Browse Topic: Fleets
The Sikorsky S-92® helicopter fleet, representing more than 300 aircraft and 2.6 million flight hours, is relied upon to support a large range of important missions across the globe. In previous efforts, a high-fidelity CFD-CSD based full-aircraft simulation methodology, co-simulated with production FCS, was developed and applied to model both coaxial aircraft and single main/tail rotor configurations (Refs. 1-5). The CFD solver is based on the CREATE™-AV HELIOS toolset (Ref. 6) and the CSD solver is based on Rotorcraft Comprehensive Analysis System (RCAS) (Ref. 7). The current paper further correlated the CoSim methodology (Ref. 1) with the S-92® helicopter flight-test database at both hover, cruise and edge-of-envelope maneuver flight conditions. The consistent correlations for flight dynamics, static and fatigue component loads at conditions across the flight envelope demonstrate the reliable predictive capability of the high-fidelity CoSim methodology to be-used as a virtual digital flight test and to support advanced design at early stage.
Vertical Take-Off and Landing (VTOL) aircraft introduce complex monitoring challenges due to distributed propulsion, lightweight structures, and variable operating conditions. This paper presents advanced Frequency and Orders domain techniques that repurpose existing flight control, propulsion, and structural sensor data to enhance observability without additional instrumentation. By transforming vibration, acoustic, and electrical signals into frequency and order domains, the approach enables detection of harmonics, resonance, and fault signatures tied to rotor dynamics, supporting adaptive control and predictive maintenance. Beyond rotor systems, these techniques are equally effective for monitoring electric motor health, gearbox wear, bearing degradation, and structural coupling effects in composite airframes. They also provide insight into power electronics and thermal management systems by identifying spectral anomalies linked to electrical imbalance or cooling inefficiencies. Aggregated fleet data strengthens prognostic capabilities, enabling early detection of systemic issues and trend analysis. Applications include mitigating ground resonance and modal instabilities, as well as improving reliability of propulsion and structural subsystems. Integration into avionics emphasizes computational efficiency, scalability, and compliance with standards such as DO-160 [1], DO-178 [2], ARP4761 [3] and ARP4764 [4]. Simulation and bench testing confirm feasibility, demonstrating potential to enhance safety, reliability, and lifecycle cost for next-generation urban air mobility platforms.
This paper discusses uncrewed aerial vehicles (UAVs) that can have additional applications beyond their respective civilian, industry, or military applications. The increasing popular electric UAVs in advanced air mobility (AAM) and urban air mobility (UAM) networks can be utilized to increase the efficiency and impact of emergency response in both urban and remote settings. The paper will explore the design considerations and requirements for these dual-use vehicles for specific public good missions, while presenting a survey of additional public good missions that could significantly benefit from additional ready-to-go drones. Additionally, this paper aims to explore the logistics required to implement a system for incorporating civilian, industrial, and military drones into a reserve fleet for emergency and disaster relief efforts.
The H-60 Black Hawk remains a cornerstone of U.S. Army Aviation, but its legacy avionics architecture presents modernization challenges. To ensure long-term operational relevance and interoperability with future platforms like the Future Long Range Assault Aircraft (FLRAA), the Army is implementing a Modular Open Systems Approach (MOSA). This strategy facilitates rapid technology integration, enhances sustainment efficiency, and mitigates obsolescence. The Army's MOSA adoption aligns with regulatory mandates such as the National Defense Authorization Act and Department of Defense (DoD) acquisition policies, ensuring modularity, scalability, and interoperability across aviation systems. The application of modern open standards, such as the Future Airborne Capability Environment (FACE®), within the Black Hawk supports software reuse and hardware commonality, reducing lifecycle costs and vendor lock. A phased modernization approach, including a Digital Backbone architecture supported by Model-Based Systems Engineering (MBSE), will streamline future avionics upgrades while maintaining compatibility with existing and future fleet assets. This transformation positions the Black Hawk for sustained operational effectiveness in multi-domain operations, reinforcing the Army's aviation modernization objectives.
