Browse Topic: Lightning

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Lightning eMotors adapts to changing electrification market22TOFHP08_0508/01/2022
A growing number of commercial truck fleets are moving to electric vehicles, driven partially by government mandates and support funding. For suppliers like Lightning eMotors, that means adapting to changing markets and creating designs for both a range of new vehicles and techniques that efficiently convert aging internal-combustion engine (ICE) vehicles to electrified powertrains. Lightning is currently expanding its efforts in repowering ICE trucks and buses with electric systems, but it's also inked new vehicle partnerships with General Motors and school bus supplier Blue Bird Corp. Founded in 2008, Lightning began with a focus on hybrid vehicles but switched to fully electric designs in 2016.
Costlow, Terry
Magazine Article
Design and Computational Investigations of Aerobot for Titan with maneuverability using momentum wheel and propeller equipped with droppable weather stations 2022-26-119105/26/2022
Titan, Saturn’s largest moon and the only celestial body which is found to have a landmass composed of liquid hydrocarbons. Nitrogen – The building block of all life that exists on earth is found to be abundant in Titan’s atmosphere of up to 97%. Aerobots provide a great platform for exploring a celestial body with an atmosphere such as Titan. They have modest power requirements, longer mission duration, and can cover a longer distance in a shorter time. They are powered by Radioisotope Thermoelectric Generator for optimal mission life. Aerobot’s altitude can be altered by varying the temperature of the air inside the balloon and yaw can be controlled using Reaction Wheel and a motor-driven propeller for forwarding thrust. The proposed Aerobot will be equipped with four miniature deployable fixed weather stations that can be dropped from the aerobot to titan’s surface. They can be deployed at diverse locations such as the equator and Polar Regions to deeply explore the Titan’s climate
Raja, Manoj Kumar, Sivasankaran, Abinash Nataraj, Saravana Mohan, Haribalan, Thangavel, Sabari, R, Vijayanandh, Gnanasekaran, Raj Kumar
Technical Paper
Method for Performing Indirect Lightning Test Simulation2022-26-118205/26/2022
From the statistics it has been observed that major qualification test failures in aerospace system are from lightning tests. These failures lead to major cost and schedule implications as fixing these issues later in the design usually requires a product re-spin. To avoid such failures, testing of critical interfaces using simulation allows engineers to investigate the behavior of the product/system in different scenarios and visualize the effect of these changes at an earlier stage in the design. Achieving this through simulation also eliminates the need of heavy costs associated with physical prototyping & testing. The existing simulation techniques use prebuilt & formula-based lightning waveform models and also do not take into consideration the end to end impedance characteristics like cable impedance, remote impedance, etc. With these available techniques, achieving results closer to practical scenarios is difficult. To overcome some of these challenges, this paper presents a
Rajeurs, Ajaypal, Gouda, Vidyadhar
Technical Paper
ASSEMBLED COUPLING ENVELOPE, THREADLESS - FLEXIBLE, FIXED CAVITY, CURRENT CARRYING, SELF BONDING, ENVELOPE DIMENSIONSAS7511B (Current)12/22/2020
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Technical Standard
Identification and Assessment of Damage to Composite Aircraft Structures Training DocumentAIR6825-TEST-REC (Historical)08/03/2020
Individuals who complete the applicable modules aligned with this training document will be able to define the type of damage, define the extent of damage, determine if further inspection is required, evaluate the damage against published allowable damage limits, and provide accurate documentation of the damage. The intended outcome of the training is increased safety such that no aircraft is released with unknown damage and that the aircraft meets continued airworthiness requirements. The goal is to change the culture from damage discovery to damage reporting while also reducing or eliminating flight delays due to incorrect or insufficient information. Teaching levels have been assigned to the curriculum to define the knowledge, skills, and abilities graduates will need. Minimum hours of instruction have been provided to ensure adequate coverage of all subject matter including lecture and practical exercise. These minimums may be exceeded and may include an increase in the total
AMS CACRC Commercial Aircraft Composite Repair Committee
Information Report
Identification and Assessment of Damage to Composite Aircraft Structures Training DocumentAIR6825 (Current)08/03/2020
Individuals who complete the applicable modules aligned with this training document will be able to define the type of damage, define the extent of damage, determine if further inspection is required, evaluate the damage against published allowable damage limits, and provide accurate documentation of the damage. The intended outcome of the training is increased safety such that no aircraft is released with unknown damage and that the aircraft meets continued airworthiness requirements. The goal is to change the culture from damage discovery to damage reporting while also reducing or eliminating flight delays due to incorrect or insufficient information. Teaching levels have been assigned to the curriculum to define the knowledge, skills, and abilities graduates will need. Minimum hours of instruction have been provided to ensure adequate coverage of all subject matter including lecture and practical exercise. These minimums may be exceeded and may include an increase in the total
AMS CACRC Commercial Aircraft Composite Repair Committee
Information Report
Electrically Non-Conductive Ladder Fall ProtectionTBMG-3619403/01/2020
NASA’s Kennedy Space Center developed an electrically non-conductive ladder fall protection system for the Launch Complex (LC) 39B lightning towers. The towers include a 100-foot fiberglass mast at the top of the tower structure. The fiberglass masts insulate the metallic tower structure from the lightning strike protection system that is housed at the top of the fiberglass masts.
