1、 1 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 From Aircraft Health Monitoring to Aircraft Health Management White Paper on AHM 2 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 Contents 1.Foreword.3 2.Aircraft Maintenance Milestones.5 2.1.Aircraft M

2、aintenance as Means to an End.5 2.2.Maintenance Life of the Aircraft.6 2.3.Evolution of Aircraft Maintenance Concept.7 3.The AHM Paradigm.10 3.1.Defining Vocabulary.11 3.2.Searching Optimization of Aircraft Technical Availability.12 3.3.Securing the Benefits.13 4.Industry Action Steps.15 4.1.Recogni

3、zing Foundations.15 4.2.Developing Capabilities.17 4.3.Creating Standards.18 5.Regulatory Balancing Act.20 5.1.Addressing Necessity.20 5.2.Solving the AHM Puzzle.20 6.AHM Roadmap.24 6.1.Starting Points.24 6.2.Validation Gates and Criteria.24 6.3.Pursuing Implementation.25 7.Conclusions.27 Appendix 1

4、 Abbreviations.28 Appendix 2-Suggested Readings.30 Appendix 3-Acknowledgements.31 Figure 1:Reliability Bookmarks.5 Figure 2:Maintenance Taxonomy Excerpt.6 Figure 3:Driving Factors in Scheduling Maintenance.8 Figure 4:Layered Setup of AHM Readiness.10 Figure 5:Uncertainty Matrix of Reality and Percep

5、tion.15 Figure 6:Steps Marking the Life-Cycle.16 Figure 7:Integration and Capability Milestones.17 Figure 8:Levels of Analysis in MSG-3 Logic.19 Figure 9:Pieces of the Puzzle.21 Figure 10:Steps to Take for AHM Implementation.25 3 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022

6、 1.Foreword Managing the technical availability of the aircraft is key in accomplishing your mission,whichever is your stakeholder status vis-vis the aircraft asset:Airline Operator,Aircraft OEM,Aircraft MRO or Aircraft Owner/Lessor.In assessing the potential impact of(un)availability,operators asse

7、rted that aircraft dispatch delays can cost$10K(or more)per hour with flight cancellations imposing a financial penalty of$100K(and above)per instance.Hovering consistently well above a 99%benchmark of aircraft technical availability implies a careful steering of the aircraft maintenance with a shar

8、p focus on preserving the capabilities and performance of the asset close to its“as new condition”.Hence,the needed enabler for a 24/7 visibility on,awareness of,and action to maintaining the required level of aircraft health.Accomplishing the above is the main objective and direct result of a robus

9、t Aircraft Health Management(AHM).The AHM means using aircraft and fleet generated data to promptly identify the individual aircrafts needs for maintenance work and trigger an effective and efficient maintenance action.This is an end-to-end comprehensive process,which encompasses aircraft systems,da

10、ta transfer and electronic processing,data analysis,and subsequent informed decision on improved,re-defined,or alternative methods to maintenance tasks.Such a process includes both“on-board”and“off-board”sequences and its results are highly relevant to planning and executing the aircraft scheduled m

11、aintenance program or the ad-hoc required maintenance action.It is a dynamic action-oriented approach and a consequential evolution of the already acknowledged albeit more“passive witnessing”field of Aircraft Health Monitoring.This White Paper is a quick review of what AHM implies and could possibly

12、 empower its adopters to perform,in the not-too-distant future,towards ensuring the economically optimized technical availability of the aircraft.While there is no substitute(at least not yet)to the aircraft maintenance action requiring the maintenance staff“hands-on”presence for physical accomplish

13、ment of an aircraft part replacement or repair,implementing the AHM approach would position the practitioner to make the optimum decision regarding such maintenance action.Predictive maintenance employing health monitoring mechanisms is estimated to enable airlines around$3B per year in maintenance

14、cost savings.The objective of this White Paper is to:a)familiarise the industry with the technological revolution that the use of data collected from the aircraft can improve the levels of safety and efficiency,b)provide a roadmap to capitalize on this data usage,and c)address challenges and opportu

15、nities that this will bring to the industry.Empirical data indicate that,for the average operator,over 70%of its scheduled maintenance program“fault finding tasks”resulted in“no findings”.This maintenance execution fact coupled with utilizing the alternative of AHM-based tasks to enable a condition-

16、based maintenance versus on-wing manual preventive maintenance tasks will result in:a)significant cost reductions for the operator,and b)increased aircraft on-time performance and improved dispatch reliability as real time data is either pro-actively or reactively used by operators to address aircra

17、ft systems or structural issues before faults could develop into functional failures affecting the aircraft technical availability.Adopting and operationalizing a refined AHM path will naturally lead civil aviation actors to also explore new ways of guarding the safety level priority in the context

18、of ever-growing complexity of aircraft and their operation.Critically important for all entities in the aviation ecosystem is that Airworthiness regulatory authorities approving and overseeing the AHM implementation do engage the industry and consider their feedback in designing the safest and most

19、efficient aviation framework.4 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 Recently manifested radical progress factors and technology disruptors like Big Data and Cloud Services,Industrial Internet of Things,Artificial Intelligence and Machine Learning,Industry 4.0 and Di

20、gital Twins are all major potential contributors to shape and empower the AHM.This White Paper is an invitation for all industry stakeholders to consider the AHM ensuing benefits in building the future success of the entities and communities they belong to.Sharing AHM related ideas,initiatives,exper

21、iences,and results would benefit the entire aviation ecosystem and this White Paper is intended to enhance the interest in that direction.Looking forward to receiving any feedback at Techopsiata.org.5 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 2.Aircraft Maintenance Miles

22、tones While not always visible to aircraft operation direct beneficiaries,aircraft maintenance is a constant presence enabling the aircraft asset to deliver along its entire life the expected financial and business values without any hindrance due to aircraft technical status.The recognition of airc

23、raft technical availability key role is unanimous,although one should always check the definition of this KPI for common acceptance basis and interpretation awareness(see reference 1 in Appendix 2 for a detailed discussion).2.1.Aircraft Maintenance as Means to an End Airline Operators are aware that

24、 aircraft maintenance,notwithstanding its“must have”regulatory status,is just the means to support the desired end outcome of aircraft fleet operational readiness.The perspective of a“self-healing”aircraft is still a distant one even if some of the edge research in self-diagnostics and self-repair o

25、f complex structures is bringing such aircraft of the future out of the Science Fiction realm and closer to aviation attainable goals.In this context,the first step to ensure the desired technical availability of the aircraft is to set-up an appropriate maintenance activity,which is focused on and s

26、upports the airworthiness,technical capability and performance of each aircraft,as demanded by the airlines operation schedule.While clearly distinct from it,the aircraft technical availability relies first and foremost on the aircraft reliability.Figure 1:Reliability Bookmarks 6 From Aircraft Healt

