Rotorcraft Transmission System HUM Requirements Derived from Design Safety Analysis

1996 ◽  
Vol 210 (3) ◽  
pp. 271-279 ◽  
Author(s):  
D G Astridge
Keyword(s):  
Failure Modes ◽  
Safety Analysis ◽  
Transmission System ◽  
Functional Requirements ◽  
Critical System ◽  
Safety Critical System ◽  
Direct Design ◽  
Potential Failure ◽  
Additional Support ◽  
Indirect Action

Design safety analysis provides a sound basis for determining the functional requirements of a rotorcraft health and usage monitoring (HUM) system for flight safety purposes, since it considers the vulnerability to catastrophic failure of every component in each safety-critical system. The process thereby identifies the components that may be dependent upon effective monitoring systems in order to achieve the system safety objectives. From the analysis of a new transmission system design, examples are given of component potential failure modes that either (a) are expected to be preventable by direct design action, or (b) will require the additional support of indirect action such as HUM provisions. Many of these examples are expected to be applicable to new rotorcraft transmission designs in general. A brief review of analysis procedures appropriate to rotorcraft transmission systems is included.

The Dynamical Systems Safety Analysis by SQMD Method

2014 ◽  
Vol 693 ◽  
pp. 92-97
Author(s):  
Pavol Tanuska ◽  
Milan Strbo ◽  
Augustin Gese ◽  
Barbora Zahradnikova
Keyword(s):  
Dynamical System ◽  
Control System ◽  
Dynamical Systems ◽  
Critical Points ◽  
Safety Analysis ◽  
Critical System ◽  
Safety Critical ◽  
Qualitative And Quantitative ◽  
Safety Critical System

The objective of the article is to demonstrate the principle of the SQMD method concept for performing safety analysis on the example of a dynamical system. The safety analysis is performed in the process of designing a control system for safety-critical system processes. The safety analysis is aimed at using the models to monitor different critical points of the system. For the purpose of modelling, we suggest using the SQMD method combining qualitative and quantitative procedures of modelling and taking both methods advantages.

scholarly journals A comparison of hazard analysis methods capability for safety requirements generation

2021 ◽  
pp. 1748006X2110034
Author(s):  
Nanda Anugrah Zikrullah ◽  
Hyungju Kim ◽  
Meine JP van der Meulen ◽  
Gunleiv Skofteland ◽  
Mary Ann Lundteigen
Keyword(s):  
Process Analysis ◽  
Hazard Analysis ◽  
Functional Requirements ◽  
Critical System ◽  
Safety Requirements ◽  
Safety Critical System ◽  
Analysis Methods ◽  
Resilience Management ◽  
Requirements Generation ◽  
Software Intensive

A safety-critical system comprising several interacting and software-intensive systems must be carefully analyzed to detect whether new functional requirements are needed to ensure safety. This involves an analysis of the systemic properties of the system, which addresses the effect of the interaction between systems and system parts. The paper compares two hazard analysis methods, which are often considered well-suited for such software-intensive systems: the Functional Hazard Analysis (FHA) and Systems-Theoretic Process Analysis (STPA). The focus is on the selection and improvement of the best methods, based on the lesson learned from the comparison of FHA and STPA. The analyses cover the hazard analysis processes, systemic properties, and the criteria of requirements. The paper concludes that STPA is the better choice over FHA. Insights are obtained to align both STPA and FHA methods with the broader topic on risk management, that is, hazard analysis method improvement, cautionary thinking, uncertainty management, and resilience management.

scholarly journals Safety Analysis of a Certifiable Air Data System Based on Synthetic Sensors for Flow Angle Estimation

2021 ◽  
Vol 11 (7) ◽  
pp. 3127
Author(s):  
Angelo Lerro ◽  
Manuela Battipede
Keyword(s):  
Safety Analysis ◽  
Data System ◽  
System Safety ◽  
Critical System ◽  
Flow Angle ◽  
Mean Time Between Failures ◽  
Safety Critical ◽  
Safety Critical System ◽  
Time Between Failures ◽  
Mean Time

This work deals with the safety analysis of an air data system (ADS) partially based on synthetic sensors. The ADS is designed for the small aircraft transportation (SAT) community and is suitable for future unmanned aerial vehicles and urban air mobility applications. The ADS’s main innovation is based on estimation of the flow angles (angle-of-attack and angle-of-sideslip) using synthetic sensors instead of classical vanes (or sensors), whereas pressure and temperature are directly measured with Pitot and temperature probes. As the air data system is a safety-critical system, safety analyses are performed and the results are compared with the safety objectives required by the aircraft integrator. The present paper introduces the common aeronautical procedures for system safety assessment applied to a safety critical system partially based on synthetic sensors. The mean time between failures of ADS’s sub-parts are estimated on a statistical basis in order to evaluate the failure rate of the ADS’s functions. The proposed safety analysis is also useful in identifying the most critical air data system parts and sub-parts. Possible technological gaps to be filled to achieve the airworthiness safety objectives with nonredundant architectures are also identified.