Magazine Article
Understanding the Impact of Standardized SAE Waveform Parameter Variation on Artificial Lightning Plasma, Specimen Loading, and Composite Material Damage01-13-01-000202/18/2020
Previous works have established strategies to model artificial test lightning plasma with specific waveform parameters and use the predicted plasma behavior to estimate test specimen damage. To date no computational works have quantified the influence of varying the waveform parameters on the predicted plasma behavior and resulting specimen damage. Herein test standard Waveform B has been modelled and the waveform parameters of “waveform peak,” “rise time,” and “time to reach the post-peak value” have been varied. The plasma and specimen behaviors have been modelled using the Finite Element (FE) method (a Magnetohydrodynamic FE multiphysics model for the plasma, a FE thermal-electric model for the specimen). For the test arrangements modelled herein, it has been found that “peak current” is the key parameter influencing plasma properties and specimen damage. A 10% increase in peak current magnitude (and resulting 21% increase in action integral) results in a 12% increase in plasma peak
Millen, Scott, Murphy, Adrian, Abdelal, Gasser, Catalanotti, Giuseppe
Journal Article
Hardening Lightweight Metal Foams with NanocoatingTBMG-3581801/01/2020
Bones are strong and stable and can cope with loads almost as well as steel. But despite their strength, they are light enough to be easily moved by humans and animals. The secret lies in the combination of a hard, exterior shell that encases a porous lattice-like network of bone tissue in the interior of the bone. This structure saves on material and reduces weight.
Magazine Article
S400 Copper Media Interface Characteristics Over Extended DistancesAS5643/1A (Current)07/09/2019
This SAE Aerospace Standard (AS) establishes guidelines for the use of IEEE-1394-2008 Beta (formerly IEEE-1394b) as a data bus network in military and aerospace vehicles. It encompasses the data bus cable and its interface electronics for a system utilizing S400 over copper medium over extended lengths. This document contains extensions/restrictions to “off-the-shelf” IEEE-1394 standards, and assumes that the reader already has a working knowledge of IEEE-1394. This document does not identify specific environmental requirements (electromagnetic compatibility, temperature, vibration, etc.); such requirements will be vehicle-specific and even LRU-specific. However, the hardware requirements and examples contained herein do address many of the environmental conditions that military and aerospace vehicles may experience. One should refer to the appropriate sections of MIL-STD-461E for their particular LRU, and utilize handbooks such as MIL-HDBK-454A and MIL-HDBK-5400 for guidance. This
AS-1A Avionic Networks Committee
Technical Standard
X-Ray Study of Low-Density MaterialsTBMG-3390303/01/2019
It's hard to get an X-ray image of low-density material like tissue between bones because X-rays just pass right through like sunlight through a window. Sandia studies myriads of low-density materials, from laminate layers in airplane wings to foams and epoxies that cushion parts. So they borrowed and refined a technique from the medical field, X-ray phase contrast imaging, to look inside the softer side of things. The technique measures not just the number of X-ray photons that get through the sample, as in conventional X-ray imaging, but also the phase of the X-rays after they pass through, offering a complete look at interfaces inside a structure.