27、h Monitoring to Aircraft Health Management Feb 2022 The reliability which an operator could achieve for the aircraft(i.e.,“individual tail reliability”)is lower than,or at best equal to,the aircraft reliability performance intrinsically resulted from the design of the aircraft type and production of

28、 the aircraft unit.The aircraft“built-in”reliability threshold resulted from design and production is the maximum achievable level of reliability in operation.Aircraft maintenance,however diligent and effective,would not result in exceeding that threshold and operators should acknowledge it as a lim

29、itation which is out of their control and is dependent on the aircraft design and production.Only with a well-conceived and implemented Aircraft Maintenance Program(AMP)could the operator eventually achieve that end level of reliability.Airlines are requested by regulation to have a Reliability Prog

30、ram for their fleet by considering several sources of information(e.g.,Pilot Reports PIREPS,Maintenance Reports MREPS)and operationalizing a Failure Reporting,Analysis and Corrective Action System FRACAS.Additionally,operational relief mechanisms involving dispatch under Minimum Equipment List(MEL)a

31、nd Configuration Deviation List(CDL)are,in some circumstances,facilitating a limited technical availability of the aircraft,albeit they are not intended to and could not address a lack of reliability issue.AHM potentially becomes a key enabler of optimized AMP implementation;its direct impact on sec

32、uring the aircraft technical availability makes it an important tool for airlines in achieving the desired level of Dispatch Reliability(DR).2.2.Maintenance Life of the Aircraft The aircraft“maintenance life”is effectively starting once the production test flight of the aircraft is performed althoug

33、h the clock and focus for technical,commercial,and regulatory compliance activities with aircraft maintenance relevance is initiated“de jure”at the time of aircraft delivery to its first operator.Exploring the taxonomy of aircraft maintenance types is a multi-layered exercise with numerous categorie

34、s of maintenance activity being distinguished based on the criteria considered to define them.A non-exhaustive list of examples would include grouping by:location and complexity of activity execution during the aircraft operational life(i.e.,line or base maintenance).volume of activity committed and

35、 its optimization for the timing and duration of execution(i.e.,equalized or block maintenance).nature of activity in relation to the technical content of the executed maintenance tasks(i.e.,preventive or corrective maintenance).prior level of planning granularity/comprehensiveness governing the act

36、ivity(i.e.,scheduled or non-scheduled maintenance).Figure 2:Maintenance Taxonomy Excerpt 7 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 Each criterion is capturing the dominant feature of that category of maintenance and the very same maintenance task could be simultaneousl

37、y identified as belonging,for example,to preventive,block and base maintenance.The individual airline will always seek to build and adopt the AMP best suited to its own operational profile and fleet;the resulting aircraft maintenance activity planning and execution will account for the specific cons

38、traints and conditionalities.This could result in a very tailored packaging of maintenance tasks which accommodates to the best possible level the particular operation.Reviewing the frequency of aircraft parts failure,a series of patterns were identified in the attempt of linking the occurrence of s

39、uch failures to the operating time(or the relevant use control parameter)of the part.The conclusion was that most functional failures(approx.89%of them)in a complex machinery like the aircraft occur following a deterioration model which is not“age related”but rather“random”(see reference 13 in Appen

40、dix 2 for more details).The emergence of software parts which the configuration of modern aircraft comprises(e.g.,currently,the B787 counts around 1400 instances of such parts in its listed configuration)seems to bring no major change to the above conclusion which is based on legacy configuration ai

41、rcraft(i.e.,in-service by 1980).While the conclusion drawn constitutes an important element which the AHM must consider,the corelations unveiled by a continuous and detailed monitoring of parameters could be an AHM opportunity to pursue when attempting to explore the previously observed randomness.2

42、.3.Evolution of Aircraft Maintenance Concept In its history beginning phase,aircraft maintenance was mainly of corrective type fix the equipment once it has broken and failed to fulfil its intended function-with the addition of some servicing maintenance actions(e.g.,cleaning and lubrication)and lim

43、ited restoration of condition to“as if new”when the need to recover evident loss of performance was identified.This approach evolved later to include scheduled restoration,overhaul or replacement of equipment and parts.The intent of such maintenance actions was preventive in nature with the scope of

44、 increasing reliability of subject equipment and parts and it was based on the belief that the more maintenance the aircraft undergoes the better its reliability will be.This view resulted from across-the-board application of the“bathtub model”of failure and its assumed wear-out zone while,at the sa

45、me time,ignoring the failure rate injected into otherwise stable operating systems by unnecessary maintenance actions.The Maintenance Steering Group(MSG)became the aerospace industry driving force to introduce the systemic engineering approach to aircraft scheduled maintenance development.This forma

46、lized a decision logic flow which was permanently refined and reflected in the successive standards document MSG-1/-2/-3 with a notable mechanism for periodic revisions of MSG-3.8 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 Figure 3:Driving Factors in Scheduling Maintenanc

47、e The major step in this evolution was to recognize that performance of maintenance should be targeting function preservation at the aircraft level rather than focusing on the component failure per se.This evolution resulted in:the system level and top-down approach for function identification,inste

48、ad of a component level and bottom-up approach.the consequence-driven approach,starting with the failure identification as“hidden”or“evident”to the flight crew and“safety”or“non-safety”categorization to ensure specific addressing controls of the risk of failure.the function preservation instead of f

49、ailure prevention,to ensure the system function and the availability of protective devices.the task-oriented approach instead of a maintenance process-oriented approach to preparation of a maintenance programme.This evolution history started with embracing three types of maintenance processes:Hard T

50、ime(HT)defined as the preventive process in which known deterioration of a system or component is limited to an acceptable level by the maintenance actions which are carried out at periods related to time in service or other corresponding control parameter(e.g.,calendar time,number of cycles,number

51、of landings).The prescribed actions restore the system or component utility margin to the applicable control parameter limitation.Examples:overhaul the landing gear;discard the cartridge of the engine fire extinguishing;discard cabin crew protective breathing equipment.On Condition(OC)defined as the

52、 preventive process that requires a system or component be inspected periodically or checked against some appropriate physical standard to determine if it can continue in service between the periodic maintenance actions.The standard ensures that the unit is removed from service or undergoes the nece

53、ssary maintenance action before failure in service.Examples:Lubrication tasks,Operational Checks,General Visual Inspections.Condition Monitoring(CM)defined as the process for systems or components that have neither HT nor OC maintenance as their primary maintenance process.It is accomplished by appr

54、opriate means available to an operator for finding and solving problem areas.This is not a preventive process,and the system or component are permitted to remain in service without preventive maintenance until a functional failure occurs.The CM is often abusively equated with“run-to-failure”or“fit a

55、nd forget”philosophy,ignoring that many components maintained under such a process are removed before their failure in service if related repair costs would justify removal.Examples:maintenance of Passenger Convenience Items or Non-Essential Equipment and Furnishings.9 From Aircraft Health Monitorin

