Technical Advisory Board On The Design Change To The B737 .
Report to Executive Director, FAA Aircraft Certification Service:Technical Advisory Board on the Design Change to theB737 MAX Maneuvering Characteristics AugmentationSystemFinal Report:November 18, 2020
Technical Advisory Board on the Design Change to the B737 MAX Maneuvering CharacteristicsAugmentation SystemExecutive SummaryBackgroundThe Federal Aviation Administration (FAA) is overseeing The Boeing Company’s(Boeing) design change to the maneuvering characteristics augmentation system (MCAS)on Boeing Model 737-8 and 737-9 airplanes (known as B737 MAX airplanes). MCAS ispart of the speed trim system (STS) that enhances handling qualities in the pitch axis incertain speed/angle of attack regimes. Configuration changes (engine size and placement)unique to the B737 MAX led to the MCAS design to maintain consistent handlingcharacteristics with earlier versions of the Boeing B737 family.On October 29, 2018, Lion Air flight 610 (JT610), a Boeing Model 737-8 airplane,crashed approximately twelve minutes after takeoff in Jakarta, Indonesia. On March 10,2019, Ethiopian Airlines flight 302 (ET302), also a Boeing Model 737-8 airplane,crashed approximately six minutes after takeoff in Addis Ababa, Ethiopia. The B737MAX automated flight control system is an area of interest in both accidents. The FAAdetermined that the implementation of a Technical Advisory Board (TAB), consisting ofan independent team of aircraft safety, system, and flight test experts was necessary toevaluate the redesign of the automated flight control system/MCAS. The TAB used anestablished process to provide an independent technical evaluation of the B737 MAXMCAS.Technical Advisory Board Review TasksThe TAB was tasked to evaluate Boeing’s redesign of the MCAS. The purpose was todirectly inform the FAA’s decision making on MCAS approval and return of the B737MAX airplane to service. These tasks included examining and dispositioning relevantfacts, including all identified unsafe conditions regarding the JT610 and ET302 accidents,in accordance with 14 CFR 21.21 (which relates to the issuance of type certificates). Thisevaluation encompassed several broad areas, including the following: A review of all MCAS continued operational safety data and information gatheredto date; A review of the technical approach for key design features that meets thecompliance requirements set forth by the type certificate; A review of the item requirements and design, as defined under the certificationstandard, to ensure that all items have been complied with, includingdispositioning of any open problem reports; A review of the failure modes of the redesign, to show that they are reasonablymanageable by line pilots; and A review to ensure that proposed training programs for the redesign areappropriate, including a review of the work done by the Flight StandardizationBoard (FSB).The TAB evaluated the B737 MAX MCAS design changes by conducting designreviews, procedure evaluations, and training assessments. These evaluations wereii
Technical Advisory Board on the Design Change to the B737 MAX Maneuvering CharacteristicsAugmentation Systemconducted, taking into consideration representative flight conditions while maneuveringthroughout the normal, operational, and limit flight envelopes that could be simulated inthe Boeing engineering simulator (eCAB). The TAB evaluations also included desktopdata reviews, eCAB testing, and training development reviews.Results – Return-to-Service Action ItemsThe TAB found that the MCAS design changes are compliant and safe to support a returnto service of the B737 MAX. The TAB’s findings were contingent on the satisfactoryresolution of the following action items. These action items were completed by theBoeing Aviation Safety Oversight Office (BASOO), Boeing, or the FAA’s AircraftEvaluation Group (AEG), as noted.These action items were not based on the BASOO certification processes, as the TABevaluation was conducted independent of the BASOO certification process and prior tothe completion of the BASOO certification data review activities.ActionItem1Description of ActionAs an extension of the TAB review, complete an audit ofBoeing’s development assurance process as documented intheir development assurance plan.ResponsibleGroupBASOOAction item closed. Audit completed. The TAB evaluatedand accepted the Development Assurance AccomplishmentSummary document.2Submit further analysis and test data to ensure properfunctional integration of the spoiler system