Magazine Article
Plasma Generator Using Spiral ConductorsTBMG-3370302/01/2019
NASA's Langley Research Center has developed a patented SansEC sensor technology for use in many different areas, including tall structures and wind turbines. The SansEC technology is a proven wireless sensing platform capable of measuring the electrical impedance of physical matter in proximity to the sensor based on a change in its resonance response. The SansEC sensor also exhibits a unique characteristic to disperse the lightning strike current to help mitigate lightning damage. In a turbine blade application, an array of SansEC sensors will cover the surface area of the composite blade, providing both lightning mitigation and damage sensing. NASA Langley is seeking industrial partners/licensees to commercialize this technology. The research team at NASA Langley is available to assist with further development.
Magazine Article
Streamlining EMC Solutions for Avionics InterfacesTBMG-3377302/01/2019
Lightning strikes to jet airliners are common - about once every 1000 flight hours. The DO-160G standard, Environmental Conditions and Test Procedures for Airborne Equipment, is a standard for the environmental testing of avionics hardware. Many airplane manufacturers specify DO-160G Section 22, lightning induced transient susceptibility, as a requirement for critical systems like guidance, radars, communications, engine control, and heat and air controls. Aircraft fuselage, wing and tail flight controls, wing tips, fin tips, engine nacelles, and landing gear are the areas most likely to be hit by lightning strikes.
Magazine Article
Streamlining EMC Solutions for Avionics Interfaces19AERP02_0402/01/2019
Lightning strikes to jet airliners are common - about once every 1000 flight hours. The DO-160G standard, Environmental Conditions and Test Procedures for Airborne Equipment, is a standard for the environmental testing of avionics hardware. Many airplane manufacturers specify DO-160G Section 22, lightning induced transient susceptibility, as a requirement for critical systems like guidance, radars, communications, engine control, and heat and air controls. Aircraft fuselage, wing and tail flight controls, wing tips, fin tips, engine nacelles, and landing gear are the areas most likely to be hit by lightning strikes. Modern aircraft are designed with fly by wire systems for flight controls. Fly by wire means that inputs from either flight control computers or pilot manual inputs are transmitted electrically to a servomotor, which controls flight control actuators. Communication interfaces for these flight control systems can be implemented on an RS-485 physical layer. Communication
Magazine Article
Aircraft Lightning ZoneARP5414B (Current)12/05/2018
This SAE Aerospace Recommended Practice (ARP) defines lightning strike zones and provides guidelines for locating them on particular aircraft, together with examples. The zone definitions and location guidelines described herein are applicable to Parts 23, 25, 27, and 29 aircraft. The zone location guidelines and examples are representative of in-flight lightning exposures.
AE-2 Lightning Committee
Recommended Practice
U.S. DoD orders 255 Lockheed Martin F-35 military combat aircraft in $22.7B dealSAE-MA-0314611/16/2018
Lockheed Martin Aeronautics Co., part of Lockheed Martin Corp., in Fort Worth, Texas, won a $22.7 billion contract from the U.S. Department of Defense (DoD) to deliver 255 of its F-35 fifth-generation military combat aircraft. The Naval Air Systems Command, Patuxent River, Maryland, issued the contract modification to a previously awarded firm-fixed-price advanced acquisition contract (N00019-17-C-0001) for Lockheed Martin’s F-35 Lightning II family of single-seat, single-engine, all-weather stealth multirole fighters designed to perform ground-attack and air-superiority missions.
E., Courtney
Magazine Article
ASSEMBLED COUPLING ENVELOPE, THREADLESS - FLEXIBLE, FIXED CAVITY, CURRENT CARRYING, SELF BONDING, ENVELOPE DIMENSIONSAS7511A (Historical)04/18/2018
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Technical Standard
Sequential/Simultaneous Multi-Metallized Nanocomposites (S2M2N)TBMG-2798712/01/2017
NASA Langley Research Center has developed a method to create Sequential/Simultaneous Multi-Metallized Nanocomposites (S2M2N) via supercritical fluid (SCF) sequential or simultaneous multi-metal infusion. The SCF infusion process provides deep impregnation of metal nanoparticles into a variety of materials, including those with challenging topographies and complex structures. The resulting multi-metallized nanocomposites can possess high electrical conductivity, permittivity, permeability, wear resistance/anti-penetrant, and radiation shielding along with high toughness.