56、g to Aircraft Health Management Feb 2022 It should be noted that in-shop maintenance practice for off-wing components may be following what is sometimes referred to as“soft-time intervals”philosophy which,for example in the case of an engine,retains in essence the“on-condition”maintenance practice a

57、nd minimizes the impact of additional module disassembly.While in general these maintenance processes are not driving the aircraft maintenance concept anymore(exceptions may be encountered for legacy fleets),it is worth emphasizing that CM is not linked to achieving OC maintenance.Another misleading

58、 association is to assume any commonality between CM and CBM.Condition Based Maintenance(CBM)is a type of maintenance activity that determines the condition and remaining useful life of the component/equipment and consists in maintenance performed based on evidence of need in order to maximize the u

59、tilization of economic life of that component/equipment.The CBM,through its application and integration of appropriate processes,technologies,knowledge-based and prognosis capabilities,represents a major evolution of the OC type of maintenance and,by enabling the optimal failure management strategie

60、s depending on system reliability characteristics and the intended operating context,it essentially fits under AHM.Avoiding confusions associated with various interpretations is benefiting also from the evolution of MSG standards:the MSG-3 departed from the HT,OC and CM concepts which were central t

61、o the MSG-2.A significant evolution in the decision logic established for developing the aircraft scheduled maintenance would be to accommodate the AHM implementation.Such development would be possible in the next MSG-3 revision(envisaged for 2022)by including the optional level of analysis adopted

62、through IP-180(see section 4 for details).Takeaway Aircraft maintenance shall be strictly supporting the technical availability of the aircraft asset for safe flight operation and integrate the airline operator specific elements in the process of doing so in an effective and efficient way.Implementa

63、tion of AHM is a logic step to consider in the evolution of aircraft maintenance concepts,especially as they apply to the new level of technology defining the recently certificated aircraft types.10 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 3.The AHM Paradigm Engaging in

64、to AHM implementation is conditional to having both the DAH/OEM and the Operator successfully reach the necessary readiness level and assume the AHM specificities consistent with their roles as recognized and endorsed by the Regulator.The multi-layered essence of this required three-legged construct

65、 is summarized in the figure below.Although robust addressing of safety remains the main driver,commercial considerations(e.g.,costs and contractual agreements)do have their role in some of the intra and inter layer connections implied in the above figure.While building the AHM readiness requires ea

66、ch stakeholder to explore and master new elements,a previous exploit in aviation consisting of the ETOPS/EDTO implementation-is a valuable procedural model to follow.Several tenets worth be reminded for their relevance to the AHM paradigm:Figure 4:Layered Setup of AHM Readiness 11 From Aircraft Heal

67、th Monitoring to Aircraft Health Management Feb 2022 With a fundamental role in aircraft airworthiness and,thus,essential to aircraft flight safety,the aircraft maintenance actions must be executed whenever necessary and shall always encompass the sufficient level of detail.Thus,the maintenance acti

68、on must meet both the necessity criterion and the sufficiency criterion.The AHM purpose is to produce the aircraft accurate health indicator which would constitute the evidence of maintenance need and guide the granularity of work to be performed based on the condition and actual use controlling par

69、ameter of the equipment instead of a specified calendar time or generic use limits.The key enabler in pursuing any maintenance credits for AHM is to identify and address the product certification and operational authorization precursors in a way commensurate to the AHM use case.Implementation of AHM

70、 requires a capability level not only for the initial qualification phase(e.g.,aircraft type certification and production certification;airline infrastructure,processes,procedures,and personnel)but also for the continued preservation of such qualification(e.g.,in-service experience/data driven revis

71、ions/updates).Portability between maintenance systems with and without AHM over the operational life of the aircraft asset should be ensured and AHM should be viewed and developed as“the option”and not“the obligation”of airline operators.Exploring the concept of certification of“AHM dependent produc

72、t design”is a possible future direction envisaged by OEMs.3.1.Defining Vocabulary The aircraft maintenance concepts,even when new and somehow disruptive approaches were adopted,has always provided to its practitioners a cohesive evolution from one construct to the next and AHM is no exception.There

73、is however a certain level of on-going dynamics regarding the definition,acceptance and use of some of the terminology or categorization involved in the emergence of AHM and related activities.This could generate overlapping,duplication,or misalignments(even apparent contradictions)which the industr

74、y and regulatory stakeholders are called upon limiting;flexibility is desired and would benefit AHM implementations,but vagueness and/or lacking consistency would hamper any progress in AHM use.Often enough,a close scrutiny of the wording used and the associated definitions may indicate more of a ma

75、rketing or trademark motivation rather than a substantial conceptual differentiation.While a definitive coining of the AHM vocabulary is out of scope and would be an unattainable pursuit for this paper,there are a few elements to highlight in support of a common understanding basis:Aircraft Health M

76、anagement(AHM)is the unified capability of using health monitoring of aircraft structure and systems(including propulsion system)to control the scheduling of aircraft needed maintenance actions;could be resumed to the process stages of Sense,Acquire,Transfer,Analyse and Act(SATAA).Aircraft Health Mo

77、nitoring is the technique of monitoring the output of a single and/or multiple condition indicators during operating conditions used to diagnose faulty states and predict future degradation of the equipment;could be resumed to the process stages of Sense,Acquire,Transfer and Analyse(SATA).12 From Ai

78、rcraft Health Monitoring to Aircraft Health Management Feb 2022 Fault vs Failure should be understood as the anomaly identified in a component or system without impact on the required functional output of the item or system vs the inability of a component or system to perform its functional role wit

79、hin previously specified limits.Potential to Failure(P to F)is an interval(expressed in functional use control parameter units),counted from the presence of a defined identifiable condition at its earliest point of detection/diagnosis,at the end of which the degradation process triggered by the cond

80、ition leads to a functional loss of the component or system;it is a value which once predicted remains constant for the entire degradation period.Remaining Useful Life(RUL)is the remaining segment of the P to F at the time of discussion;it is a value which decreases from the P to F value(if the time

81、 of discussion coincides with the origin of P to F)to zero(if the time of discussion coincides with the functional loss).Failure Mode vs Failure Cause vs Failure Effect should be understood as the way in which a component/system can fail vs why the component/system failed in the observed mode vs the

82、 result/consequence which the failure of the component/system has.Condition Indicator vs Health Indicator should be understood as the result produced by an algorithm that combines one or more features of a component or system and which is representative of the state of the component or system vs the

83、 result of one or more condition indicator values cumulated to signal a need for a maintenance action.Predictive Maintenance is the maintenance process with the objective to answer“what and when”will happen with the asset which is maintained.It consists in the prediction of future events based on hi

84、storical and real-time collected data;it employs sophisticated data analytics and automated maintenance workflow elements with possible AI tools.Prescriptive Maintenance is the maintenance process elevating the prediction capabilities(see the predictive maintenance process discussed above)by adding

85、adaptation and optimization capabilities which enable it to not only predict“what and when”for the event which will happen but also recommend“how”to resolve the event;it employs sophisticated data analytics and automated maintenance workflow elements including AI tools.3.2.Searching Optimization of