On July 19, 1990, Senator Danial Inouye chaired a subcommittee to address the fate of the USMC V-22 Osprey program. Prior to this meeting, Secretary of Defense Dick Cheney, at a time of increasing fiscal constraints on defense spending, in a controversial decision, terminated the V-22tilt rotor aircraft program. However, it was resurrected by Congress. Proponents of the V-22claimed the aircraft costs were justified since it represented revolutionary technology with long-term benefits to military and civil aviation. Therefore, a study was authorized through the office of the Honorable David Chu, then Assistant Secretary of Defense for Program Analysis and Evaluation. The Institute for Defense Analyses (IDA), a Federally Funded Research and Development Center (FFRDC), was tasked to conduct the analyses. IDA conducts studies and analyses for the Office of the Secretary of Defense, the Joint Staff, the unified commands, and the Defense agencies. IDA was specifically tasked to conduct an "Assessment of Alternatives for theV-22 Assault Aircraft Program." The study was led by Dr. L. Dean Simmons and supported by Professor Alfred Gessow and Kaydon A. Stanzione who served as Air Vehicle Technical Expert. The focus was on two key considerations that related to the cost of the aircraft: 1) the overall cost effectiveness of the alternative fleets measured over a 20-year period that was used as the principal basis for conclusions, and 2) the difference in the near-term costs for the alternative fleets.
The subject of this paper is the conceptual development of two new configurations for HEMS Operations as a new fleet concept for the European theater. Previous studies showed an increase of the required flight range for an emergency patient transport. But in conjunction with an average share of less than 30% of the flights actually with the patient. In the most rescue missions an emergency physician is transported to the scene, the patients further transport is conducted on-road by an ambulance. Considering an improved flight performance, the first DLR design study revealed a growth of the maximum take-off mass of the primary rescue helicopter of 32%. That makes the rescue helicopter inefficient for the transport of only the emergency physician. Consequently, if an ambulance is already at the scene, an emergency doctor shuttle is the sensible approach. The requirements for such a configuration are developed from a feasibility study lead by the ADAC Air Rescue (ADAC Luftrettung), considering the design of a progressive multirotor configuration. This paper presents the state of the design process for both rescue configurations. This includes the definition of the external configuration, cabin design, propulsion architecture, aerodynamics, flight performance, wind tunnel test, and structural considerations.
This paper presents a new approach, variant of the Direct Load Recognition (DLR) methodology, to estimate the main rotor (MR) pitch-link load on customer flights. The original DLR methodology is based on the combination of a harmonic decomposition and the use of Machine Learning algorithms. The DLR variant replaces the harmonic decomposition by a wavelet decomposition. The application of this paper consists in two parts. First, the comparison between the original DLR and DLR variant on prototype flight test data. Two results are highlighted in this part. The capacity of representation of the pitch-link load is better for the wavelet decomposition. The modelling of its coefficients enables to slightly improve the pitch-link load estimation, especially on the high load values having more impact on the fatigue computation. This first part allows to study the feasibility of the DLR variant to estimate the pitch-link load. The second part of this paper focuses on the application of the pitch-link load estimator built with DLR variant on the H175 fleet. From the estimated MR pitch-link load, the MR pitch horn damage is derived and compared to the Design Usage Spectrum (DUS), used today for the certification. The damage of all the studied customer aircraft is well below the DUS, showing a potential gain in component life time. The results of this paper manifest the advantage of the DLR methodology, and more precisely DLR variant methodology, for predictive maintenance on the MR pitch horn, that is to adapt the maintenance to the aircraft usage.
Previous work documented the use of IVHMS data on the U.S. Army's fleet of UH-60 Black Hawk helicopters to update the fatigue lives of six specific components on the A/L and M models. This paper documents a significant expansion of the level of data applied to the usage spectrum, as well as applying it to all components on the aircraft. As a design spectrum for the yet to be fielded Improved Turbine Engine (ITE) equipped UH-60M, changes due to new engine capability needed to be addressed. The new spectrum has been developed and is being used for planning of flight testing. The spectrum along with flight test loads will be used to generate fatigue lives for the new aircraft. Once deployed for several years the spectrum will be reviewed to determine if any changes are needed. This work highlights what the Army considers to be the most significant issues when applying monitored usage to critical fatigue components, and rationale for dealing with issues such as insufficient data for various purposes.