Magazine Article
Thermoplastic Fuselage DemonstratorTBMG-2766110/01/2017
Porcher Industries Badinières, France +33 (0)4 74 43 10 10
Magazine Article
ASSEMBLED COUPLING ENVELOPE, THREADLESS - FLEXIBLE, FIXED CAVITY, CURRENT CARRYING, SELF BONDING, ENVELOPE DIMENSIONSAS7511 (Historical)09/07/2017
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Technical Standard
Lightning Protection and Detection SystemTBMG-2615501/01/2017
NASA’s Langley Research Center has developed a sensor technology for structural health monitoring on composite aircraft surfaces. When conventional aircraft are struck by lightning, the result can range from no damage to serious damage requiring extensive repairs that can take the airplane out of service for an extended period of time. The SansEC technology is a proven wireless sensing platform capable of measuring the electrical impedance of physical matter in proximity to the sensor based on a change in its resonance response. The sensor also exhibits a unique characteristic to disperse the lightning strike current to help mitigate lightning damage. In this application, an array of SansEC sensors will cover a selective area of the aircraft surface, providing both mitigation and damage sensing.
Magazine Article
Electric Field Quantitative Measurement System and MethodTBMG-2613901/01/2017
NASA Langley Research Center’s Electric Field Imaging (EFI) system is the only noncontact method capable of quantitatively measuring the magnitude and direction of electrostatic fields in near- and far-field applications. Based on low-cost, commercially available components, the EFI system uses measurement of very-low-current, human-safe electric fields to construct a three-dimensional image of objects and people based on their dielectric properties. This platform technology, originally developed for measurement of the efficacy of electrical shielding around cables, could be optimized for a variety of applications, including medical imaging, security and detection, weather and natural disaster prediction, and nondestructive evaluation of composites and insulators. The EFI system has the potential to offer a lower-cost, portable, and safer alternative to the imaging systems currently used in these applications.
Magazine Article
Aerospace & Defense Technology: June 201616AERP0606/01/2016
Digital Design Tools Simulating Thermal Expansion in Composites with Expanded Metal Foil for Lightning Protection Rugged Computing Designing VME Power Systems with Standard Modules Optical Sensors Optical Ice Sensors for UAVs Rotorcraft Technology Rotorcraft Icing Computational Tool Development RF & Microwave Technology Curled RF MEMS Switches for On-Chip Design: Design Software Supports BAE System's Mixed-Signal Chip Design
Magazine Issue
Lightweighting Focus for TE's Connectivity SolutionsTBMG-2313510/01/2015
TE Connectivity recently announced two new aerospace connectivity solutions that offer substantial weight savings: its COPALUM Lite sealed terminals and splices, and its Raychem INSTALITE lightweight braid system.
Magazine Article
Aerospace - Lightning Effects on Hydraulic Transport Elements on AircraftAIR6185 (Current)08/28/2015
This SAE Aerospace Information Report (AIR) describes hydraulic system design and installation to minimize the effects of lightning, especially when the aircraft structure is composite. Techniques for effective electrical bonding, hydraulic system lightning protection, and lightning protection verification techniques are discussed.
A-6A1 Commercial Aircraft Committee
Information Report
Fiber-Optic Sensor for Aircraft and Structure Lightning MeasurementTBMG-2242907/01/2015
An optical-fiber sensor based on Faraday Effect was developed for measuring total lightning current. Designed for aircraft installation, it is lightweight, non-conducting, structure conforming, and is immune to electromagnetic interference, hysteresis, and saturation. It can also be used on windmills, lightning towers, and can help validate lightning detection network measurements.
Magazine Article
NASA Launch Pads Protected Against Lightning-Induced Power SurgesTBMG-2066810/01/2014
Circuit protection components Littelfuse Chicago, IL 773-628-1000
Magazine Article
KSC Spaceport Weather Data ArchiveTBMG-1989206/01/2014
The Spaceport Weather Data Archive provides a fully searchable database of weather data gathered at Kennedy Space Center and the Cape Canaveral Air Force Station. Weather data includes wind, temperature, and humidity data from a surface meteorological tower network; upper air soundings from both weather balloons and radar wind profilers; and data from the extensive rain gauge network. Not only can the user easily retrieve data and download it, but the user can also view graphically the weather data on a map overlay. For example, the user can enter search criteria to view all lightning strikes ending at a particular date/time, and graphically see the lightning strikes color-coded based on elapsed time for the prior seven hours. A unique feature of the software is the capability to invoke an automated playback for cloud-to-ground lightning events on a geographic overlay for a selected date and time interval.