86、Aircraft Technical Availability Statistics indicate that,depending on the aircraft type and use category/destination/market,somewhere between two thirds and four fifths of maintenance generated unavailability originate from planned maintenance with the rest coming from unplanned maintenance activity

87、.In general,due to operational considerations,from the airline perspective the unavailability“unit cost”ends by being much higher for non-operating time due to unplanned maintenance rather than planned maintenance.The planned maintenance activity would benefit from AHM implementation through its inh

88、erent optimization since maintenance resources would be focused on evidence of need provided by health indicators of the aircraft asset.In essence,introducing AHM in the equation of the rationale driving the content of scheduled maintenance,the planned maintenance can be optimized and implicitly the

89、 related unavailability contained to its feasible minimum.Additionally,one of the main strengths of an AHM proposed approach and a major source of attracting the active interest of airline operators,is to transform many unpredictable maintenance events into predictable ones and properly plan for the

90、m.The capability of additionally reducing operational interruptions from unplanned maintenance events is particularly appealing to airlines.13 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 AHM should provide visibility and knowledge of the aircraft actual usage with a suffic

91、ient level of detail and supporting data.Usage monitoring information comprising data regarding operational regimes,functional parameters and operational environment would generate a refined actual usage identification spectrum of the aircraft structure,systems and components.The potential consequen

92、ce would reach from improving the accounting of the maintenance control parameter triggering the execution of a maintenance task up to influencing the decision if the life limit of an LLP was attained or not.The above-mentioned potential consequence is recognized as an opportunity already explored b

93、y engine DAHs with the concept of Usage Based Lifing(UBL).This would compensate for the unintended over-conservative effect of design and certification assumptions in the case of a low severity usage.The reversed situation could also happen,whereby AHM outcome safely compensates an under-conservativ

94、e assumption in the case of higher than design-assumed usage severity.3.3.Securing the Benefits Quantifying the value of AHM is a fundamental step for each category of stakeholder before engaging on the AHM avenue and there are different weights attached to individual benefits depending on the stake

95、holder identity(e.g.,airline,OEM,MRO).The assessment should consider the potential safety,operational and economic benefits.Enabling a constantly actualized characterization of the in-service condition of an aircraft system or component with the real(or almost real)time continuous collection of data

96、 which the AHM entails,could become a significant benefit in the aircraft operational safety equation.The potential of having a continuous monitoring versus a discrete interval visibility,would enable moving the maintenance action promptitude and its time horizon on a different coordinate with ensui

97、ng benefits to aircraft safety.The AHM benefit pool comprises the categories of short-term ones e.g.,visibility and understanding of a system/component deterioration enables to optimize the timing and the level of maintenance action to avoid operational disruptions,and long-term ones e.g.,prioritize

98、,relying on AHM,the component restoration or repair for an economic optimum regarding the maintenance cost.When deciding on any particular AHM implementation four questions will be asked from start by the airline considering it:Does AHM solve some of the issues the airline is faced with and would it

99、 bring new opportunities to airlines operation?Is AHM technically feasible in airlines organizational context and resources?Would AHM be a sustainable operation for the airline to engage-in?What is the level of regulatory involvement needed for approval and oversight,and could that be secured by the

100、 stakeholders concerned?Integrating the AHM basis in aircraft maintenance would unlock a broad range of benefits including higher productivity,decrease in maintenance turn times,lower costs,increased quality of the process and would deliver finally a better technical availability and enhanced dispat

101、ch reliability of the aircraft.14 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 It shall be recognised nevertheless that tailoring AHM for implementation on a targeted platform aircraft must consider what is practical to implement versus attempting by default to apply AHM ac

102、ross the board for all equipment/components which are part of the aircraft configuration.AHM suitability relies essentially on the measured condition of aircraft systems,equipment or components and their actual values of usage control parameters.Aircraft design configuration technical elements or ai

103、rline operational procedures inability to deliver such information would rule out AHM applicability.Based on the typical use of classic scheduled maintenance tasks for all aircraft systems(i.e.,including propulsion systems)it is asserted that up to 90%of those tasks result in“no finding”.This statis

104、tic would lead to the rather staggering conclusion that 90%of aircraft ground time for systems scheduled maintenance does not change the condition of the aircraft.Is that a waste of labour and material resources?Additionally,it is asserted that more than 60%of the systems functional failures(i.e.,co

105、nsidering the total across all FECs)had no scheduled maintenance tasks selected through the typical maintenance program development process.The potential to change the above through a robust implementation of AHM is a strong motivator for action.Takeaway The willingness to address the burden of unne

106、cessary labour and material resources resulted from the typical scheduled maintenance development is a strong incentive for AHM implementation.While there are up-front costs involved by AHM implementation,and all categories of stakeholders should assume their share,in general“the potential gain is w

107、orth the pain”.Individual scrutiny for feasibility and sustainability should be applied to each AHM use case.The AHM future requires a high level of automation with data science developed processing algorithms running in an AI/ML setting made possible by AHM ready aircraft products and components.15

108、 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 4.Industry Action Steps Like most developments in civil aviation,the exploration of AHM concept emerged from the aviation industry push to refine what and how to perform for aircraft maintenance once the asset commenced its serv

109、ice life.While airlines are the ultimate enabler and user of the AHM implementation,hence their active role in building a coherent and fit for purpose sustainable construct,developing the AHM path could not be envisaged as the effort of a single category of stakeholders(see considerations presented

110、in section 3)and outside of a wide-reaching harmonization.IATA is at the forefront of advocating and pursuing such harmonization and several of the status relevant elements are summarized in sections 4 and 5.This section is presenting some of the aviation industry debated elements and the successful

111、ly undertaken steps by entities participating in forums like the(IATA)Engineering and Maintenance Group/Technical Operations Working Group(EMG/TOWG),Maintenance Programs Industry Group(MPIG),and SAE International.Significant follow-up steps are needed and expected from the industry to improve and im

112、plement the AHM approach promoted by the forums mentioned above.4.1.Recognizing Foundations The AHM consists fundamentally in looping the aircraft health data through the process stages of Sense,Acquire,Transfer,Analyse and Act(SATAA).The loop starts at the aircraft asset level with the physical sen

113、sing of one or more parameters and eventually ends at the aircraft asset level with the physical execution of a maintenance action.Each one of the stages is essential by itself and the AHM would be as robust as the weakest link of the SATAA chain.For each stage there is a primary role assumed by one

114、 stakeholder,but the success of that stage delivery will always depend on(at least one)secondary role fulfilled by another stakeholder(e.g.,for S the aircraft configuration must physically have the sensing capability thus DAH/OEM is a primary stakeholder but that capability/part must be properly ope

115、rated/maintained-thus Airline is a secondary stakeholder).The degree of accuracy between the actual real condition/state of the asset and the one perceived or predicted is at the core of AHM and the agreement/disagreement of the two is reflected in the Uncertainty Matrix.Figure 5:Uncertainty Matrix