Launch, recovery, and deck handling operations are among the most challenging tasks in the deployment of fleet piloted and unpiloted air vehicles on board of air capable ships. In today's long-lead acquisition process, some existing devices are installed on new ship platforms for which the air vehicle was not initially designed. As part of the Navy deployment process, a ship suitability assessment is conducted in the form of Dynamic Interface (DI) testing. DI testing evaluates all aspects of shipboard helicopter including suitability, compatibility, adequacy, effectiveness, safety of air vehicle shipboard Flying Qualities and Performance (FQ&P), aviation support facilities and procedures for all ship-based aircraft types. With monohulled rudder/screws steered legacy vessels, certain seakeeping and turbulent boundary properties have open-ocean performance similarities. When faced with a deployment target ship producing different ship properties, a systematic approach to adapt to the new environmental condition is devised. A significant example involves the deployment of air vehicles (both piloted and unpiloted) on-board LCS class vessels where large, unexpected roll oscillations, coupling with rapid motions of the stern, are recorded. These unusual deck responses have been traced to shipboard operational characteristics which do not relate to the seaway alone. The implications for air vehicle operations encountering seemingly random large motions further underscores the need for an accurate definition of the ship's dynamics and, possibly, refined models able to predict steep motions anticipating the onset of excessive movements. In this paper we describe a new instrumentation with the goal to predict ship motions conditions with sufficient forecasted time (over a minute) to launch, recover and complete other motion sensitive tasks regardless of the seaway. The fundamental concept is to measure remote sea surface profiles to predict the future wave forces acting upon a vessel as a function of the approaching air vehicle. The final objective is to expand ship operating deck limits to approximately Sea State 6+. This will allow the air's vehicle operator to have a more complete deck information and ship behavior. This article describes the common test procedures being developed at Fincantieri to define the deck behavior with the least air vehicle modifications. Enhanced dynamic interface testing is designed to better understand how the new ship classes affect the deck environment. The enhanced trial methodology test results clearly characterize essential aspects of the ship responses to the maritime climate and its impacts on air vehicle launch and recovery.
This paper presents a framework with associated concepts to define a method of compliance for the failure rate requirements of the Army Military Airworthiness Certification Criteria (AMACC), Chapter 5, for fleet qualification and first flight. The fleet failure rate requirement is paraphrased as less than one structural failure in 20 million flight hours at 95% confidence and applies specifically to fatigue failure of primary structural elements (PSEs). This method of compliance assumes a reliability model sufficient to support an analytical failure rate that bounds the uncertainty arising from practical constraints of an aircraft qualification program and aims to optimize the competing objectives of safety of flight and operational capability. The requirements as defined verify that the aircraft system will perform as intended for a specified fleet life and flight test program duration and serve as the analytical basis for the assessment of emergent issues identified throughout the product life cycle.
Corrosion occurs in diverse environments mainly on metallic parts. Helicopters are made of a huge percentage of metallic parts and need to have several maintenance steps to guarantee its functioning and its durability. The military helicopters are flying in different kinds of environment, which cover large spectrum of severity of the atmospheric corrosion [1]. In maritime conditions, the most influencing factor is the Time of Wetness, which is a direct result Relative Humidity and Salt loading. The main material used for aircraft and that is suffering from corrosion is aluminium. There are plenty of data to follow the corrosion as a function of the environmental conditions, mainly on the sensitivity with sodium chloride, Relative Humidity, film thickness, etc... [2][3]. The maintenance efficiency on helicopters is dependent on the environmental severity. The U.S. armed forces estimate $10.2 billion in corrosion costs for their aviation and missile fleets during 2016 [4] [5] [6]. The aim of the present analysis consists of defining the Condition Based Maintenance related to corrosion risk to better apply a maintenance program when it is really needed.
For the last few decades, Canada's National Research Council (NRC) has been at the forefront in analyzing dynamic systems and developing tools to construct aircraft models based on flight test data. With a fixed and rotary-wing aircraft fleet available, NRC has the capability to perform leading edge R&D System Identification (SI); this worldleading SI technology has been developed and has assisted industry partners, Department of National Defense (DND), and various universities in aircraft simulation and development. As a result, NRC has gained extensive experience in modeling aircraft using SI techniques. In collaboration with CAE, this paper demonstrates the acceleration of the NRC's current flight modeling techniques, highlighting recent advances in Artificial Intelligence (AI) and Machine Learning (ML). A new Bayesian ML software is being developed to identify a 6 degrees of freedom (6-DoF) quasisteady model using simulated flight test data. To achieve this, data from the CAE Sample electric Vertical Take-Off and Landing (eVTOL) simulation platform vehicle during hover maneuvers is utilized. Additionally, this paper presents results on extending the model to include rotor dynamics using the classical SI approach for comparison purposes. In summary, all methods provide a high-fidelity model; with the higher model structure, the vertical acceleration match was noticeably better.