Magazine Article
LED DriversTBMG-1965305/01/2014
SL Power Electronics (Ventura, CA) has introduced its new LE Series of LED drivers. Available in 10 models from 75 to 300 watts, the constant current LED drivers enable highly efficient LED lighting for applications that require more than eight hours per day of operating life. Featuring a wide input voltage range of 90 to 305 VAC, up to 95 percent efficiency and the ability to survive lightning strikes, the LE-Series have UL 8750 and EN61347 safety approvals with an IP67 rating and are housed in a waterproof metal case in order to withstand hot and cold temperatures in outside installations.
Magazine Article
Aerospace & Defense Technology: February 201414AERP0202/03/2014
Thermal simulation and testing of expanded metal foils for lightning protection With the implementation of major aircraft structures fabricated from carbon fiber reinforced plastic materials, lightning protection has become a more complicated issue for designers and engineers to solve. Electronics take charge Digital controls are handling more engine control tasks on a wider range of aircraft.
Magazine Issue
Aircraft Structure Paint Thickness and Lightning Swept Stroke Damages2013-01-213509/17/2013
During its flight an aircraft can be struck by lightning and the induced high current will require a highly conductive airframe skin structure in order for it to propagate through with minimum damage. However an aircraft skin is generally coated with paint and the airframer does not always have control on the paint thickness. Paint thickness generates heightened concerns for lightning strike on aircraft, mainly because most of coatings dedicated to that purpose are non-conductive. Using insulating material or non-conductive coating with certain thickness may contribute to or increase damage inflicted by the swept stroke lightning energy, even on metallic structures Due to its high relative permittivity, a non-conductive paint or coating on a fuselage skin surface will contribute to slow down the lightning current propagation through structure. With this comes the risk of increasing heat that will favor structural damage and possible melt through. The correlation between paint thickness
Moupfouma, Fidele
Journal Article
Electromagnetic Protection Hazards on Composite versus Metallic Aircraft2013-01-215709/17/2013
The lightning represents a fundamental threat to the proper operation of aircraft systems. For aircraft protection, Electromagnetic Compatibility requires conductive structure that will provide among all, electromagnetic shielding and protection from HIRF and atmospheric electricity threat. The interaction of lightning with aircraft structure, and the coupling of induced energy with harnesses and systems inside the airframe, is a complex subject mainly for composite aircraft. The immunity of systems is governed by their susceptibility to radiated or conducted electromagnetic energy. The driving mechanism of such susceptibility to lightning energy is the exposure to the changing magnetic field inside the aircraft and IR voltage produced by the flow of current through the structural resistance of the aircraft. The amplitude of such magnetic field and IR voltage is related to the shielding effectiveness of the aircraft skin (wiremesh, composite conductivity). However, it is also known
Moupfouma, Fidele, Klim, Zdzislaw, Skorek, Adam
Journal Article
Lightning Requirements: Where They Come From and How to Analyze Their Impact2012-01-214910/22/2012
Many avionics and aircraft equipment manufacturers use DO-160 [Ref. 1] Section 22 to test their equipment for indirect effects of lightning without understanding why they are testing to specific values. Many aircraft manufacturers struggle with determining the level of indirect lightning that will be acceptable for their vehicle and what level of requirements they need to pass down to the avionics and aircraft equipment manufacturers. Organizations like SAE and RTCA, Inc. work to collect data on lightning and spend countless hours assimilating the information and developing documents to help engineers use the information. They struggle with knowing what data is pertinent and how it will be received and used by the engineering community. This paper walks through the process of how the lightning levels are developed, how the levels get selected for a particular application, and how to use this information to perform an analysis of the survivability of a specific circuit in an electronic
Harrington, James
Technical Paper
Software Creates and Analyzes Lightning Protection Solutions for Wind TurbinesTBMG-1465809/01/2012
Highvoltage.dk is a Danish consulting engineering firm with expertise in lightning protection and high-voltage engineering. The company, founded in 2005, tackles complex problems such as general high-voltage design engineering for the power industry, lightning protection concepts and findings for wind turbines, and high-voltage material tests. The engineers at Highvoltage.dk are experienced users of numerical analysis tools to simulate magnetic and electric fields, current distribution, and lightning attachment points.
Magazine Article
High-Voltage, Low-Power BNC Feedthrough TerminatorTBMG-1386306/01/2012
This innovation is a high-voltage, lowpower BNC (Bayonet Neill–Concelman) feedthrough that enables the user to terminate an instrumentation cable properly while connected to a high voltage, without the use of a voltage divider. This feedthrough is low power, which will not load the source, and will properly terminate the instrumentation cable to the instrumentation, even if the cable impedance is not constant.