116、of Reality and Perception 16 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 Considering that a Health Indicator is positive when indicating a failure,the resulting errors in diagnosing the system/component emerge as a False Positive(when the healthy system is perceived as fai

117、led)or a False Negative(when the failed system is perceived as healthy)and would affect the predictive capability of AHM.Parsing the uncertainty starts at the Sense stage but extends to the Analyse stage thus depending on the sensor as much as on the predicting algorithm or modelling of the system/c

118、omponent.The AHM with a robust predictive capability performance will generate a“TRUE”outcome subsequent to a successfully executed diagnostics(process which corresponds to“perceived”)or prognostics(process which corresponds to“predicted”).AHM is relying on data reflecting the set of parameters of i

119、nterest originating from the aircraft/systems.The capability of processing the data and run it through algorithms which model the aircraft/systems supports the predictive performance of AHM bridging from“Normal”to“Remaining Useful Life(RUL)”.Data generation and collection rates,latency of data avail

120、ability and securing data quality(through appropriate procedures for data cleansing and wrangling)are all raising several specific issues which must be addressed in each one of the steps depicted above.Some fundamental elements considered in the life cycle suggested process should be:There is a cert

121、ain variability of normality in operation from one asset to the next;establishing the baseline of normal functioning must be calibrated for the asset and it may also drift with usage in service.Any excursion of a parameter from its baseline is a deviation but not all qualify as anomalies;the context

122、 of the deviation must be available for such a qualification to be made;having an anomaly detection system does not equate with having a diagnostics system.The aircraft/systems modelling would identify which anomalies are symptoms representative of an incipient failure and based on this potential to

123、 failure(P to F)the RUL could be predicted.Figure 6:Steps Marking the Life-Cycle 17 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 The predicted RUL depends on the type of terminal event it accounts for(i.e.,RUL to avoid damage;RUL for economic repairability;RUL for loss of f

124、unction)and is always affected by an uncertainty distribution curve of its estimation.The modelling of the aircraft/systems could be derived from engineering applied laws of physics or could be a data-driven model;each of the two has pros and cons and adoption of one or the other is conditional to s

125、pecifics of the business case.4.2.Developing Capabilities The adoption of AHM should not be contemplated as a panacea to aircraft maintenance and it would always depend on the capabilities of the solution proposed.Pondering applicability and effectiveness for maintenance tasks will be the deciding c

126、riteria since measuring loss of performance,deterioration and condition with the aircraft in-service is sometimes technically challenging and it could be cost prohibitive.The table below summarizes the general discussion regarding the evolution of AHM capability sophistication and its expected integ

127、ration level with the aircraft asset.The table is an adapted partial excerpt from a more detailed matrix and classification criteria proposed by SAE International(check reference 12 in Appendix 2).Figure 7:Integration and Capability Milestones 18 From Aircraft Health Monitoring to Aircraft Health Ma

128、nagement Feb 2022 The accuracy of prediction is time-horizon dependent and only predicting with a reasonable variance would be of interest to aircraft maintenance practitioners.When discussing the capability of enacting AHM,a clear understanding and distinction between the diagnostic phase(as repres

129、enting a classification problem)and the prognostics/predictive phase(as representing a regression problem)should be made.Although any reliable prediction is dependent on the accurate/detailed diagnostics which precedes it,the latter is not ensuring the existence of AHM in the true acceptance of the

130、concept.The role of modelling the component/system/aircraft to enable the in-service data-driven informed and credible prognostics is essential to AHM.The DAH/OEM models with first principles basis already passed the certification scrutiny and were used to explore all corners of the aircraft flight

131、envelope but they may not be available to operators.Although the alternative of a post EIS data-driven model exists for the operators,we should note that data-driven/data-derived models are merely a representation of their training data set;addressing a novelty in the operation mode when triggered b

132、y airline business priorities(e.g.,new flight profiles or flight environments)could be challenging such a model.Another important feature of the AHM capability discussion is the level of automation.This permeates each step of AHM:starting from parameter sensing and data collection,following with the

133、 in-flight real-time transmission to ground(rather than post landing download/transfer/access)continuing with the processing and maintenance decision support systems which involve AI and ML techniques.Automation is in fact the condition for viable scalability of AHM;ensuring a reliable,unaltered,and

134、 secure data flow compliant with cybersecurity standards is paramount to the integrity and credibility of the AHM program.Given the big data which the AHM handles and relies on,extended automation is the only way forward and a complete automation is very likely to follow.4.3.Creating Standards The b

135、ody of standardization work with AHM significance comprises on one hand provisions focused directly on the design and integration of its functional elements as well as their subsequent operational use and on the other hand provisions indirectly touching on features met by it.In one category the bar

136、is set by MPIG and SAE while the other category benefits from deliveries of RTCA and EUROCAE.Given its impact on the aircraft maintenance activity practitioners at the aircraft in-service level,which is where AHM should make the difference,the synthesis of what is entailed by opening MSG-3 to AHM is

137、 mentioned below(check reference 5 in Appendix 2 for more details).The traditional MSG-3 logic flow which consists of two levels of analysis of the aircraft systems to select an applicable and effective maintenance task is enhanced with a third level,entirely optional,to be applied for identifying a

138、n alternate with AHM basis in eligible cases resulted from the previous logic flow level.19 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 Figure 8:Levels of Analysis in MSG-3 Logic To enable the execution of analysis at Level 3 the amount of additional work involves extensiv

139、e preparatory material to address AHM linked details,parameters,interfaces,functional description,P to F and software certification elements.The systems/components part of the aircraft certificated configuration added for AHM purposes generate themselves the dedicated MSI analysis.The possible outco

140、mes could lead to a full replacement of the classic task(in the case of the“alternative”selection)or to a partial replacement of the classic task(in the case of“hybrid”selection)or to the confirmation that no applicable and effective replacement would be possible on AHM basis.The above resumes the d

141、iscussion of what is conducive in the end to the MRBR with its potential enhancement considering AHM capabilities.It is important to note that whereby the AHM path may not be found applicable and effective within the MRBR framework,the stakeholder(DAH)may still develop and offer AHM options outside

142、the MRBR.As part of the AMP the airline operator may decide to use such options or even pursue to develop them.The SAE Aerospace Council Technical Committees with AHM related focus(i.e.AISCSHM for aerospace structures,HM-1 for systems and E-32 for propulsion)released several materials to address sta

143、ndardized metrics,recommended practices and design requirements linked to the design approach and integration of vehicle health management systems(see references 7 to 12 in Appendix 2).Takeaway Aviation industry started its evolution towards AHM capability and integration,and is envisaging a breakth

144、rough in this journey by future pervasive availability of remote data and use of health-ready components/systems to enable reliable prognosis and prediction of their RUL.The industry incremental transition to AHM will be conducive to partial validation of recommended practices and standards through

