Browse Topic: Lightning

Items (338)
The environment and test waveforms defined in this SAE Aerospace Recommended Practice (ARP) account for the best lightning data and analysis currently available. The quantified environment and levels herein represent the minimum currently required by certifying authorities, which is consistent with the approach applied in related lightning documents. Lightning, like other weather phenomenon, is probabilistic in nature. Levels and waveforms vary considerably from one flash to the next. Within this document, standardized voltage and current waveforms have been derived to represent the lightning environment external to an aircraft. These standardized waveforms are used to assess the effects of lightning on aircraft. The standardized external current waveforms have, in turn, been used to derive standardized transient voltage and current test waveforms that can be expected to appear on cable bundles and at equipment interfaces within an aircraft. When deriving these latter internal induced
AE-2 Lightning Committee
This SAE Aerospace Information Report (AIR) describes the aspects of hydraulic system design and installation to minimize the effects of lightning. Techniques for effective electrical bonding, hydraulic system lightning protection, and lightning protection verification techniques are discussed
A-6A1 Commercial Aircraft Committee
Northrop Grumman Corporation is developing AN/APG-85, an advanced Active Electronically Scanned Array (AESA) radar for the F-35 Lightning II. Northrop Grumman currently manufactures the AN/APG-81 active electronically scanned array (AESA) fire control radar, the cornerstone to the F-35 Lightning II’s sensor suite
The Current Icing Product (CIP; Bernstein et al. 2005) and Forecast Icing Product (FIP; Wolff et al. 2009) were originally developed by the United States’ National Center for Atmospheric Research (NCAR) under sponsorship of the Federal Aviation Administration (FAA) in the mid 2000’s and provide operational icing guidance to users through the NOAA Aviation Weather Center (AWC). The current operational version of FIP uses the Rapid Refresh (RAP; Benjamin et al. 2016) numerical weather prediction (NWP) model to provide hourly forecasts of Icing Probability, Icing Severity, and Supercooled Large Drop (SLD) Potential. Forecasts are provided out to 18 hours over the Contiguous United States (CONUS) at 15 flight levels between 1,000 ft and FL290, inclusive, and at a 13-km horizontal resolution. CIP provides similar hourly output on the same grid, but utilizes geostationary satellite data, ground-based radar data, Meteorological Terminal Air Reports (METARS), lightning data, and voice pilot
Rugg, AllysonHaggerty, JulieAdriaansen, DanielSerke, DavidEllis, Scott
Previous artificial lightning strike direct effect research has examined a broad range of specimen design parameters. No works have studied how such specimen design parameters and electrical boundary conditions impact the dissipation of electric current flow through individual plies. This article assesses the influence of carbon fiber composite specimen design parameters (design parameters = specimen size, shape, and stacking sequence) and electrical boundary conditions on the dissipation of current and the spread of damage resulting from Joule heating. Thermal-electric finite element (FE) modelling is used and laboratory scale (<1 m long) and aircraft scale (>1 m long) models are generated in which laminated ply current dissipation is predicted, considering a fixed artificial lightning current waveform. The simulation results establish a positive correlation between the current exiting the specimen from a given ply and the amount of thermal damage in that ply. The results also
Millen, ScottKumar, VipinMurphy, Adrian
This document is intended to be a user’s manual to AC 25.954-1 on acceptable means of compliance for applicants with regards to § 25.954 at Amendment 25-146 and to encourage a consistent approach to be applied across industry. This document is also intended to be a user’s manual to AMC 25.954 on acceptable means of compliance for applicants with regards to EASA CS 25.954 at Amendment 26. The FAA Advisory Circular (AC) and the EASA Acceptable Means of Compliance (AMC) documents appear to provide equivalent guidance, using identical wording in most sections. Applicants should coordinate with their certifying authority to ensure that their proposed approach is acceptable, and the means of compliance and compliance data planned are sufficient for certification. It is recommended that the applicant verify that use of the guidance in this document is acceptable to their certifying authority. Further recommendations regarding coordination with the certification authority are provided
AE-2 Lightning Committee
This SAE Aerospace Standard (AS) provides general design and test requirements for a flat cut-off pressure compensated, variable delivery hydraulic pump for use in a civil aircraft hydraulic system with a rated system pressure up to 5000 psi (34500 kPa). NOTE: Hydraulic pumps may incorporate features such as a clutch in the input drive, which will not be covered by this standard
A-6C4 Power Sources Committee