Magazine Article
An Advanced Circuit Protection Approach for RF InterfacesTBMG-1228812/01/2011
One aspect that sets circuit protection for radio frequency (RF) apart from other types of applications is the range of frequencies in which RF circuits operate. With abbreviated clock cycles, the transition time of the data leaves little room for error. Transitions must be clean and reliable to ensure the integrity of the data and interface. Circuit protection characteristics such as capacitance become important in terms of their effect on these high-frequency signals and it often complicates the design.
Magazine Article
Data Acquisition System Monitors Lightning StrikesTBMG-1191511/01/2011
Genesis HighSpeed data acquisition system and Perception software HBM Marlboro, MA 508-624-4500 www.hbm.com
Magazine Article
Probability Assessment of the Fuel Tank Structural Feature Failures2011-01-251810/18/2011
The paper provides an approach to establish compliance with current regulatory standards applicable to lightning protection of the fuel tank structure for Non-Fault Tolerant Feature Failures (NFTFF) through a numerical probability assessment. The proposed procedure is using the criteria defined in the FAA Policy Guidance for fuel tank structural lightning protection and is aligned with the regulatory path described as petitioning for an exemption. Failure modes of structural components for which fault tolerance has been shown to be impractical need to be addressed and the overall likelihood of fuel vapour ignition due to these failure modes must be shown to be extremely improbable. In order to accomplish this, the quantitative assessment of the overall probability of fuel vapour ignition is performed, along with all relevant data to support the probabilities determined for the purpose of this analysis. The relevant non-fault tolerant structural design areas that may contribute to
Klim, Zdzislaw H., Skorek, Adam W.
Journal Article
Grommet Hole Reinforcement and Lightning Strike Protection in Composite Structural Assembly2011-01-261010/18/2011
Aircraft design and assembly challenges include provision of hole protection from lightning strike in fastened joints, especially in the vicinity of fuel tanks or electrical services. Installation of interference fit fasteners helps minimize the effect of lightning strike and also enhances the durability and load transfer ability of the joint. However, these are known to cause laminate damage during installation which can degrade the fastener system performance. Use of a pre-installed expanded grommet into the hole prior to installing interference fit fasteners has been shown to greatly enhance the effectiveness of the joint as well as the conductivity of electrical current into the structure to minimize arcing or plasma discharge at the fastener in the event of lightning strike. The Fatigue Technology (FTI) GromEx® system provides such hole protection for fastener installations into composites, allowing for the installation of interference fit fasteners without detrimental impact to
Reid, Len, Ransom, Joy, Wehrmeister, Mark
Journal Article
Using Aspheric Optics in Complex Lens DesignsTBMG-1107809/01/2011
Optical design engineers often discuss the use of aspheres to reduce element count, but they seldom put the discussion into real-time practice, often fearing that the more complex fabrication process of the asphere itself overwhelms the advantages that they might gain.
Magazine Article
Fiber-Optic Magnetic-Field-Strength Measurement System for Lightning DetectionTBMG-912502/01/2011
A fiber-optic sensor system is designed to measure magnetic fields associated with a lightning stroke. Field vector magnitudes are detected and processed for multiple locations. Since physical limitations prevent the sensor elements from being located in close proximity to highly conductive materials such as aluminum, the copper wire sensor elements (3) are located inside a 4-cubic-in. (≈66-cubic-cm) plastic housing sensor head and connected to a fiber-optic conversion module by shielded cabling, which is limited to the shortest length feasible. The signal path between the conversion module and the avionics unit which processes the signals are fiber optic, providing enhanced immunity from electromagnetic radiation incident in the vicinity of the measurements. The sensors are passive, lightweight, and much smaller than commercial B-dot sensors in the configuration which measures a three-dimensional magnetic field. The system is expandable, and provides a standard-format output signal
Magazine Article
Fiber-Optic Magnetic-Field-Strength Measurement System for Lightning DetectionTBMG-TB-00912502/01/2011
Fiber optics used for signal paths provide enhanced immunity from electromagnetic radiation incident in the vicinity of the measurements. A fiber-optic sensor system is designed to measure magnetic fields associated with a lightning stroke. Field vector magnitudes are detected and processed for multiple locations. Since physical limitations prevent the sensor elements from being located in close proximity to highly conductive materials such as aluminum, the copper wire sensor elements (3) are located inside a 4-cubic-in. (≈66-cubic-cm) plastic housing sensor head and connected to a fiber-optic conversion module by shielded cabling, which is limited to the shortest length feasible. The signal path between the conversion module and the avionics unit which processes the signals are fiber optic, providing enhanced immunity from electromagnetic radiation incident in the vicinity of the measurements. The sensors are passive, lightweight, and much smaller than commercial B-dot sensors in the
Magazine Article
Situational Lightning ClimatologiesTBMG-845609/01/2010
Research has revealed distinct spatial and temporal distributions of lightning occurrence that are strongly influenced by large-scale atmospheric flow regimes. It was believed there were two flow systems, but it has been discovered that actually there are seven distinct flow regimes.