145、legacy fleet retrofits before a new clean-sheet design of a complete AHM-ready aircraft type/model will emerge.20 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 5.Regulatory Balancing Act The role of Aviation Regulators in the AHM construct is covering all the typical aviatio

146、n industry certification,authorization,and oversight activities which ensure the operation of a safe and reliable civil aviation ecosystem.The opportunity which Regulators have for adopting an effective risk-based framework and guidance for AHM implementation is dependent on the timely harmonization

147、 between regulatory systems and the industry stakeholders leading the AHM evolution.IATA is at the forefront of advocating and pursuing such harmonization and,given its status of non-commercial and impartial airline industry association,is an active partner for AHM focused proceedings conducted by a

148、viation regulatory bodies present in the International Maintenance Review Board Policy Board(IMRBPB),ICAO Airworthiness Panel(AIRP)and Maintenance Management Team(MMT).This section is presenting some of the regulatory debated elements and highlights considerations which the Regulators are called to

149、ponder on in a timely manner as part of their AHM focused work with and guidance to industry entities.5.1.Addressing Necessity Integration of AHM within the aircraft maintenance activity must have direct or indirect approval/acceptance by the competent aviation authorities certifying/authorizing/lic

150、ensing and overseeing the products,organizations,personnel,processes and procedures involved.While the required effective correlation between the typical“Certification/Initial Airworthiness”and“Flight Standards/Continuing Airworthiness”parts of the regulatory house is not a novelty facing aviation a

151、uthorities,the details of a commensurate and risk-based action with AHM focus are sometimes challenging the customary conventions.This brings the opportunity of a data driven questioning each time a legacy approach to aircraft maintenance would be prone to AHM based evolution.Providing the SATAA cor

152、e of AHM with some specific additional regulatory boundaries and guidance is an incremental process for which the successful previous aviation exploit of developing and implementing ETOPS/EDTO is a valuable procedural precedent.The AHM construct is encompassing many widely recognized initiatives and

153、 functioning programs like:Aircraft Health Monitoring,Engine Health Monitoring,Structural Health Monitoring,Aircraft Condition Monitoring System,Engine Condition Monitoring,Rotorcraft Health and Usage Monitoring System.This legacy of achievements is spanning over a few decades and that should facili

154、tate a robust and timely differentiation between added value regulatory intervention and ineffective or over-bureaucratic regulatory red tape.A true AHM implementation involves crediting the right actors for executing decisional mechanisms that support the aircraft safe operation as effective as the

155、 legacy processes and procedures which they constitute an alternative to.5.2.Solving the AHM Puzzle There are numerous questions to answer in the context of defining and implementing the AHM path and they concern both the readiness of the present regulatory construct for the approach in general and

156、options for addressing the individual solutions in particular.21 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 It is important to raise the issues and ask the questions to incite the exploratory work with the Regulators even when acknowledged that a definitive answer would n

157、ot be practicable at the level of“one size fits all”generic discussion.The issues are mainly emerging from reviews and analysis of:Suitability and readiness of the legacy regulation for certification and continued airworthiness regarding AHM implications including the performant and secure data acqu

158、isition-transmission-analysis-storage.Eligibility or non-suitability of the AHM sequence to supplement,provide alternatives to or supersede partially or completely the aircraft maintenance tasks.Consequences/impact of AHM on allocation of initial and continuing airworthiness responsibilities between

159、 the DAH/OEM and the Airline Operator(including Engineering/CAMO and Maintenance/MRO related activities).The architecture of the AHM approach and its on-board/off-board aircraft partitioning.Building AHM with resources(i.e.,products,services,personnel)residing within or external to aircraft Technica

160、l Operations organizational layers(e.g.,Engineering,Maintenance and Supply Chain/Material Management)and even to customary aviation domain organizational layers.Addressing the transfer/portability of the aircraft asset maintenance between an AHM solution and a non-AHM(legacy)one:both in a temporary

161、scenario requiring continuity/recovery of maintenance operations(like a short-time unavailability of the AHM solution employed by the operator)and in a permanent transition(like an aircraft transfer to another airline)from an“AHM operator”to a“non-AHM”one.Figure 9:Pieces of the Puzzle Depending on t

162、he acceptance of AHM as an“evolutionary”step or viewing it as a“revolutionary”change in aircraft maintenance,a series of AHM specific or technical aviation broader subjects enter the regulatory focused discussion spectrum.Airline/Operator or DAH/OEM discussion is an area of recognition that,while th

163、ere are independent individual stakeholder attributes in AHM,the sought outcome can be achieved only by discharging the obligations of both 22 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 categories mentioned;the airline could pursue an AHM approach only to a limited extent

164、 if the aircraft structure/system/component is not designed and manufactured at a certain“AHM ready”level;the transfer of AHM work execution between the two stakeholders camps could take place but regulatory responsibility transfer needs clarification.On-Board or Off-Board debate is due to the limit

165、ed integration by the aircraft platform of the needed data processing and analysis which leads to the decision on the maintenance action;the typical SATAA is still involving major ground-based contribution in advance of the maintenance action itself;future technical developments may shift much of th

166、at and regulatory provisions should accommodate all scenarios.Qualify or Certify discussion acknowledges that,while many of the technical elements supporting the data collection and analysis are part of aircraft configuration and are certified as such via the aircraft certification process,the data

167、analysis may be the result of non-aviation traditional resources which lack an aviation certification;ground-based hardware and software involved in data analysis is“imported”to aviation;more parts of the maintenance action decision making reside with data analysts who are not(and should not be)nece

168、ssarily certified/licensed maintenance personnel.Aviation Source or COTS Source is linked to the previous theme by recognizing that,while there may be a need of verifiable status and traceability elements,a form of“qualification”construct should suffice and be accepted by Regulators;there are clear

169、cases when a risk-based rationale would indicate that a strict aviation“certification”process is not justified and its replacement with a“qualification”commensurate to the case would deliver the same safety benefits.Relying on AHM implementation for airworthiness determinations or maintenance progra

170、m adjustments requires regulatory authority acceptance and authorization.The required maintenance credits for the related AHM parts would be integral to the process.If operators use data for monitoring self-imposed tasks that have no influence on airworthiness,such express authorization may not be r

171、equired.For example,it is envisioned that for US-based operators,the FAA will grant maintenance program AHM authorization through Ops Spec D302“Integrated Aircraft Health Management(IAHM)Program”.The provision is mentioned in the draft Advisory Circular(AC)43-218“Operational Authorization of Integra

172、ted Aircraft Health Management Systems”.This publication,once sanctioned by the FAA,may provide a template for other national regulatory authorities to emulate.Another example of a recent development with relevance to AHM path is the FAA(AIR-621,AED)released generic“Issue Paper on Qualification of a

173、 Structural Health Monitoring System for Detection of Damage in Structure”available to interested applicants in connection with AC 25.571-1D.Examples of regulatory recognition of AHM precursors relevant to the AMP exist also in the form of references to Aircraft Health Monitoring and Engine Health M