As military organizations internationally assess life extension and replacement actions for current legacy helicopter fleets and next generation rotorcraft are under development, novel rotor system technologies are required to fulfill challenging low-speed and high-speed flight envelopes and mission requirements. Proposed by the Department of National Defense (DND) and in collaboration with the National Research Council of Canada (NRC), a TTCP AER CP13A.1 Collaborative Project (CP) has been initiated supporting multi-nation development of numerical methods for optimizing and designing next generation main rotor blades. Four NRC laboratories collaborated to assemble a data set comprising design, performance, aerodynamics, structures, dynamics, and flight sciences elements. Acquired through research and testing, this information provides reference, technical, and engineering knowledge to support aero-structural model definition, model output validation, and the numerical optimization process development.
Applications of Unmanned Aerial Vehicles (UAVs) are on the rise. Particularly within the healthcare sector the potential is huge as its cited as the most accepted application. This paper introduces an agent-based simulation to evaluate the network performance of UAV-based logistics networks in healthcare. The simulation is applied to a hypothetical real-world network. During a simulated day, the UAV fleet performs 212 flights, including 97 delivery flights, amounting to 4264 minutes enroute and covering a distance of 5941 kilometers. The analysis reveals average non-idle and mission utilization of 66% and 33%, respectively. The study also calculates annual network costs of EUR 2.23Mn, with a majority of it being direct costs (54.5%). Further sensitivity analysis identifies the biggest influences of battery capacity, C-Rate, and operator-to-UAV ratio on network performance and costs, highlighting these factors as critical for future optimization. Additionally, the benefit of incorporating various different UAV types into the network is only given if each UAV provides a unique value proposition to enhance the network performance.
In the last decade, in order to respond to the emerging market of unmanned applications, Airbus Helicopters has developed a generic Flight Control System (FCS) for heavy unmanned helicopters. This paper describes the development of this system from the applicable high-level requirements to the design of the redundant fail safe-operative architecture and the flight modes. A focus is made on two specific flight sequences: Automatic Take-Off and Landing from ship deck which is one of the most complex maneuvers for a drone and 4D navigation (including relative to a target). The system has been brought to a maturity level with more than 100 flight hours in unmanned configuration and a level of Validation & Verification close to a certification. The portability of the developed solution on other helicopters to derive new Unmanned Aircraft Vehicle or Optionally Piloted Vehicle is also addressed thanks to commonalities with FCS that are already in use on the Airbus Helicopters fleet.
A limited flight load survey was performed on a fleet representative UH-60L aircraft flown with various degrees and combinations of dynamically imbalanced blades. Blades selected for this test ranged in both positive and negative severity of pitching moment slope values to substantiate rotor smoothing efficacy and the effect on dynamic component oscillatory loads for dynamically imbalanced blades compared to a baseline of nominally balanced blades. For every component analyzed, greater than 70% of the maneuvers presented showed an increase in structural loads in the unbalanced configuration compared to the baseline balanced blades. Most components and maneuvers that did experience an increase in loads remained non-damaging. However, the damper experienced several maneuvers where an increase in loads may have indicated a change in fatigue lives. Based on a colloquial rule of thumb.
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Since certifying the Bell 505 in December 2016, customers on six continents have received delivery of 250 of these light, single-engine aircraft. In three years the worldwide fleet logged more than 35,000 flight-hours, a testament to the Bell 505's customer experience - not only with the aircraft, but with delivery and service. In getting to the 250th delivery, the paper discusses the efforts taken to meet market demand, provide custom finishing, offer kit integration, and even take on additional envelope expansion. Numerous configurations and kits were made available a short time after initial certification, allowing Bell 505 customers to take full advantage of the aircraft capability in a timely manner. The challenges of meeting market demand and transitioning from low rate production to full rate production requires a team effort and this paper shows how it was done for the 505.