with the trimsystem and MCAS to include a top down assessment, orequivalent, which verifies the bottom up single and multiplefailure (S&MF) analysis adequately covered combinationsof speed trim system and spoiler system failures not shownto be extremely improbable.BoeingAction item closed. Based on TAB review of the Boeingcloseout memorandum and associated reference documents.Discussion in a meeting between Boeing and the TAB onSeptember 23, 2019 led to the creation of a document toexplain how Boeing’s Airplane Functional HazardAssessment (AFHA) and System Functional HazardAssessments (SFHAs) for the B737 MAX work together toform a robust top-down analysis for airplane and systemlevel functions, and how that top-down analysis is verifiedby the bottom-up S&MF analysis. The TAB evaluated andaccepted the analysis.iii
Technical Advisory Board on the Design Change to the B737 MAX Maneuvering CharacteristicsAugmentation SystemActionItem3Description of ActionSubmit the final version of the MCAS fault trees.ResponsibleGroupBoeingAction item closed. Boeing provided the final version of theintegrated system safety assessment (iSSA) dated August 25,2020, which was accepted by the TAB.4Submit the complete root cause analysis for the AutoStabilizer Trim Monitor error in the fault tree for the LowAltitude Stabilizer Runaway failure condition (designescape).BoeingAction item closed. Boeing provided close out coordinationsheet, June 19, 2019, which references the root causeanalysis. The TAB reviewed and accepted the root causeanalysis.5Boeing to address the FCC CPU and memory postulatedfailure issue discovered during eCAB certification testing.BoeingAction item closed. The TAB evaluated new monitors todetect failures in P12.1.2 and evaluated thresholds byconducting eCAB testing. Boeing provided iSSA withmonitor coverage dated August 25, 2020. The TABevaluated and accepted the iSSA.6Ensure the Speed Trim Fail procedure in the QuickReference Handbook (QRH) encompasses both the speedtrim function and the MCAS function.Boeing/AEGAction item closed. Boeing has incorporated changes in theBoeing QRH. The TAB has evaluated the changes to theBoeing QRH and found them acceptable.7Add angle of attack (AOA) DISAGREE to the list ofadditional information as possible evidence of anAIRSPEED UNRELIABLE condition in the QRH.Boeing/AEGAction item closed. Boeing has incorporated changes in theBoeing QRH. The TAB has evaluated the changes to theBoeing QRH and found them acceptable.iv
Technical Advisory Board on the Design Change to the B737 MAX Maneuvering CharacteristicsAugmentation SystemActionItem8Description of ActionResponsibleGroupAEG to discuss with the Certification Management TeamBoeing/AEG(CMT) and other stakeholders to consider incorporating IASDISAGREE and AOA DISAGREE into Airspeed UnreliableChecklist so that it is titled Airspeed Unreliable or IASDISAGREE or AOA DISAGREE, similar to the B747checklist.Action item closed. The TAB concluded that with theenhanced training package, pilots will be able to successfullycomplete the separate IAS DISAGREE and AOADISAGREE NNCs. This was also validated in the JointOperations Evaluation Board (JOEB) activity and supportedby B737NG service history. The TAB observes that there isa potential for confusion and misunderstanding when QRHs(or other documents) constructed by individual CAAs oroperators differ from the AFM. The TAB observes thatguidance on this subject in AC 25.1581-1 conflicts with therules in 14 CFR 25.1581 through 25.1587, and that clearingup this conflict would improve oversight and reduceconfusion.9Submit the final version of Level B training (i.e., computerbased training) to the TAB for review.Boeing/AEGAction item closed. TAB reviewed all level B training andBoeing incorporated appropriate changes to the level Btraining as documented in the FSB report. The TAB notedthat FSB report Appendix 7 requires a one-time full flightsimulator training profile. The TAB reviewed that one-timesimulator training and found it acceptable.10Identify if special emphasis training for B737 series trimwheel forces awareness (including manual trim forcerequirement) is appropriate.Boeing/AEGAction item closed. Boeing provided and the TAB acceptedBoeing Report, 737-8/-9 Stabilizer Trim Wheel Forces, andtrim awareness training per FSB report.v
