2017-08-09
TI-0001
As the aerospace industry continues on its quest for ever-increased efficiency, so goes the quest for ever-more composite content on aircraft. And with it, more opportunities to repair it. Typical composite panel fiber reinforcements are carbon, aramid, and fiberglass. The machining techniques for these typical composite materials are similar, but minor differences exist, such as the style of cutting tool or drill bit. Automated drilling methods that may be used during original manufacture are rarely used in typical composite repair situations.
Technical Paper

Subjective and Objective Assessment Of Vehicle Handling Performance

2000-06-12
2000-05-0247
The results of a research programme involving a three pronged approach to vehicle handling - involving a series of experimental measurements, subjective assessments and modelling predictions (1) - were presented at FISITA 98 in Paris. From the analysis of this extensive range of results it was concluded that although some significant areas of correlation e.g. transient step steer responses, were identified, there was still some way to go before the confidence levels such as those associated with aircraft practice could be achieved. Consequently, a subset of the results - in particular those associated with the results frequency response measurements - have been analysed using a technique proposed originally in 1990 at Mitsubishi (2). This approach is called the “Four Parameter Evaluation Method” and uses a rhombus pattern graph to plot out steady state yaw velocity gain, natural frequency of yaw velocity, damping of yaw velocity response and phase delay at 1 Hz lateral acceleration.
Technical Paper

SOME FACTORS OF ENGINE PERFORMANCE

1920-01-01
200042
A large number of tests were made in the altitude laboratory of the Bureau of Standards, using aircraft engines. The complete analysis of these tests was conducted under the direction of the Powerplants Committee of the National Advisory Committee for Aeronautics. Many of the engines were of the same make, differing in compression ratio or dimensions. The testing program included determinations of the brake-horsepower at various speeds and altitudes, or air densities, and the friction power, or the power required to operate the engine with no fuel or ignition at various speeds and air densities, with normal operating conditions of oil, water and the like. Some tests included determination of the effect of change of mixture ratio and of air temperature, and of different oils. The difficulties caused by the necessity of using indirect methods to ascertain the effect of various factors are outlined. The test analyses and curves are presented.
Technical Paper

ENGINE SHAPE AS AFFECTING AIRPLANE OPERATION

1920-01-01
200025
The annual report covering transportation by the largest British air-transport company laid particular emphasis upon the greater value of the faster machines in its service. Granted that efficient loads can be carried, the expense, trouble and danger of the airplane are justified only when a load is carried at far greater speed than by any other means. A reasonable conclusion seems to be that we can judge the progress made in aviation largely by the increased speed attainable. It is interesting and possibly very valuable therefore to inquire into the relations of power and resistance as applied to small racing machines with aircraft engines that are available.
Technical Paper

THE HEAT-TREATING OF BRAZED FITTINGS FOR AIRCRAFT

1920-01-01
200022
A tendency exists in most shops to assume that brazed joints cannot be successfully heat-treated. As a consequence, many fittings used in aircraft work and assembled by brazing smaller parts together are finished and installed without being heat-treated after the brazing operation. This practice causes parts to be used that not only do not develop the available strength of the material, but which are in some cases, under internal stress due to the heating in the brazing operation. Recent experiments made at the Naval Aircraft Factory show that the assumption mentioned is entirely erroneous. The author considers this matter with a view to specifying the use of steels and brazing spelters which will permit the subsequent or perhaps the simultaneous heat-treatment of the parts.
Technical Paper

Advanced Aerodynamic Devices to Improve the Performance, Economics, Handling and Safety of Heavy Vehicles