Presently the fatigue lives of MH-60R dynamic components and airframe are based on a usage spectrum developed using pilot surveys. In order to better define the usage spectrum and to extend component and airframe fatigue life, the Health & Usage Spectrum (HUMS) System was installed on the U.S. Navy MH- 60R Rotorcraft. So far 207 aircraft are equipped with the HUMS systems and 121,334 flight hours of good data have been recorded. The regime recognition programs recognize 315 maneuvers, but are consolidated to 94 maneuvers of MH-60R usage spectrum, for which the component measured loads are available. To better define usage spectrum in detail and compute realistic component fatigue life, an additional maneuver of low Angle Of Bank (AOB) from 10 to 25 degrees was added, but the measured component loads were not available at this AOB to implement HUMS. Thus, measured flight loads data of level flight and AOB turns at 30, 45, and 60 degrees were utilized to derive component loads at 20 degrees by spline cubic interpolation technique. The cubic interpolation technique was applied to measured minimum, average, and maximum loads of variation at 10, 30, 45, and 60 degrees to interpolate load at 20 degree. This technique was applied to interpolate loads for pitch control rod, swash-plate, drag damper, shaft bending moments, blade cuff stresses, and flap deflections. The spline interpolation loads correlated with measured available loads of pitch control rod and blade stresses. The probabilistic fleet usage spectrum of various severities was developed using the HUMS recorded data of 121, 334 hours from 179 rotorcraft with and without low AOB usage. It is evident that fatigue life with 20 AOB split is significantly higher for all dynamic components. Thus, to implement HUMS successfully, it is necessary to compute loads that are not available in the original component fatigue life calculations. Further prorates of gross weigh (GW), velocity and altitude based on the HUMS fleet usage should be implemented to extend component fatigue lives.
Attempting to pick through bad weather - becoming disoriented in diminished visibility or striking a wire or obstacle at low altitude - remains one of the major causes of fatal helicopter accidents. It is more common than engine failure, more common than mechanical failures, and more common than systems failures. While some feel the answer involves more tools to enable low-flying helicopters to avoid terrain and obstacles, a better solution is to keep helicopters safely away from terrain and obstacles using instrument flight rules (IFR) when weather conditions demand. For single engine helicopters, which form the largest population of helicopters, this means finding cost effective ways to provide them with safe and practical IFR capability. IFR capability is commonplace in airplanes, even among entry-level and training aircraft. An IFR rating is typically the first rating sought after an airplane pilot receives their license. For helicopters, there is currently not a parallel culture of shifting to the safety of IFR operations when weather demands. The reasons are complex, but a significant factor affecting this culture today is that the entryl evel IFR rotorcraft is generally a twin-turbine-engine helicopter. By the time a helicopter pilot gets to this level of machine, he or she is typically well versed in the "alternate" methods of weather avoidance. Unfortunately, even IFR rated helicopter pilots tend to default to a practice of attempting to fly below the weather using visual flight rules (VFR). Increasing the availability of IFR-capable helicopters by restoring practical, low-cost IFR solutions to single engine rotorcraft is the first step in a process intended to change the rotorcraft safety culture. This paper describes a 5-year effort by associations, industry, and regulators to remove the obstacles to certifying low-cost IFR helicopters. By mid-year 2019, two single-engine helicopters were certified for IFR operations, ending an absence of more than 20 years from the marketplace, but these were newly-manufactured aircraft. The remaining challenge is to apply what has been done in order to allow cost-effective retrofits of IFR capability to the existing fleet of VFR helicopters. The hope is that, with the trail now blazed, others will follow, and we will see even more single-engine rotorcraft with IFR capability and fewer weather-related accidents.
The U.S. Department of Defense has begun the acquisition of the next generation of military rotorcraft, named Future Vertical Lift (FVL), to replace its aging fleet. U.S. Army Futures Command intends to sustain FVL under a new strategy of maintenance free operating periods (MFOP). This study developed a discrete event simulation to evaluate MFOP success given component reliabilities, desired MFOP duration, and operational tempo of a battalion with thirty aircraft. The simulation compared notional FVL aircraft with improved reliability to today's fleet. Results indicated that inherent reliability alone was insufficient to achieve MFOP goals and that prognostics and diagnostics with robust information management are necessary. Sensitivity studies found the recovery effort after an MFOP was linked to the MFOP duration. Recovery downtime was tied to both the duration and operational tempo. Availability and cost improved with moderate gains in MFOP duration by eliminating unnecessary preventive maintenance but overextending the MFOP sacrificed aircraft dependability for marginally greater availability and savings.
