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The mutual aerodynamic influence of road vehicles in close proximity is known to alter significantly the drag performance of the vehicles. This paper presents an extended analysis from a study of two open-access road-vehicle shapes (a DrivAer Notchback model and an AeroSUV Estateback model) in close lateral proximity with each other, or with other vehicle shapes. Wind-tunnel measurements were conducted for a yaw-angle range of ±10°, for lateral distances representing 75%, 100%, and 125% of a typical highway lane spacing, and for longitudinal distances up to 2 vehicle lengths forward and back. The results of a previous analysis of the data, which examined aerodynamic force measurements only, showed changes in drag coefficient of ±20% or more depending on the relative locations and wind conditions. In this paper, the force-coefficient results reexamined, and surface-pressure measurements are introduced to investigate the sources of the performance changes.

A 10-foot-long fuselage section from a Boeing 737-100 airplane was dropped from a height of 14 feet generating a final impact velocity of 30 feet per second. The fuselage section was configured to simulate the load density at the maximum takeoff weight condition. The final weight of 8870 pounds included cabin seats, dummy occupants, overhead stowage bins with contents, and cargo compartment luggage. The fuselage section was instrumented with strain gages, accelerometers, and high-speed cameras. The fuselage sustained severe deformation of the cargo compartment. The luggage influenced the manner in which the fuselage crushed, affecting the gravitational (g) forces experienced by the test section. The seat tracks experienced 15 g's vertical deceleration. Although numerous fuselage structural members fractured during the test, a habitable environment was maintained for the occupants, and the impact was considered survivable.

The SAE G-27 committee was tasked by ICAO to develop a performance-based packaging standard for lithium batteries transported as cargo on aircraft. The standard details test criteria to qualify packages of lithium batteries & cells for transportation as cargo on-board passenger aircraft. Lithium batteries and cells have been prohibited from shipment as cargo on passenger aircraft since 2016. This paper summarizes the results of the tests conducted by Transport Canada and National Research Council Canada to support the development of this standard with evidence-based recommendations. It includes a description of the test specimens, the test set up, instrumentation used, and test procedures following the standard as drafted to date. The study considered several lithium-ion battery and cell chemistries that were tested under various proposed testing scenarios in the draft standard.

Many of the certification regulations in 14 CFR Part 25 are by design, broad and as such, can be subject to large differences in the interpretation of what constitutes adequate compliance. Advisory Circulars (AC's) were developed for many of the regulations to assist industry, as well as certification personnel, with what is considered an acceptable, but not the only means, of compliance. However, there are many regulations where no advisory material is available. In these cases, the “acceptable means” of compliance can vary to a greater degree among the various aircraft certification offices. This difficulty is aggravated as new applicants and regulatory personnel enter the certification field. Recent discussions and interpretations on the usage of an avionic unit's mean time between failure or MTBF for its detectable faults as the basic repair rate for undetected or latent faults, is a subject area where no significant advisory material exists.

The FAA Office of Aviation Medicine has developed, delivered, and tested a variety of training systems over the past decade. The systems, their design, and guidance materials are directly transferable to the aviation industry at no cost. This paper describes the many training systems that are available.

Fuel savings from truck platooning are generally attributed to an aerodynamic drag-reduction phenomena associated with close-proximity driving. The current paper is the third in a series of papers documenting track testing of a two-truck platoon with a Cooperative Adaptive Cruise Control (CACC) system where fuel savings and aerodynamics measurements were performed simultaneously. Constant-speed road-load measurements from instrumented driveshafts and on-board wind anemometry were combined with vehicle measurements to calculate the aerodynamic drag-area of the vehicles. The drag-area results are presented for each vehicle in the two-truck platoon, and the corresponding drag-area reductions are shown for a variety of conditions: gap separation distances (9 m to 87 m), lateral offsets (up to 1.3 m), dry-van and flatbed trailers, and in the presence of surrounding traffic.

