Browse Topic: Personnel
A 4-rotor uninhabited air vehicle is described, with a primary mission of supporting personnel fighting wildfires. The paper demonstrates the use of technical design tools for a small Uninhabited Aircraft System (sUAS). A description of the design process is provided, including developing requirements, identifying constraints, the software tools employed, and examination of results. The vehicle is capable of delivering more than 20 kg of supplies to a delivery point 10 nm away while penetrating 30 kt winds. The sized vehicle is transportable in a medium-duty pickup truck and can be picked up and moved for ground handling by one or two individuals. The vehicle information will be publicly released for NDARC software users. Future work will examine other requirements, such as maneuvering and gust rejection.
This study investigates the evolution of axial and radial velocities in the downwash-outwash region of a counter-rotating coaxial rotor hovering in-ground effect (IGE). The presence of the ground deflects the axial flow of the rotor wake radially outward, with mean radial velocities reaching approximately 2Vh along the ground. Based on the observed velocity profiles, the wake was classified into three distinct regions: the downwash region characterized by maximum wake contraction, the transition region where flow turns from axial to radial, and the outwash region exhibiting wall jet behavior. Results show that increasing inter-rotor spacing d/R and rotor height above ground (z/R)l extends the downwash and transition regions, delaying the onset of radial outwash. Aerodynamic loads on personnel were estimated, showing maximum mean forces and moments of 120N and 120Nm, remaining within safety thresholds for untrained personnel. However, the loads exceeded these limits for heavy-category helicopters with higher disk loading. Instantaneous velocities revealed unsteady behavior driven by tip vortex convection, with peak velocities reaching 2.8Vh and peak loads approximately 50% higher than mean values, as identified using the 98th percentile approach. Frequency analysis confirmed that fluctuations at the rotor frequency dominated the unsteadiness in the rotor wake. These findings provide critical insights for safe rotorcraft operation near ground surfaces and contribute to informed vertiport design and personnel safety guidelines.
Illustrations used here are not intended to include all existing industrial or agricultural machines, or to be exactly descriptive of any particular machine. They have been picked to describe the principles to be used in applying this standard.
On August 1, 1963, the first two Canadian Sea King helicopters arrived at their new home station, Shearwater, Nova Scotia and joined the Royal Canadian Navy. On Saturday, December 1, 2018, three Canadian Sea King helicopters, now part of the Royal Canadian Air Force, made their final flight over their home station at Patricia Bay, British Columbia. This paper outlines some of the highlights of the intervening 55 years with particular emphasis on procurement and fleet introduction, the helicopter's rapid change of roles from dedicated anti-submarine warfare helicopter to a general-purpose surveillance platform for the First Gulf War and finally, the truly amazing accomplishments of the Canadian Sea Kings in the year 2010. It is worth bearing in mind that although the personnel may have changed and the roles and equipment of the aircraft have been modified, the requirement to provide ‘Wings for the Fleet’ has remained constant over the years.
ABSTRACT Resin pre-impregnated fiber reinforced plastic components are integral to the advancement of rotorcraft due to their highly customizable configuration, outstanding dynamic properties, and light weight. The complexity of their fabrication introduces numerous manufacturing challenges; chief among these is the internal location of individual plies of material. Industry standard solutions are commensurately complicated and require highly specialized equipment and personnel. In order to mitigate this, the Sikorsky-Boeing SB>1 DEFIANT™ Technology Demonstrator team developed the use of additively manufactured (AM) ply locating templates as a simple, low cost alternative. An AM template eliminates many of the issues associated with industry standard ply location techniques and tools. They are elegantly simple to use while being extremely ergonomic; they are extremely cost effective, and require no capital equipment to support them; and they are flexible and quick to implement.
ABSTRACT This paper presents a new method for the detection and prognosis of sensor and wiring failures in rotorcraft and aircraft. Our approach, called the Abnormal Derivative Frequency (ADF), is able to detect sensor and wiring failures in the challenging setting where sensor readings do not exceed pre-determined thresholds and thus do not trigger a rotorcraft's onboard diagnostics algorithms to issue warnings, such as fault messages. The ADF is straightforward to compute, which makes it amenable to implementation in onboard mission processor software. We demonstrate the effectiveness of our method on field data collected from hundreds of Apache rotorcraft. We show that the ADF is able to reliably detect the onset of sensor and wiring problems well before they are caught by onboard diagnostic algorithms and maintenance personnel or crew members. Our approach has the added benefit of helping to distinguish between sensor/wiring problems and actual component failures, thus reducing trouble-shooting time and maintenance costs.
ABSTRACT The goals of sustainable manufacturing, as articulated by Organization for Economic Co-operation and Development (OECD), are to reduce the intensity of material use, energy consumption, emissions and unwanted by-products - while maintaining or improving the value of products to society and to organizations. Benefits that can be achieved through this practice include improved working conditions, public image, staff morale, customer loyalty, brand value, profits, sales turnover, product performance, reduction in waste generation and staying ahead of regulatory concerns. Achieving such goals begins early in the product design phase with consideration toward materials used and processes invoked in manufacturing. Ultimately, a full sustainability assessment must include the product's End-of-life (EOL) impact, factoring environmental impacts of landfill and recycling emissions. This paper focuses on using an End-Of-Life impact assessment for a set of materials and processes commonly used in the aerospace industry. Available data and best practices are used to forecast the final EOL impact of an aerospace product for a given set of materials and processes. The approach is able to quantify costs incurred to advance manufacturing processes and can be used to inform top management on sustainability decisions. The approach could be extended to assess the complete aircraft, including its Beginning of Life.