The current US DoD has recognized that their asymmetric advantage is eroding1. Adversaries have had over 25 years to counter the US playbook and weapon systems (Ref. [1]). The US Army Future Vertical Lift (FVL) programs have identified several key tenets that their airborne weapon systems need to ensure they maintain asymmetric advantage. (1) New and upgraded mission capabilities of their airborne platforms need to get to the field faster (Ref. [2]). One of the current roadblocks to achieving this is the extensive full-system regression testing that ends up being required when there are mission system changes (Ref. [3]). (2) More competition is needed to help generate "quicker, better, faster" capabilities (Ref. [4]). "Vendor lock" inherent in current system designs hinders the speed at which technology advances (Ref. [4, 5]). (3) Improved portability of mission capability across the FVL and enduring fleet (Ref. [6, 7]). The ability to more easily reuse technology will help maintain advantage by eliminating the time needed to develop platform specific solutions (Ref. [4, 6]). The request for Modular Open System Architecture (MOSA) solutions has been a practice to try to address the items above (Ref. [8]). Most air vehicle and mission system providers are today providing MOSA solutions but the required benefits have not yet been fully realized. MOSA standards as they exist today do a very good job of identifying electronics hardware and software architectures. However, they fall short on physical aircraft integration and consistency in architecture among aircraft systems. Minimizing aircraft wiring and structural modifications, increasing speed to fielding, and portability among multiple systems types are all part of integrating highly MOSA compliant solutions. The US Army FVL programs have required a "digital backbone" (Ref. [7, 9, 10]) to address these integration issues and ensure that they can maintain asymmetric advantage. Unique requirements affecting the digital backbone include: - Power and power distribution (Ref. [9]) - Thermal management (Ref. [9, 11]) - Packaging and installation (Ref. [9]) - Air Vehicle data distribution (Ref. [9]) - Mission System data distribution (Ref. [9]) - Isolation of air vehicle and mission system (Ref. [9]) This paper will provide an introduction to the envisioned digital backbone for US Army, Future Vertical Lift aircraft. The paper will also offer discussion of digital backbone impacts on aircraft and avionics size, weight, power and cost, as well as technology considerations to address interoperability, safety, security, qualification, and accommodations for new, as well as, legacy avionics technology.
A primary factor for the development of military avionics systems is the requirement for a Modular Open System Architecture (MOSA). The US Department of Defense (DoD) is driving MOSA-compliant systems to achieve benefits in cost and flexibility within their procurements. MOSA definitions are examined in light of advances in computing disciplines that open the interfaces necessary for the aircraft operator to update and manage their fleet's Health Awareness Systems (HAS). Opening the relevant HAS interfaces via software configuration toolsets and MOSA building blocks avoids contracting for costly software changes and gives control of the update to the operator. Two business related factors are presented for consideration in developing the best way forward while using MOSA principles to guide development. These factors are (1) Intellectual Property (IP) and (2) the underlying investments companies make to develop IP. The need to routinely update the HAS to incorporate fleet lessons learned is inherent in the system's support. Updates may also reflect new methodologies that deliver the desired system control to the operator. The paper demonstrates a MOSA-compliant architecture via an example. Within the example, efficiencies are driven by an end-to-end Digital Thread that minimizes errors and rework while reducing the overall cost of change for the full platform lifecycle. The approach enables organic operator support, lowering the overall cost of aircraft operations. The design and support of the platform’s Health Awareness System benefits from the application of linked-automation.
The U.S. Army monitors the structural integrity of its rotary-wing aircraft fleet through annual evaluations and reporting via the Airframe Condition Evaluation (ACE) program. ACE evaluations capture the location and character of structural defects for each aircraft, which are then available for trending and detailed analysis by engineers with the U.S. Army Combat Capabilities Development Command Aviation & Missile Center (CCDC AvMC). As analytic methods are increasingly advanced through the digital thread, CCDC AvMC has sought to improve available trending, modeling, and analysis tools beyond status quo to provide higher fidelity visuals to both aid communication with decision makers, and also to reveal structural defect trends which may not otherwise be evident. This paper will detail the development and utility of the ACE Color Mapping Application within the ACE Mapping Module and its impact on product support of U.S. Army aircraft with regard to airframe structural integrity.