Magazine Article
Lightning Monitoring System Helps Protect ShuttleTBMG-792705/01/2010
Genesis HighSpeed data acquisition products HBM Marlborough, MA 800-578-4260 www.hbm.com/highspeed
Magazine Article
Off-Road Tire Fire Handling GuidelinesJ2828_201004 (Historical)04/23/2010
This SAE Informational report applies to tires used on off-road, rubber-tired work machines as identified in SAE J1116. This SAE document provides general guidelines for proper handling of potential and actual off-road tire fires and possible related explosions.
MTC8, Tire and Rim
Information Report
AS46772 Lead, Electrical (for Static Bonding Purposes) Unsuitable for Lightning Strike PurposesAS46772-4 (Current)04/01/2010
No scope available.
Engine and Airframe Technical Standards Committee (TSC)
Technical Standard
Piezoelectric Switch for Controlling LightingTBMG-1439603/01/2010
Piezoelectric materials convert mechanical energy into electrical energy, and electrical energy into mechanical energy. They generate electrical charges in response to mechanical stress and generate mechanical displacement and/or force when subjected to an electric current.
Magazine Article
Improvements in a Lightning-Measuring InstrumentTBMG-TB-00705201/22/2010
Some improvements have been made in the instrument described in "Instrument Records Magnetic Fields Generated by Lightning" (KSC-11769) NASA Tech Briefs, Vol. 19, No. 4 (April 1995), page 38. To conserve battery energy, the instrument was made to record the output of only one of three mutually orthogonal loop antennas and to operate in a "sleep" mode except when "awakened" by a lightning strike. Unfortunately, with this energy-conserving strategy, sometimes even a nearby lightning strike could fail to wake the system up on time to record the first strike. The improvements, directed toward overcoming this trigger deficiency, include (1) replacing the "sleep" mode with a mode in which the signals from all three antennas are sampled sequentially at a reduced rate and multiplexed onto one channel and (2) modifying the triggering scheme and the "awake" mode so that once a signal in at least one channel exceeds the trigger threshold, the signals from all three antennas are sampled at a high
Magazine Article
MIL-STD-1553 Physical Layer for Time-Triggered Networks2009-01-314711/10/2009
Time Triggered networking technologies such as TTP (Time Triggered Protocol) are beginning to be used in critical aerospace applications such as flight controls. While TTP provides stringent specifications for determinism and fault tolerance, it does not define a physical layer. TTP's “de facto” physical layer, RS-485, includes shortcomings in a number of areas. These include a relatively low minimum transmitter voltage, low receiver threshold, along with a lack of specificity in a number of areas. The latter include bus signal levels, transmitter zero-crossing distortion and receiver zero-crossing tolerance, isolation method, terminal output noise, common mode and noise rejection, and input impedance. MIL-STD-1553, which has been deployed in flight and mission critical military applications for decades, defines a highly proven and robust physical layer. This paper presents MIL-STD-1553's physical layer as a candidate for use with TTP.
Glass, Mike
Technical Paper
Multiphysics Modeling Simplifies Analysis of Electrical and Electromagnetic EffectsTBMG-317609/01/2008
The Saab Group has 17 business units, which are split into defense and security, systems and products, and aeronautics. Over the years, the company has taken advantage of the many paradigm shifts that have taken place in engineering analysis. One example is implementing comprehensive engineering methodologies that combine traditional experiments and testing with newer tools such as computer modeling and simulation. In the 1980s, Saab began applying largescale computer simulations, which were used to verify the lightning-protection components in the wings of the Gripen fighter aircraft.
Magazine Article
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