In an effort to support Phase 2 of Greenhouse Gas Regulations for Heavy-Duty Vehicles in the United States, a track-based test program was jointly supported by Transport Canada (TC), Environment and Climate Change Canada (ECCC), the U.S. Environmental Protection Agency (EPA), and the National Research Council Canada (NRC) to assess aerodynamic evaluation methodologies proposed by the EPA and to provide a site-verification exercise against a previous test campaign with the same vehicle. Coast-down tests were conducted with a modern aerodynamic tractor matched to a conventional 16.2 m (53 ft) dry-van trailer, and outfitted with two drag reduction technologies. Enhanced wind-measurement instrumentation was introduced, consisting of a vehicle-mounted fast-response pressure probe and track-side sonic anemometers that, when used in combination, provided improved reliability for the measurements of wind conditions experienced by the vehicle.

Selected ferritic stainless steel sheets for exhaust applications were tested under thermo-mechanical fatigue (TMF) condition in the temperature range of 400-800 °C with partial constraint. Straight welded tubes were used as the testing coupons to withstand large compression without buckling, and to understand the effect of welding as well. Repeated tests confirmed the observed failure scenario for each material type. The hysteresis loop behaviors were also simulated using the mechanism-based integrated creep and fatigue theory (ICFT) model. Although more development work is needed, for quick material screening purpose this type of testing could be a very cost effective solution for materials and tube weld development for exhaust applications.

Strain controlled thermo-mechanical fatigue (TMF) tests were conducted on a high Silicon ductile cast iron (SiMo) as the baseline material and a similar SiMo cast iron with aluminum addition (SiMoAl). The much improved fatigue life with aluminum addition is analyzed using the integrated creep-fatigue theory (ICFT) in combination with the metallurgical analysis on the tested coupons. Addition of about 3 wt.% Aluminum significantly improved TMF life of the SiMo cast iron. The results are explained by elimination of brittleness at middle temperature range, the higher flow stress, lower creep rate and higher oxidation resistance from Al addition.

Road vehicles have been shown to experience measurable changes in aerodynamic performance when travelling in everyday safe-distance driving conditions, with a major contributor being the lower effective wind speed associated with the wakes from forward vehicles. Using a novel traffic-wake-generator system, a comprehensive test program was undertaken to examine the influence of traffic wakes on the aerodynamic performance of heavy-duty vehicles (HDVs). The experiments were conducted in a large wind tunnel with four primary variants of a high-fidelity 30%-scale tractor-trailer model. Three high-roof-tractor models (conventional North-American sleeper-cab and day-cab, and a zero-emissions-cab style) paired with a standard dry-van trailer were tested, along with a low-roof day-cab tractor paired with a flat-bed trailer.

The rapid growth in digital computer technology and display systems has impacted most aerospace disciplines. The designer manufacturer operator and even airplane passengers are all affected by this technology boom. The FAA in its role of certifying new aerospace products is no exception. This paper will emphasize the changing methodology of the FAA certification process with some specific examples of recent flight test programs.

One of the major sources of chlorine in automobiles is polyvinyl chloride (PVC). When old discarded automobiles enter the recycling loop by far the largest percent of this material finds its way into the solid waste fraction known as automobile shredder residue (ASR). While the majority of this waste is currently disposed of in landfills new processes are currently being evaluated to recycle and recover the valuable resources contained in this solid waste. Pyrolysis, the thermal cracking of the polymeric materials present in ASR, to recover the petrochemical hydrocarbons is one such technology which is receiving attention. However, like combustion with energy recovery, the pyrolysis process is receiving close scrutiny in terms of its environmental impact. These concerns have centered around the fate of the chlorine and the heavy metals present in the ASR.

As a part of its International Aging Aircraft Research Program, the Federal Aviation Administration is establishing a state-of-the-art Flight Loads Data Collection Program. Data collected in this program will provide the necessary mission profiles and load spectra information to characterize typical fleet service usage for the regional/commuter service life extension program. In addition, these data are applicable for both a safe life fatigue analysis and a damage tolerance fracture mechanics analysis. This paper describes the FAA approach and schedule for instrumenting fleet service aircraft, and the data reduction process.