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.
Australia has embarked on an extraordinary reform to design, develop and implement a new and contemporary Defence Aviation Safety Framework. The program seeks to establish a single Defence Aviation Safety Authority (DASA) and issue a comprehensive and integrated suite of Defence Aviation Safety Regulation (DASR) for initial and continuing airworthiness, flight operations, air navigation, aerodromes (inclusive of ship-borne heliports) and safety management systems. While reforms of this scale can often be triggered by reviews into major aircraft accidents, such as The Nimrod Review by Charles Haddon-Cave QC in October 2009, Australia initiated the reform when new aircraft fleets were being introduced and at a time of arguably high-levels of aviation safety. The purpose of this paper is therefore to explain the compelling reason for change; providing a twenty-five-year retrospective analysis of Australia’s previous Defence aviation safety framework to give a rich picture of the difficulties faced by increased commercialization from the late 1990s, globalization in the 2000s, and the recent emergence of strict work, health and safety legislation in Australia.
Quantitative Risk Assessment has become essential in rotorcraft safety risk management. Measures of risk include Cumulative Fleet Risk (also called Risk Factor), Risk per Flight, and Risk per Flight Hour. Each measure applies to a different situation and can produce the same or different predictions of future risk. Risk for a large fleet of aircraft might be accurately predicted by Cumulative Fleet Risk, whereas Risk per Flight or Risk per Flight Hour might be best for a small fleet of rotorcraft, a flight test program, or a fleet with low flight hours. Calculating risk per flight hour seems as simple as dividing the number of previous occurrences by the flight hours for the total fleet, but this is appropriate only in the case of random distribution. Most failures that lead to hazards are not random because the failure mechanism has a specific cause. A more appropriate method is to develop the future event forecast using Quantitative Risk Assessment, then divide that by the future fleet hours. The simple division process requires only two numbers and can be completed quickly, but with a possibly inappropriate or misleading result for anything but a random distribution. The approach presented here results in a risk prediction that is appropriate for hazard rates that are increasing, decreasing, or constant, and for non-random distributions, which could prevent misleading or unconservative risk management decisions.
The Army's Future Attack Reconnaissance Aircraft (FARA) program is much bigger than the two ambitious high speed helicopters that Bell and Sikorsky will now get more than $1 billion to build. At least five other major moving pieces must come together on time to turn the final aircraft, whoever makes it, into a working weapon: - a new Improved Turbine Engine built by GE; - helicopter-launched mini-drones called Air Launched Effects (ALE); - a new Long-Range Precision Munition (LRPM), with the Israeli Spike-NLOS as the initial version; - an Integrated Missile Launcher (IML) to launch both the missile and the drones; - and the underlying electronic framework of standards and interfaces to plug it all together, the Modular Open Systems Architecture (MOSA). *Recently, FARA has added a 20mm Gatling Gun being developed by The Advanced Rotorcraft Armament and Protection System (ARAPS) program team at the U.S. Army Combat Capabilities Development Center (CCDC) Armaments Center The Army is "not just focused on the air vehicle, but focused on the weapon system," said Brig. Gen. Walter Rugen, Future Vertical Lift director at Army Futures Command, in a call this morning with reporters. [1] While some have questioned the viability of fielding the FARA in ten years, e.g. by 2028, others have offered reasons on why the plan for a next-gen recon aircraft needs to be accelerated. Who knows how much money will be available to the Army for sustaining its aviation fleet as budget walls close in over the next several years? Trilliondollar deficits have a way of impinging on defense budgets. What is proposed, though, is that the Army compress its development schedule for a new armed recon rotorcraft so that our soldiers begin to be better equipped against the likes of Russia and China somewhere around 2025, rather than after 2030. A whole lot can happen in ten years. We don't need another Army development program to be overtaken by events. (2) However, since the FARA will likely be in service for a half-century or more, it makes sense to conduct rigorous analysis up front to ensure that what is fielded has the capabilities to provide the most value for the warfighter and the taxpayer. Prior to spending billions of dollars and decades producing the FARA aircraft, it is prudent to spend the time to determine what the right solutions should be. Many projects fail when the initial requirements are not well thought out and the ramifications are not clearly understood. To solve the tension between these conflicting desires, designers need to iterate the design sensitivities with operational analysis to show the pros and cons of each attribute, alone and in concert, but ultimately the Army must prioritize its requirements and potentially make hard trade-off decisions.(3) The major objective of this paper is provide a methodology for the necessary understanding of the push and pull of technology readiness and application through trade studies and operational analysis early to avoid disappointments and to minimize FARA slippages and cost increases. This will be accomplished by reviewing Lessons Learned from the AHIP/OH-58D Kiowa Warrior and the LHX/RAH-66 Comanche development programs. While the authors were directly involved in these programs as Army Aviation engineers, managers and senior executives, the major emphasis for this paper will be to address how the government-industry teams brought these programs successfully through initial development. Fortunately, for the AHIP/OH-58D Kiowa Warrior Development Program there are excellent documentation of the government-industry team participation in References 4 and 5. While the authors strongly endorse the lessons learned in these documents, they will have a few of their own. For the LHX/RAH66 Comanche Development Program there is considerably less documentation; however, the authors will provide Army and their lessons learned. It is hoped that this paper and the referenced documents will be read, and the lessons learned by both government and industry involved in the FARA development program.