2001-05-14
2001-01-2072
Research is being conducted at the Georgia Tech Research Institute (GTRI) to develop advanced aerodynamic devices to improve the performance, economics, stability, handling and safety of operation of Heavy Vehicles by using previously-developed and flight-tested pneumatic (blown) aircraft technology. Recent wind-tunnel investigations of a generic Heavy Vehicle model with blowing slots on both the leading and trailing edges of the trailer have been conducted under contract to the DOE Office of Heavy Vehicle Technologies. These experimental results show overall aerodynamic drag reductions on the Pneumatic Heavy Vehicle of 50% using only 1 psig blowing pressure in the plenums, and over 80% drag reductions if additional blowing air were available. Additionally, an increase in drag force for braking was confirmed by blowing different slots.
Technical Paper

Staying Ahead of the Automation: A Vertical Situation Display Can Help

2000-10-10
2000-01-5614
In this paper we present a Vertical Situation Display (VSD) for Flight Management System equipped aircraft. It was developed, implemented and evaluated in the Advanced Concepts Flight Simulator at NASA Ames Research Center. The VSD was designed to support flight crews in managing the vertical flight path when using high levels of aircraft automation inside Terminal Areas.
Technical Paper

Integration of Configuration Design and Analysis of Aircraft

2000-10-10
2000-01-5610
The integration and application of multidisciplinary computer-aided engineering (CAE) software to expedite the configuration and structural designs of aircraft are being attempted. Various interfaces and computer programs have been developed to transfer data between computer aided design (CAD) software, finite element analysis (FEA) codes, computational fluid dynamics (CFD) meshes and control system analysis programs to facilitate multidisciplinary analysis of a vehicle design. The structural, thermal, aerodynamic and control characteristics, and their interactions can be predicted. The computer codes, interfaces and data translators developed, and the modeling and simulation procedures are described herein. The modeling and multidisciplinary analysis of a generic hypersonic vehicle configuration is presented as a test case.
Technical Paper

Photocatalytic Oxidation Technology for Trace Contaminant Control in Aircraft and Spacecraft

1996-07-01
961520
A novel approach to vehicle airborne contaminant removal based on UV illumination of the photoactive semiconductor TiO2 (titania) at room temperature is described. This paper describes fundamental surface chemistry measurements, prototype development, and theoretical models needed for practical application of the technology. The process of incorporating this information into the design of effective air-purifiers for cabin air applications is described.
Technical Paper

Advances in SINDA/FLUINT and SINAPS

1996-07-01
961447
SINDA/FLUINT (formerly SINDA '85) is a computer program used to analyze thermal/fluid systems that can be represented in finite difference, finite element, or lumped parameter form. In addition to conduction and radiation heat transfer, the program is capable of modeling steady or unsteady single- and two-phase flow networks, their associated hardware, and their heat transfer processes. Because it is generalized, versatile, and user-extensible, SINDA/FLUINT is a standard in the aerospace industry for modeling thermal control systems. It is also used in the automotive, aircraft, electronics, petrochemical, and process industries. SINAPS™ (SINDA Application Programming System) is a complete graphical user interface to SINDA/FLUINT. SINAPS is a schematic-oriented pre- and postprocessor that brings modern visualization methods to a simulation code that lacks geometric constraints.
Technical Paper

Recent Aerodynamic Improvements at the Lockheed Martin Low Speed Wind Tunnel

1996-02-01
960903
The Lockheed Martin Aeronautical Systems Company Low Speed Wind Tunnel has been used for aircraft testing and full scale automotive testing since 1967 In 1993, an improvement program was initiated to reduce background noise, improve test section flow quality, and reduce the aerodynamically induced vibrations affecting the main drive The initial aerodynamic work discussed here included optimizing the setting angles of the turning vanes in the first and second comers and modifying the orientation of the test section breather slots Optimizing the turning vane setting angles was required to minimize flow irregularities in the circuit A CFD panel method program was used to study the effects of various turning vane setting angles While the computational study had limitations, it was used to identify large pressure gradients at the outer corners and qualitatively related the effects of flow constriction at the vane trailing edges to the rotation angle of the vanes Final decisions on vane setting angles were based on measured velocity profiles in the second diffuser and upstream of the fan The improved turning vane configurations minimized the separated flow in the second diffuser, increased the uniformity of the flow into the fan, and reduced the flow swirl angle in the test section by approximately 50% Modification of the breather slots and sealing leaks in the circuit reduced the pressure difference acting across the walls of the closed test section by 85% These actions reduced the test section longitudinal static pressure gradient by 33% and reduced the velocity of air leaking into the test section The reduced air leakage lowered the test section background noise 2 dB at frequencies above 2 kHz
Technical Paper