174、onitoring in the Part-M and Part-CAMO issued by EASA.The regulatory issues linked to AHM should be considered in a timely manner by Civil Aviation Authorities.Such entities must instigate the establishment of an AHM approach governed by uniform ICAO-originated standards to eliminate variability and

175、ensure harmonization and consistency among national rulemaking,processes,procedures,and regulation mechanisms.While the aviation regulatory provisions are not called upon governing the commercial aspects of the developments they regulate,and nor should they attempt doing that,there are contextual el

176、ements regarding ownership and 23 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 intellectual propriety rights regarding data produced and exchanged for AHM purposes as well as the regarding algorithms to process that data.The Civil Aviation Authorities should be aware of suc

177、h aspects and consider if they are recognized and agreed to in a way that would not impede on the implementation and accountabilities of AHM stakeholders.Takeaway A risk-based approach should timely drive the rationale to determine if AHM specific regulatory provisions need to be established.Regulat

178、ors should be transparent and closely engage with Aviation Industry stakeholders to validate the need and to draft such provisions,as applicable.Regulatory guidance material is needed by AHM actors to drive their effort in a harmonized and level playing field across all aviation jurisdictions.Regula

179、tors should closely cooperate with Aviation Industry stakeholders when drafting such guidance.The development pace of the AHM path by Industry should instil a sense of urgency for Regulators in addressing the above.24 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 6.AHM Roadm

180、ap The AHM concept surpassed the phase of its brainstorming beginnings and,without denying the“in-flux”status for some of its features,is reaching a maturity level justifying the dynamics of implementation phase.This section presents several considerations relevant to mapping the implementation road

181、 of AHM.6.1.Starting Points The aviation industry has enacted in the last decades several successful aircraft structure and systems monitoring programs which are considered,in a significant measure,precursors of the integrated AHM pursued today.Monitoring of physical parameters like pressures,temper

182、atures,vibration,mechanical loads,electric loads/currents in a time series data flow which covers transitory as well as stabilized operation of aircraft systems/components is enabling operators to estimate degradation or detect a fault before a functional failure would generate operational disruptio

183、ns to require unscheduled maintenance corrective action.The main purpose of such monitoring programs was to enable a system of notifications and alerts which were tailored for triggering actions to improve the operator dispatch reliability or optimize the cost of maintenance and repairs.By far and l

184、arge they were not used as the sole source to determine aircraft system condition for safe operation.Such airworthiness determination was not permitted in the absence of another accepted practice use as well(e.g.,visual check or functional check).There is a limited number of one-off cases when aircr

185、aft health monitoring techniques were given the maintenance credit required to alter/replace a traditional industry-accepted practice.Nevertheless,the sizeable experience gathered by exercising the SATAA specific steps in the type of programs mentioned above(see also section 5)is of significant tran

186、sferable value to the integrated AHM model.6.2.Validation Gates and Criteria The validation gates and criteria must be set considering the requirements for design approval(residing with the DAH)and the operational authorization(residing with the Airline/Operator).In meeting both categories of requir

187、ements it should be made clear that the definition of the set of requirements in each category should be tailored to the content and complexity of the AHM implementation envisaged.A typical example of such tailoring would be the use for AHM purpose of data and information identical in origin(source)

188、/form/format with the one already employed in the control and oversight(including the FDE)of the aircraft system/equipment;this was already covered by certification of the aircraft design and,thus,additional design approval expectation based on its off-aircraft use for AHM could be questioned by the

189、 applicant.Obviously that any AHM dedicated system/component which is part of the aircraft certificated configuration will be submitted to the aircraft certification process specifics to the extent applicable to the said AHM dedicated system/component.The importance of an incremental progress toward

190、s establishing the AHM cannot be underestimated.This incremental approach is particularly important for the operational authorization as well as the AHM induction of“legacy aircraft types”.A clean-sheet design aircraft would give the opportunity of integrating the AHM readiness in the initially cert

191、ified configuration.25 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 6.3.Pursuing Implementation The considerations presented in this section sketch a roadmap of what a successful implementation of AHM in the airline industry should entail in the short,medium,and long-time h

192、orizon.Figure 10:Steps to Take for AHM Implementation 26 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 While each timing stage comprises identifiable prerequisites,which are a must in order to access the milestone deliveries,quantifying the timeline of each one of the three

193、time-horizons is inherently a challenging forecast.Such challenge is additionally compounded by the context in which the aviation industry in general,and the airline world in particular,started the 2020s decade with two years of unprecedented crisis during which existential priorities took their tol

194、l on AHM envisaged steps by each stakeholder category and individual entity.The good news would be that completing the short-term prerequisites is almost accomplished and checking the respective stage milestone achievements was already started by AHM early adopters in each stakeholder category.It is

195、 worth reminding some successful use cases and completed actions focused on implementation of AHM elements:Airline identification and prediction for aircraft defect management performed in-house or with OEM support(e.g.bleed air valves,flap skew sensors,filter condition monitoring,hydraulic level mo

196、nitoring)AMOC issued to AD provisions on the basis of AHM procedures,with appropriate end to end definition(including constraints,mitigating measures and analysis algorithm)to replace fixed periodicity requirements for SDI maintenance action(e.g.,engine HPT borescope inspection,pressure bulkhead NDT

197、)Proposal of revised PPH to support the IP-180 implementation in the aircraft type MRBR While AHM is mainly contemplated as an alternative at this time,its addressing could take place on applicability basis at operator level via customized solutions or at the fleet-wide global level via appropriate

198、DAH involvement;with the former having the potential of a more agile time-response to adoption of AHM,the latter will always be a guarantee for the AHM adoption coverage.Takeaway Airlines have a significant experience with AHM type of actions scoped to improve their individual aircraft operational r

199、eliability or to optimize the cost of individual aircraft maintenance and repairs.Incremental steps in adopting AHM should be timely progressed to the benefit of all stakeholders before the advent of the next clean-sheet design aircraft.The active sharing of experience and examples between AHM stake

200、holders should be incessantly pursued in all eligible fora with the view of a timely progress in this field benefitting Industry and Regulators alike.27 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 7.Conclusions A significant body of knowledge and experience emerged from ye

201、ars of aircraft health and trend monitoring used to enhance aircraft dispatch reliability(DR)rates.The span of successful use cases,encompassing aircraft systems(including propulsion systems)and aircraft structure,constitutes a solid basis and strong motivator for developing the AHM path.This would

202、be an alternative applicable to many of the aircraft maintenance tasks and lead to a change in the typical form and significance of execution thresholds and periodicity.Introduction of the AHM option alternative,as an opportunity and not as an obligation,is needed to attain the scale of economics po

203、tentially offered by the concept of aircraft“Maintenance of Tomorrow”in which true aircraft condition-based maintenance(CBM)would rely on the implementation of both predictive and prescriptive analytics capabilities.There are aircraft certification aspects and continued airworthiness elements which