Braking Safety Design and Analysis for Railway Vehicles

2020 ◽  
Author(s):  
Ziwen Fang ◽  
Yanping Zhang ◽  
Caihui Zheng ◽  
Xintian Wang ◽  
Ming Cheng ◽  
...  
Keyword(s):  
System Integration ◽  
Weight Control ◽  
Failure Modes ◽  
Safety Analysis ◽  
Design System ◽  
Preventative Maintenance ◽  
Critical System ◽  
Railway Vehicles ◽  
Safety Design ◽  
Criticality Analysis

Abstract Brake is a safety critical system for railway vehicles and brake failures have caused many catastrophic accidents in the history. Detailed accident investigation reports are available and National Transportation Safety Board (NTSB) also makes safety recommendations to Federal Railroad Administration and the industry. However, there is limited research on how to improve the brake safety from the perspective of design, system integration and safety analysis. In this paper, a framework for braking safety design and analysis is introduced, which includes four parts: failure alarming system, safety design, safety analysis and preventative maintenance. For failure alarming, according to the severity level, the failures will be notified to the operator, to Operation Control Center (OCC) or saved for the maintainer. For safety design, redundant design for fail-safe feature, automatic braking, brake release, weight control, ergonomics design for easy operation and maintenance are discussed and several application examples are illustrated. In the safety analysis section, Preliminary Hazard Analysis (PHA) as a semi-quantitative analysis, Failure Modes, Effects, and Criticality Analysis (FMECA) as a bottom-up method and Fault Tree Analysis as a top-down method are used. The hazards details, system assurance actions and closure references are recorded in the Hazard Tracking Log (HTL) to ensure all the safety related items are well tracked and documented. Preventative Maintenance (PM) which is regularly performed on the brake components to lessen the likelihood of failing is also discussed in combination with the reliability prediction and safety analysis for a balance of safety and economy. The safety design framework and principles introduced in this paper can also be applied into other railway systems, such as Propulsion, Signaling, Doors, etc. and may provide insights to similar industries such as automotive, energy and so on.

scholarly journals Surface Contamination by Antineoplastics in Hospitals: An Observational Study for Mapping of Potential Contamination Associated with Handling Excreta of Babies through Diaper Management

2020 ◽  
Vol 4 (3-4) ◽  
pp. 119-125
Author(s):  
Marie Palamini ◽  
Geneviève Mercier ◽  
Jean-François Bussières
Keyword(s):  
Bone Marrow ◽  
Exploratory Study ◽  
Research Team ◽  
Failure Modes ◽  
Hospital Setting ◽  
Marrow Transplant ◽  
Mother And Child ◽  
Potential Failure ◽  
Key Steps ◽  
Hazardous Drugs

AbstractBackgroundIn the hospital setting, trace contamination with hazardous medications comes primarily from the manipulation of containers used in preparing and administering drugs. However, some traces of medications also come from the excreta of patients.MethodsThis descriptive exploratory study involved direct observation and discussion. The aim was to map potential contamination associated with handling babies’ excreta through diaper management. The study was conducted at CHU Sainte Justine (Montréal, Québec, Canada), a 500-bed mother and child facility with 38 beds for hematology-oncology and bone marrow transplant. A list of key steps related to the management of diapers by a parent or caregiver on a pediatric unit was established by the investigators. A data collection grid was then developed and reviewed by a member of the research team.ResultsA total of six diaper changes, by six distinct individuals, were observed in August and September 2019. Transport of a soiled diaper for weighing outside the baby’s room by an additional caregiver was also observed and recorded. In total, 25 individual steps in diaper management and 28 potential failure modes were identified through mapping.ConclusionsChanging a baby’s diaper involves many individual steps, which are subject to numerous failure modes that can contribute to contamination with traces of hazardous drugs. A good understanding of these process steps and failure modes is desirable to better train caregivers and parents to reduce trace contamination with hazardous drugs.

A Systematized FMEA Practice for Magnet Relays

2010 ◽  
Vol 146-147 ◽  
pp. 757-769
Author(s):  
Ching Ming Cheng ◽  
Wen Fang Wu ◽  
Yao Hsu
Keyword(s):  
New Product Development ◽  
Failure Modes ◽  
New Product ◽  
Risk Priority Number ◽  
Detection Model ◽  
Regulation Function ◽  
Potential Failure ◽  
Weighting Rule ◽  
Rating Criterion

The Design Failure Modes and Effects Analysis (DFMEA) are generally applied to risk management of New Product Development (NPD) through standardization of potential failure modes and effect-ranking of rating criterion with failure modes. Typical 1 to 10 of effect-ranking are widely weighed the priority of classification, that framing effects and status quo senses might cause decision trap happening thus. The FMEA follows considerable indexes which are including Severity, Occurrence and Detection, and need be associated with difference between every two failures individually. However, we suspect that a more systematic construction of the analysis by which failure modes belong is necessary in order to make intellectual progress in this area. Two ways of such differentiation and construction are improvable effect-ranking and systematized indexes; here we resolve for attributes of failures with classification, maturity and experiance of indexes according to an existing rule. In Severity model, the larger differentiation is achieved by separating indexes to the classification of the Law & Regulation, Function and Cosmetic. Occurrence model has its characteristic a reliable ranking indexwhich assists decisionmakers to manage their venture. This is the model most closely associate with product maturity by grouping indexes to the new, extend and series product. Detection model offers a special perspective on cost; here the connections concerned with phase occasion of the review, verification and validation. Such differentiations will be proposed and mapped with the Life Cycle Profile (LCP) to systematize FMEA. Meanwhile, a more reasonable Risk Priority Number (RPN) with the new weighting rule will be worked out for effect-ranking and management system will be integrated systematiclly

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