The first prototype SA340 flew the 7 of April 1967 The first prototype SA340 initially flew with a conventional tail rotor. There are more than 5200 helicopters flying today with this anti-torque concept. The first H160 prototype flew the 13th of June 2015 taking advantages of almost fifty years of continuous improvements in its global aerodynamic definition in the service of safety of customer operations. Three generations of Fenestron®, starting from the first Gazelle design take benefits of shroud improvements, dedicated airfoils and uneven spacing of the blade for external noise reduction. H160 is today the flagship of the Airbus Fenestron® Fleet.
The Canadian Search and Rescue (SAR) CH149 Cormorant helicopter, a variant of the AgustaWestland EH-101, entered service for Canada in 2002, equipped with a Health and Usage Monitoring System (HUMS). While HUMS continue to advance and provide increasingly refined solutions, HUMS-equipped aircraft procured before the maturation of these systems require consideration of novel approaches to maximize the benefit of legacy data. Continued regulatory compliance necessitates ongoing innovation and continuous improvement. On the CH149 Cormorant fleet, this is achieved primarily through the refinement of monitoring methods and the expansion of HUMS data in support of the CH149 fleet and the various methods that have been developed to address the limitations of the available HUMS data. Innovations have included developing novel methods for post-process analysis of HUMS data. These methods are leveraged against known fleet maintenance issues and evaluated for effectiveness.
Shipboard rotorcraft operation places significant demand on pilot workload, which can be compounded by harsh environmental conditions. While prior research into characterizing pilot behavior and aircraft handling qualities during shipboard operations has relied on data from flight tests and manned flight simulations, the present work is focused on analysis of a large dataset of operational helicopter data, detailing both ship and shore landings, in order to improve the understanding of helicopter operations and provide the basis for a data-driven assessment of pilot activity. The operational data was classified into two datasets (shipboard landings and shore-based landings) through an automated analysis of the aircraft state parameters. Each dataset was analyzed to produce aggregate landing approach profiles and aggregate representations of pilot control input to facilitate characterization and comparison of the fleet norms for the two sets of landings. The aggregate landing approach profiles showed clear distinctions between the pilot techniques employed in the ship and shore landings, revealing much more uniformity in the execution of the ship landings. The aggregate pilot control input analysis also exposed striking differences in control input activity, with ship landings characterized by higher magnitude, higher frequency control input. Together, these results not only corroborate prior research into qualitative assessments of pilot workload through time-frequency representations, but they also provide a benchmark against which data from other landings (whether operational, flight test, or manned simulator) may be evaluated to determine the efficacy of training procedures or possible changes in rotorcraft handling qualities, particularly in the shipboard environment.
Safety features introduced in recent rotorcraft designs have not made their way into the bulk of the rotorcraft flying fleets around the world in spite many of them have been firstly introduced many years ago in newly certified platforms. The longevity of the current rotorcraft population has proved to be exceeding all the expectations and forecast that were made when these features were introduced. However the flat trend in accident rates and fatalities verified in these years especially in some sectors is urging the regulators and many other stakeholders to take action. Hence the need to define a method able to establish rational priorities to push the new safety features into the market, by using quantitative and qualitative criteria.
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