204、must be addressed to fully realize the attainable benefits of AHM.They require a phased and simultaneous timely evolution of the deliverables by aviation industry and regulatory entities alike.This can be achieved with a prompt recognition of and commitment to a realistic sense of urgency by all sta

205、keholders involved in the AHM related work.Providing an AHM option in future MSG-3 methodology will compel the timely motivation for new policies,derivative procedures,and technology benefiting all air transport industry stakeholders.This may precipitate a methodological upgrade establishing the bas

206、is of a future MSG-4 task development philosophy construct.Using AHM data and analysis capabilities to define alternative means to accomplish a“classic”preventive maintenance task is the next practicable opportunity to further enhance aircraft availability.The approach would also require an appropri

207、ately revised set of criteria in the traditional area of No Fault Found(NFF)categorization used by maintenance providers,since an operator may employ AHM prediction to remove aircraft components prior to their in-service failure.The AHM approach impact on the technical operations commercial practice

208、s and supply chains must be considered as well.Such considerations will potentially reshape the terms of performance agreements both at the product(e.g.,aircraft,engines)and component levels,and also trigger a reconsideration of how spare parts inventories are defined and maintained to support aircr

209、aft fleet operations.Benefiting from automation prone sequences of AHM,including prognostics active reliance on artificial intelligence(AI)and machine learning(ML)techniques coupled with digital twinning of aircraft assets,constitute a priority for viably achieving AHM scalability.The necessary leve

210、l of digital transformation inherently requires addressing the data ownership and cybersecurity concerns;they are altogether topics of a different important discussion.28 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 Appendix 1 Abbreviations Abbreviation Source Terminology A

211、D Airworthiness Directive AED Aircraft Evaluation Division(FAA)AHM Aircraft Health Management,Aircraft Health Monitoring AI Artificial Intelligence AIR Aircraft Certification Service(FAA)AIRP Airworthiness Panel(ICAO)AISCSHM Aerospace Industry Steering Committee on Structural Health Monitoring AMOC

212、Alternative Means Of Compliance AMP Aircraft Maintenance Program CAMO Continuing Airworthiness Management Organization CBM Condition Based Maintenance CDL Configuration Deviation List CM Condition Monitoring COTS Commercial(available)Off-The-Shelf DAH Design Approval Holder DR Dispatch Reliability E

213、ASA European Union Aviation Safety Agency EDTO Extended Diversion Time Operations EIS Entry Into Service EMG Engineering and Maintenance Group(IATA;it became TOWG as of 2021)ETOPS Extended Range Twin-Engine Operations FAA Federal Aviation Administration FDE Flight-Deck Effect FEC Failure Effect Cate

214、gory FRACAS Failure Reporting,Analysis and Corrective Action System FTOPS Flight and Technical Operations(IATA)HPT High Pressure Turbine HT Hard Time IATA International Air Transport Association IAHM Integrated Aircraft Health Monitoring ICAO International Civil Aviation Organization IMRBPB Internat

215、ional Maintenance Review Board Policy Board IP Issue Paper KPI Key Performance Indicator LLP Life Limited Part 29 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 MEL Minimum Equipment List ML Machine Learning MMT Maintenance Management Team MPIG Maintenance Program Industry Gr

216、oup MRBR Maintenance Review Board Report MREPS Maintenance Reports MRO Maintenance,Repair and Overhaul MSI Maintenance Significant Item MSG Maintenance Steering Group NDT Non Destructive Test NFF No Fault Found OC On Condition OEM Original Equipment Manufacturer PIREPS Pilot Reports PPH Policy and P

217、rocedures Handbook P to F Potential to Failure RUL Remaining Useful Life SATAA Sense,Acquire,Transfer,Analyze and Act SDI Special Detailed Inspection SF Science Fiction TC Type Certificate TOWG Technical Operations Working Group(IATA;former EMG)UBL Usage-Based Lifing 30 From Aircraft Health Monitori

218、ng to Aircraft Health Management Feb 2022 Appendix 2-Suggested Readings 1“Aircraft Operational Availability”1st Edition,2018 International Air Transport Association(IATA)2 Proceedings of“5th Paperless Aircraft Operations and RFID Conference”2018 IATA 3 Proceedings of“14th Maintenance Cost Conference

219、”2018 IATA 4“ATA MSG-3 Operator/Manufacturer Scheduled Maintenance Vol 1 Fixed Wing Aircraft”Revision 2018.1-Airlines for America 5“IP180-Aircraft Health Monitoring Integration in MSG-3”2018 International MRB Policy Board 6“AC 43-218-Operational Authorization of Integrated Aircraft Health Management

220、 Systems”FAA Draft for Public Comments 2019 7“ARP6803-IVHM Concepts,Technology and Implementation Overview”2016 SAE International 8“ARP5987-A Process for Utilizing Aerospace Propulsion Health Management Systems for Maintenance Credit”2018-SAE International 9“ARP6461-Guidelines for Implementation of

221、Structural Health Monitoring on Fixed Wing Aircraft”Rev A-2021 SAE International 10“ARP6407 IVHM Design Guidelines”2019-SAE International 11“ARP6883 Guidelines for Writing IVHM Requirements for Aerospace Systems”2019-SAE International 12 “JA6268 Design&Run-Time Information Exchange for Health-Ready

222、Components”2018 SAE International 13 “Aerospace Predictive Maintenance:Fundamental Concepts”Charles E.Dibsdale SAE International 2020 14 “Reliability-centred Maintenance”Second Edition,1997 John Moubray 15 “Aeronautical Design Standard Handbook ADS-79E-HDBK-Condition Based Maintenance for US Army Ai

223、rcraft”Dec 2015 31 From Aircraft Health Monitoring to Aircraft Health Management Feb 2022 Appendix 3-Acknowledgements This White Paper presents elements highlighted during the IATA Flight and Technical Operations(FTOPS)teams engagement on the AHM subject since late 2015.While these considerations em

224、erged from the FTOPS perspective on the presented topics,they would have not been possible without the multiple meetings and discussions on the subject that took place in bilateral or multilateral settings,primarily with Airlines,Aircraft OEMs,Engine OEMs and Civil Aviation Authorities,also involvin

225、g other stakeholders throughout the aviation industry.Enumerating the individual partners of dialogue engaged by IATA on the AHM subject would generate a long and likely incomplete list.A sincere thank you is addressed to all participants in the following forums,with high appreciation for the open d

226、ebates,shared insights and productive work made possible since 2015:IATA Technical Operations Working Group/Engineering and Maintenance Group;Maintenance Programs Industry Group;SAE Committees for:o Aerospace Propulsion Systems Health Management,o Integrated Vehicle Health Management,o Aerospace Industry Steering on Structural Health;International MRB Policy Board;Maintenance Management Team,and ICAO Airworthiness Panel This White Paper was authored by:Dragos Budeanu,IATA budeanudiata.org Chris Markou,IATA markouciata.org