Browse Topic: Airworthiness
Civil and military rotorcraft operators desire enhanced capabilities from their vehicles in terms of mission efficiency, effectiveness, productivity, and availability. A critical element of this challenge is associated with providing cold weather availability. Currently, cold weather operations are enabled by regulatory actions leading to Limited Approvals, Qualifications, Clearances, and Restrictions. Cold weather certification (clearance of a new aircraft) and continuing airworthiness (maintaining effectiveness of fielded aircraft) are data driven processes. This work provides guidance on an Icing Encounters Survey (IES) based data gathering method supporting continuing airworthiness organizations in improving fleet safety and capabilities during cold weather operations.
This paper describes the methodology, involving testing and simulation activities, to assess malfunction conditions of complex systems installed on fly-by-wire vehicles, including the evaluation of their effects. This paper provides also a description about how the system malfunction tests are designed, driven by input requirements and systems capability and behavior. With respect to prior publications, this paper includes some practical test examples, based on systems monitoring, logics and alerting functions. The case study described here comes from a portion of multiple laboratory certification tests done for AW609 Tiltrotor, focused on Avionics System malfunctions. These tests and simulations are a valuable Means of Compliance with respect to applicable airworthiness rules, and a suitable means to verify the design safety requirements. Three relevant examples are presented, grouped by input requirement and safety conditions. The effect of such malfunctions is evaluated, with
The development of turbulence criteria to provide early guidance for the design of vertiports is presented in this paper. For any aircraft, winds, in particular crosswinds and gusty winds, are top of mind for all pilots engaging in take-off and landing maneuvers. It is anticipated that the same will be true for VTOL and eVTOLs landing on vertiports, in particular as new vertiports are built closer and closer to urban centres. First, a review of the current design criteria for vertiports around the world related to wind is presented, highlighting the commonality between the guidance and the gaps in their content. Second, the controllability criteria that VTOL and eVTOLs will likely need to meet in the pursuit of an airworthiness certification are reviewed and their pertinence with regards to vertiport design are discussed. Third, the characters of the wind and their impact on eVTOL flights at or near take-off and landing infrastructure is explored. Finally, a set of turbulence criteria
To this point in aviation history, a typical aircraft type certification program has focused on the constituent systems that make up the aircraft, decomposing them further and further down until reaching their elemental parts and how they interact. This approach has traditionally treated the actual communication technology as only an interface, with technology and implementation based on a decision between multiple stakeholders via an ICD and high-level requirements. This has been necessary to ensure the accurate and on-time delivery of safety-critical data between nodes. When using legacy point-to-point or bus-based data communication technologies like ARINC 429 or MIL-STD-1553, this approach has worked well enough as these technologies are relatively straightforward and proven technologies. However, as onboard bandwidth needs for safety-critical data increase, these legacy technologies are increasingly no longer capable of meeting the needs of system integrators. Ubiquitous, high
As imbedded as it is in technology, the history of flight is also chock full of people stories. The history of the helicopter, one of the most versatile flying machines ever designed, abounds in such stories. This text looks at the development of Intercity Airlines Company's SG Mark VI by a unique team based for a time in Montreal, Quebec. Bernard W. Sznycer and Selma G. Gottlieb conceived one of the most advanced and innovative helicopter of its day. Designed to minimize vibrations and facilitate production, the SG Mark VI first flew in July 1947. Canada's Department of Transport awarded a Certificate of Airworthiness to a second prototype, in April 1951. The SG Mark VI was the first helicopter designed within the British Commonwealth of Nations to be so honored. Sadly, by then, American helicopters all but dominated the civilian and military markets. The SG Mark VI was abandoned during the winter of 1953-54 and both Sznycer and Gottlieb returned to the United States.
Under the Rotorcraft Structural Integrity Program (RSIP) Pilot Demonstration effort, the requirements defined in MILSTD-3063 were applied to a Future Vertical Lift (FVL) representative, model performance specification objective aircraft to demonstrate a standardized RSIP process. This paper covers application of the MIL-STD-3063 approach on SB>1 DEFIANTTM airframe structural components and presents the evolution of the resulting RSIP Master Plan. Elements of the resulting Master Plan are discussed in detail. The Master Plan is the basis for collaborative establishment of structural integrity with an efficient and effective airworthiness substantiation footprint. The discussion includes case studies of the application of logic flow to requirements in MIL-STD-3063 for the determination of specific, relevant action items to airframe structural demonstration components. Execution of this pilot effort led to lessons learned and highlighted feedback to inform the ongoing development of the
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
Additive manufacturing (AM) is currently being used to produce many certified aerospace components. However, significant advantages of AM are not exploited due to unresolved issues associated with process control, feedstock materials, surface finish, inspection, and cost. Components subject to fatigue must undergo surface finish improvements to enable inspection. This adds cost and limits the use of topology optimization. Continued development of process models is also required to enable optimization and understand the potential for defects in thin-walled and slender sections. Costs are high for powder-fed processes due to material costs, machine costs, and low deposition rates. Costs for wire-fed processes are high due to the extensive postprocess machining required. In addition, these processes are limited to low-complexity features. Incremental improvements in all of these areas are being made, but a step change could potentially be achieved by hybrid processes, which use wire
Inspecting an aircraft after a known or suspected lightning strike can be a tedious and subjective task. While aircraft technical manuals do provide conditional inspections following a lightning strike, these inspections tend to be broad in their approach and based solely on the presence of visual damage. This paper discusses the simple technique of tracing the lightning path through the aircraft by the use of an analog magnetometer to identify ferromagnetic parts that have been magnetized by the substantial electrical current of a lightning strike. While this technique is not novel, it is not often published as an inspection technique. Knowing the approximate path of the lightning can assist aircrews and maintainers in the identification of suspect parts that may require further inspection, repair and/or replacement thereby increasing safety and ensuring continued airworthiness of the aircraft.
As the U.S. Army endeavors to maintain overmatch capability in the global arena, Future Vertical Lift has become a high priority. In a climate that demands a more efficient and affordable acquisition process, it is imperative that structural integrity requirements are maintained as a priority to ensure initial quality, supportability, and maintainability considerations. Therefore, it is paramount that a standard practice be utilized so that structural integrity requirements are clearly understood by the Product Office, the Airworthiness Authority, and the Original Equipment Manufacturer(s). This paper highlights how the MIL-STD-3063 U.S. Army Standard Practice for Rotorcraft Structural Integrity Programs can meet these demands by laying out interrelated functional tasks in a concise manner to allow for decision makers to make sound choices with regards to structural integrity for any new developmental aircraft. The paper also details how the standard practice is being utilized to
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
ABSTRACT The current avionics integration approach is becoming unaffordable partly due to the schedule and cost associated with integrating an avionics system into each configuration of each platform using its native interface. The United States (U.S.) Army's Aviation and Missile Research, Development, and Engineering Center (AMRDEC) Director for Aviation Development tasked the Modular Integrated Survivability (MIS) team to work with the U.S. Army Aviation Engineering Directorate (AED), the Army's airworthiness authority, to explore innovative integration approaches to streamline the integration process while still satisfying airworthiness certification requirements. AED has been engaged since the inception of the MIS Science and Technology (S&T) program. The MIS team, along with AED, has focused on developing the concept of using capability interfaces to communicate with similar avionics systems. The capability interfaces are built by abstracting the native interfaces allowing for a
Items per page:
50
1 – 44 of 44