This SAE Aerospace Information Report (AIR) is limited to the subject of aircraft fuel systems and the questions concerning the requirements for electrical bonding of the various components of the system as related to Static Electric Charges, Fault Current, Electromagnetic Interference (EMI) and Lightning Strikes (Direct and Indirect Effects). This AIR contains engineering guidelines for the design, installation, testing (measurement) and inspection of electrical bonds
AE-5A Aerospace Fuel, Inerting and Lubrication Sys Committee
Fireflies have sparked the inspiration of MIT researchers. Taking a cue from nature, they built electroluminescent soft artificial muscles for flying, insect-scale robots. The tiny artificial muscles that control the robots’ wings emit colored light during flight
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 a 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 a 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
Raja, Manoj KumarSaravana Mohan, HaribalanThangavel, SabariRaja, VijayanandhGnanasekaran, Raj KumarSivasankaran, Abinash Nataraj
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
This ARP provides detailed information, guidance, and methods in support of the Federal Aviation Administration (FAA) Advisory Circular (AC) 20-136. AC 20-136 provides a means, but not the only means, for demonstrating compliance with Title 14 of the Code of Federal Regulations (14 CFR) 23.1306 (Amendment 23-61), 23.2515 (Amendment 23-64), 25.1316, 27.1316, and 29.1316. It is also intended for this ARP to provide the same information, guidance, and methods, to the European Aviation Safety Agency (EASA) certification specifications CS 23.1306 (Amendment 23/4), 23.2515 (Amendment 23/5), 25.1316, 27.1316, and 29.1316, and associated Acceptable Means of Compliance (AMC) 20-136. This ARP provides references relevant to identifying: (1) acceptance criteria for the indirect effects of lightning compliance approaches, (2) verification (analysis and test) methods including those associated with multiple stroke and multiple burst, (3) recommended design options to optimize needed system immunity
AE-2 Lightning Committee
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, ScottMurphy, AdrianAbdelal, GasserCatalanotti, Giuseppe
Carbon fiber reinforced plastic (CFRP) has been used in automobiles as well as airplanes. Because of its light weight and high strength, CFRP is a good choice for making vehicle bodies lighter, which would improve fuel economy. Conventional metal bodies provide a convenient body return for electric wiring and offer good shielding against electromagnetic fields. Although CFRP is a conductor, its conductivity is much lower than that of metals. Therefore, CFRP bodies are usually not useful for electric wiring. In thunderstorms, an automotive body is considered to be a Faraday cage that protects the vehicle’s occupants from the potential harms of lightning. Before CFRP becomes widely applied to automotive bodies, its electric and electromagnetic properties need to be investigated in order to determine whether it also works as a Faraday cage against lightning. In this article, CFRP and metal body vehicles were tested under artificial lightning. The electric discharging caused by the
Alkhteeb, Sultan A.Oho, ShigeruNagashima, YukiShimizu, HiroyukiNishimura, SeisukeMakishima, Hiroshi
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
This SAE Aerospace Standard (AS) defines the requirements for a threadless, flexible, self-bonding coupling assembly which, when installed on machined fixed-cavity ferrules, provides a flexible connection for joining tubing and components in aircraft fuel, vent, or other systems. This assembled coupling, hereafter referred to as the assembly, is designed for use from -65 to +400 °F and at 125 psig nominal operating pressure. AS1650 was not designed for the new certification requirements for flammable leakage zones and fuel tanks for lightning protection and assembly redundancy. As such, their use and installation may require additional efforts and equipment to support new FAA CFR compliance. The AS7510 flexible coupling should be the preferred coupling for use in flammable leakage zones and fuel tanks that require service life and functionality for lightning protection and part redundancy
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
This Aerospace Recommended Practice (ARP) provides general requirements for a generic, integrated rudder and brake pedal unit, incorporating a passive force-feel system that could be used for fixed-wing fly-by wire transport and business aircraft. This ARP addresses the following: The functions to be implemented The mechanical interconnection between captain and F/O station The geometric and mechanical characteristics The mechanical, electrical, and electronic interfaces The safety and certification requirements
A-6A3 Flight Control and Vehicle Management Systems Cmt
This specification covers the general design, testing, and safety requirements for aircraft tank mounted fuel booster pumps used for engine fuel feed, transfer, and jettison
AE-5B Aircraft and Engine Fuel and Lubricant Sys Components