The 9-meter wind tunnel of the National Research Council (NRC) of Canada is equipped with a boundary layer suction system, center belt and wheel rollers to simulate ground motion relative to test articles. Although these systems were originally commissioned for testing of full-scale automotive models, they are appropriately sized for ground simulation with half-scale tractor-trailer combinations. The size of the tunnel presents an opportunity to test half-scale commercial vehicles at full-scale Reynolds numbers with a model that occupies 3% of the test section cross-sectional area. This study looks at the effects of ground simulation on the force and pressure data of a half-scale model with rotating tractor wheels. A series of model changes, typical of a drag reduction program, were undertaken and each configuration was tested with both a fixed floor and with full-ground simulation to evaluate the effects of this technology on the total and incremental drag coefficients.

Wind tunnel tests were performed on an 8.9-percent scale semispan wing in the Wichita State University 7x10-foot wind tunnel with simulated ice accretion shapes. Simulated ice shapes from large-droplet clouds, simple-geometry ice horn shapes, and simple-geometry spanwise ridge shapes typical of runback icing were tested. Three Reynolds number and Mach number combinations were tested over a range of angles of attack. Aerodynamic forces and moments were acquired from the tunnel balance and surface pressures and oil flow visualizations were acquired. This research supplements the Swept Wing Icing Program recently concluded by NASA, FAA, ONERA, and their partners by testing new ice shapes on the same wind tunnel model. Additional surface roughness was added to simulate large-droplet ice accretion aft of the highly three-dimensional primary ice shape, and it had little effect on the wing aerodynamic performance.

The present regulatory tool for assessment of aircraft smoke emission, the Ringelmann Chart, is described; some of the shortcomings associated with its use for aircraft are discussed; research and development efforts to improve on this system are described. The gaseous pollutants, their relative importance in an airport area and research underway or needed is also discussed.

This paper describes the recently established Commercial Aviation Alternative Fuel Initiative (CAAFI), including its goals and objectives, as well as presents an alternate fuel roadmap that was originally generated by industry and refined by the CAAFI stakeholders. CAAFI is designed to coordinate the development and commercialization of “drop-in” alternate fuels (i.e. fuels that can directly supplement or replace crude oil derived jet fuels), as well as exploring the long-term potential of other fuel options. The ultimate goal is to ensure an affordable and stable supply of environmentally progressive aviation fuels that will enable continued growth of commercial aviation. This initiative is organized into four sub-groups: Research and Development (R&D), certification, environment, and economics & business. The R&D group seeks to identify promising new drop-in alternate fuels, and to foster coordination of development efforts.

The Federal Aviation Administration has placed increasing emphasis on modern information systems to achieve safety improvements. The ASAS (Aviation Safety Analysis System) is a comprehensive new system to upgrade significantly the agency's ability to collect process and disseminate safety-related information.

In view of the fact that future generations of derivative or new aircraft will be faced with problems of increasing operating efficiency, new and more advanced technology will have to be introduced. To this end, the Federal Aviation Administration has been examining the certification question and has concluded that simulation may be increasingly important in the future certification activities. Through a contract with Lockheed Aircraft Company, the FAA will be able to review past use of industrial simulation in connection with certification.

During the past year, a novel turbulence generation system has been commissioned in the National Research Council (NRC) 9 m Wind Tunnel. This system, called the Road Turbulence System was developed to simulate with high fidelity the turbulence experienced by a heavy duty vehicle on the road at a geometrical scale of 30%. The turbulence characteristics that it can simulate were defined based on an extensive field measurement campaign on Canadian roads for various conditions (heavy and light traffic, topography, exposure) at heights above ground relevant not only for heavy duty vehicles but also for light duty vehicles. In an effort to improve continually the simulation of the road conditions for aerodynamic evaluations of ground vehicles, a study was carried out at NRC to define the applicability of the Road Turbulence System to aerodynamic testing of full-scale light duty vehicles.