ABSTRACT Rotorcraft OEM's are increasingly benefitting from the safety of health monitoring systems. At the same time, flight parameter analysis is improving operational and maintenance efficiency. Bell's latest development in health and usage monitoring system (HUMS) is called MissionLink® which presents flight data to customers and to Bell customer support and engineering personnel. MissionLink® was created using a customer-centric development process. MissionLink® supports a variety of aircraft and HUMS devices and is fully automated - from data upload to its web-based presentation. Analysis features include vibration alerts, operator defined limits, watch lists, and trend detection. Usage monitoring and analysis of the data are provided via a tiered methodology that recognizes flight characteristics over time for useful operator feedback.
ABSTRACT Helicopter Sling Load (HSL) missions pose significant safety risks to the ground personnel involved with hooking up payloads to the helicopter. The goal of this project is to develop a materiel solution to increase the safety of an HSL hookup team by eliminating the personnel subjected to the hazards of the HSL mission. The research reviewed in this paper discusses two concepts that were evaluated for HSL auto hookup capabilities: a grapple hook design with three spring articulating arms and a system that used a cone on cone design. For this project, flight evaluations were conducted on prototypes of the two concepts with the following Army helicopters: LUH-72 Lakota, UH-60 Blackhawk, and CH-47 Chinook. There are two modes of HSL that were looked at for this project: single point sling load and dual point sling loads.
ABSTRACT This paper provides insight into the methods used by U.S. Army Aviation Engineering Directorate personnel to assess airworthiness impacts due to changes in loads, usage, or strength, and resulting effects on calculated safe-life retirement times. Statistical analysis of system reliability for overflight of the safe-life time for components with assumed failure distributions forms the mathematical basis for the method. Topics include failure rate, baseline failure rate, percent change in system level risk, immeasurable risk, and mathematical relationships between each. Results include figures to aid in visualization and tables to enable the reader to check an implementation of the method for specific examples. The paper presents the results of analysis used to derive Weibull slope parameters based on recently developed fatigue reliability methods and available mission loads spectra. Finally, the paper presents a new method to establish life factors required to convert retirement intervals with a delta failure rate (for an airworthiness impact) into retirement intervals with immeasurable risk. Modified life factors address special cases of incompatible confidence and analysis uncertainty.
ABSTRACT The Army Aviation Hall of Fame states that "No individual has had a greater impact on the Army and the Aviation Branch" than General Richard Cody. After receiving his commission in 1972 at West Point, Cody served with distinction for 36 years until retiring as the Army's 31st Vice Chief of Staff in 2008. While still a Lieutenant Colonel, in 1991 he led his Apache battalion into Iraq to fire the first shots of Operation DESERT STORM, eliminating critical enemy radar sites before the air war campaign even began. In the years following September 11, 2001, as Deputy Chief of Staff for Operations (G-3/5/7) and then as Vice Chief of Staff, his efforts led to the most sweeping transformation the Army and the Aviation Branch had ever seen. An ace special operations pilot and brilliant military mastermind, General Cody may best be remembered, however, as the well-loved "Soldiers' General."
Motion blur results when a moving edge travels across a display, such as a liquid crystal display (LCD), that has limited temporal response. It is important to be able to quantify this effect in visual terms. The techniques described in this work provide methods for estimating the strength of the motion blur artifact in perceptual units of JNDs (just noticeable differences).
ABSTRACT The Institute for Defense Analyses (IDA) provided assistance to the U.S. Army Training and Doctrine Command (TRADOC) Analysis Center (TRAC) in their Brownout Rotorcraft Enhancement System (BORES) Analysis of Alternatives (AoA). IDA conducted a thorough literature search and documented the historical (2000-2013) rotorcraft brownout incidents, loss of personnel and equipment, and associated equipment costs. In addition, IDA considered future estimates of possible brownout mishap mitigation along with estimated “breakeven” costs for the BORES sensor integration on the Army H-60 and H-47 series aircraft. This is the cost above which new sensors would be more than the savings associated with preventing future rotorcraft brownout incidents. These helped inform decision makers on the overall cost-effectiveness of the currently envisioned BORES as a function of the future force structure, flying hour (FH) rates, and operating environments.
ABSTRACT Improvement of cargo tie-down systems is of utmost importance to help ensure rotorcraft crew safety in the event of a hard but survivable crash or hard landing. To this end, various load-limiting, energy-absorbing devices, placed in-line with conventional tie-down hardware such as straps and chains, have been evaluated for their ability to prevent the complete failure of a tie-down and the unconstrained movement of cargo in the vicinity of nearby personnel and structure during a high-acceleration event. The current investigation aims to further this line of exploration by evaluating the performance of textile-based energy absorbing devices in well-controlled laboratory experiments using a horizontal sled and in field experiments using crash-tests of CH-46 hulks. Textile-based energy absorbers of a capacity suitable for rotorcraft tie-down systems are shown to behave as designed in both types of experiments. The devices prevented the failure of a simulated tie-down point in accelerative environments that failed the tie down point in the absence of an energy absorber.
Items per page:
50
1 – 50 of 292