This SAE Aerospace Standard (AS) defines the requirements for a threadless, flexible, self-bonding coupling assembly which, when installed on machined fixed cavity ferrules, provides a flexible connection for joining tubing and components in aircraft fuel, vent or other systems. This assembled coupling, hereafter referred to as the assembly, and is designed for use from −65 to +400 °F and at 125 psig nominal operating pressure. AS1650 was not designed for the new certification requirements for flammable leakage zones and fuel tanks for lightning protection and assembly redundancy. As such their use and installation may require additional efforts and equipment to support new FAA CFR compliance. The AS7510 flexible coupling should be the preferred coupling for use in flammable leakage zones and fuel tanks that require service life and functionality for lightning protection and part redundancy
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
This SAE Aerospace Recommended Practice (ARP) provides technical design and application information related to the generation, distribution, control, and utilization of aircraft 270 V DC electrical power systems and support equipment. This document also provides references and definitions to permit comparisons of various electrical systems and components
AE-7C Systems
This document establishes techniques for validating that an Aircraft Station Interface (ASI) complies with the interface requirements delineated in MIL-STD-1760B Notice 3. For validation of aircraft designed to MIL-STD-1760A Notice 2 AS4764 Issued 1995-04 applies
AS-1B Aircraft Store Integration Committee
This document establishes techniques for validating that a mission store complies with the interface requirements delineated in MIL-STD-1760
AS-1B Aircraft Store Integration Committee
This document establishes techniques for validating that an aircraft station complies with the interface requirements delineated in MIL-STD-1760
AS-1B Aircraft Store Integration Committee
This aerospace specification defines the requirements for a threadless, flexible, conductive, self-bonding coupling assembly which, when installed on fixed cavity ferrules, provides a flexible, current carrying connection for joining tubing and components in aircraft fuel, vent and other systems. The assembled coupling is designed to provide interchangeability of parts and components between qualified manufacturers for the service life of the aircraft system. The assembled coupling is for use from -65 to +200 °F at nominal operating pressures (125 psig for -08 through -64 and 30 psig for -72 through -88). This aerospace specification is a departure from prior qualification practices for assembled couplings. Prior practice sought to validate this type of assembled coupling design by conducting a sequence of tests on sets of coupling assemblies. There were multiple test sequences and each was conducted on a different set of coupling assemblies. Each of these test sequences challenged a
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
This specification covers flexible couplings for joining tubing with AS5131 Type A beaded ends for use in aircraft fuel and vent systems (see 6.1
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Lightning strikes on automobiles are usually rare, though they can be fatal to occupants and hazardous to electronic control systems. Vehicles’ metal bodies are normally considered to be an effective shield against lightning. Modern body designs, however, often have wide window openings, and plastic body parts have become popular. Lightning can enter the cabin of vehicles through their radio antennas. In the near future, automobiles may be integrated into the electric power grid, which will cause issues related to the smart grid and the vehicle-to-grid concept. Even today, electric vehicles (EVs) and plug-in hybrid vehicles (PHEVs) are charged at home or in parking lots. Such automobiles are no longer isolated from the power grid and thus are subject to electric surges caused by lightning strikes on the power grid. A charging system connected to an EV or PHEV should absorb the surge, but powerful lightning strikes can overwhelm the surge protection and intrude into the electric and
Alkhteeb, Sultan A.MOho, ShigeruNagashima, YukiNishimura, SeisukeShimizu, Hiroyuki
The SPA-10 project, sponsored by U.S. National Science Foundation, is to acquire and qualify a replacement for the retired T-28 “storm penetration” aircraft previously used to acquire meteorological data to enable understanding and modelling of mid-continent thunderstorms. The National Science Foundation selected the Fairchild A-10 (bailed from the U.S. Air Force) as the platform to be adapted to perform the storm penetration mission to altitudes of eleven kilometers, and funded Naval Postgraduate School’s Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) as prime contractor. An expert panel conducted a review of the SPA-10 project in 2014 and recommended a risk analysis addressing hazards to the aircraft and pilots, such as icing, hail, turbulence and lightning. This paper presents the results of the risk analysis performed in response to this need, including recommended mitigations. In general the A-10 aircraft systems and structure were shown to be robust and
Millar, Richard C.Mazzuchi, ThomasJonsson, Haflidi
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