Accident Investigation and Reconstruction Mapping with Aerial Photography

1996-02-01
960894
A system has been developed for investigating and reconstructing vehicular accidents using close-range aerial photography. Accident Investigation and Reconstruction Mapping with Aerial Photography, henceforth referred to as AIRMAP, utilizes a tethered blimp and suspended camera in a close-range aerial survey technique. It produces a high-resolution, color, vertical photograph that can be scaled, digitized, and analyzed in conjunction with other documented evidence. Computer-generated graphics of physical evidence, such as vehicles, tire marks, and pedestrians, can be superimposed over the image to produce a plan view photographic map of the accident scene easily understood by a non-technical audience.
Technical Paper

Current Riveting/Fastening Methodology and Future Assembly Equipment Philosophy

1996-10-01
961866
This paper is focusing on considerations pertaining to riveting/fastening systems and assembly methodology currently in use for large aircraft fuselage structures. Discussion of process principles on which current systems are based is addressing distribution of rivets along the aircraft structure, riveting/fastening systems and equipment flexibility. An attempt was made to predict the most probable future equipment development trends based on the need for more efficiency in all aircraft structural assembly and in high level and final assembly areas.
Technical Paper

Peck Drilling of Composite/Metal Assemblies

1996-10-01
961882
Under Contract No. N00019-93-C-0006 EMD with the Department of the Navy, Bell Helicopter Textron Inc. (BHTI) conducted a Manufacturing Process Verification Test as part of the V-22 Engineering Manufacturing Development process. The objective of this test was to develop a “One Step” drilling solution for peck drilling close tolerance holes in V-22 major assemblies. These assemblies consist of Titanium / Graphite / Titanium and Aluminum / Graphite compositions. The V-22 is a graphite / epoxy composite structure that has metal detail parts mechanically attached to the basic structure. Attachment of these detail parts is accomplished with two piece titanium fasteners that require a close tolerance of .003″ per hole. To achieve this tolerance a drill / ream process is currently used.
Technical Paper

A Flexible Development System for Automated Aircraft Assembly

1996-10-01
961878
McDonnell Douglas Aircraft in St. Louis, MO manufacturers various transport and fighter military aircraft such as the C-17 and the F/A-18. With shrinking military budgets and increased competition, market forces demand high quality parts at lower cost and shorter lead times. Currently, a large number of different fastener types which include both solid rivets and interference bolts are used to fasten these assemblies. The majority of these fasteners are installed by hand or by using manually operated C-Frame riveters. MDA engineers recognized that in order to reach their goals they would be required to rethink all phases of the assembly system, which includes fastener selection, part fixturing and fastener installation methods. Phase 1 of this program is to identify and to develop fastener installation processes which will provide the required flexibility. The EMR fastening process provides this flexibility.
Technical Paper

The Design of a Flexible Fixture for Aircraft Assembly

1996-10-01
961885
Two new concept of flexible fixture subsystem (FFS) for aircraft wing spar assembly are introduced in this paper. The advantages and characteristics of FFS are discussed and compared with the current assembly method and fixtures. The objective of FFS is to replace the dedicated tooling and be able to quickly reconfigure itself for new types of spars. The fixture enables a family of spars to be mounted and assembled in the same tooling. Left- and right-hand side spars, varying lofts(spar cap angles), height, and depths are all accommodated on the same tool, within its envelop.
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