Technical Advisory Board on the Design Change to the B737 MAX Maneuvering CharacteristicsAugmentation SystemActionItem11Description of ActionResponsibleGroupChange STABILIZER TRIM to SPEED TRIM in the ATA27 Flight Control row, remarks column contained in theFlight Standardization Board Report (FSBR) differencestable, FROM BASE AIRCRAFT B-737-800 TO RELATEDAIRCRAFT B-737-8.Boeing/AEGAction item closed. FAA incorporated the intent of thechange as documented in the FSB report appendix 3Differences Tables/Design ATA 22 Autoflight.Results – Future Action ItemsAdditionally, the TAB identified eight future action items that should be addressed byBoeing, the Seattle Aircraft Certification Office Branch (SACO), BASOO, Civil AviationAuthorities (CAAs), or AEG in a timely manner, as determined by the FAAAdministrator. These future action items are not a prerequisite for returning the aircraft toservice. The reason that these future action items are not required to be completed prior toreturning the aircraft to service is because they are broader in scope than the B737 MAXMCAS enhancement action items. Additionally, they generally apply to the B737 NGs(Boeing Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes are knownas Next-Generation, or B737 NG airplanes), which have over 190,000,000 flight hours ofunaffected service without the B737 MAX MCAS design features.FutureAction Item1Description of Future ActionProvide the root cause analysis for whyimplementation of the “AOA DISAGREE”message did not meet the design requirements. The“AOA DISAGREE” message was supposed to bestandard on all airplanes. However, the “AOADISAGREE” message was an option that was tiedto the AOA Indicator option.ResponsibleGroup(s)BoeingAction item closed. Boeing provided close outcoordination sheet, dated November 5, 2019 whichreferences the root cause analysis. The TABreviewed and accepted the root cause analysis.vi
Technical Advisory Board on the Design Change to the B737 MAX Maneuvering CharacteristicsAugmentation SystemFutureAction Item2Description of Future ActionWork with the head up display (HUD)supplemental type certificate (STC) holder toinclude the requirement for the B737 MAX HUDSTC to include the “AOA DISAGREE” message.ResponsibleGroup(s)SACOAction item closed. SACO confirmed STC designchange during B737-10 certification. Retroactiveincorporation will be based on SACO correctiveaction review board (CARB) process.3Prioritize the indicated airspeed (IAS) DISAGREEalert appropriately. This will assist pilots inprioritizing their actions in the high-workloadenvironment that could result from an AOADISAGREE, such as during takeoff, climb-out,approach and landing.BoeingAction item open: Requires a Boeing commitmentfor a longer-term solution.4Add the notes from the QRH Stab Trim Inopprocedure to the Runaway Stabilizer procedure.Boeing/AEGAction item closed: Boeing has incorporatedchanges in the Boeing QRH. The TAB hasevaluated the changes to the Boeing QRH andfound them acceptable.5Evaluate the manual trim wheel control forces inBoeing,the B737 MAX full flight simulator (FFS) toBASOO, AEG,determine if exceptional pilot strength, alertness, or or bothskill is required for controllability andmaneuverability of the aircraft.Action item closed: Boeing provided and the TABreviewed/accepted Boeing Report, 737-8/-9Stabilizer Trim Wheel Forces to verify exceptionalpilot strength, alertness, or skill is not required forcontrollability and maneuverability within thecertificated envelope of the aircraft.vii
Technical Advisory Board on the Design Change to the B737 MAX Maneuvering CharacteristicsAugmentation SystemFutureAction Item6Description of Future ActionBoeing to add step (if necessary) autothrottledisengage in Stabilizer Trim Inoperative checklistin QRH.ResponsibleGroup(s)BoeingAction item open: Boeing should evaluate thisissue further via normal process post RTS todetermine if adding a step about autothrottle usageis warranted.7Analyze the initial, recurrent, transition, andupgrade training needed to provide the proficiencyand currency requirements for air carriers. Identifythe kinds of flightcrew interactions with theequipment that can be reasonably expected inservice by qualified flightcrew trained in their use.InternationalCivil AviationOrganization(ICAO) orCAAs, or bothAction item open: FAA should develop an actionplan to engage ICAO and CAAs.8At the earliest regular training event, pilots of allB737 series airplanes should receive specialemphasis training on trim system understanding,awareness, and use. Consideration should be givento broadening this training recommendation topilots of all transport category airplanes.FAA/CAAs/IndustryAction item open: TAB reviewed and acceptedspecial emphasis training on trim systemunderstanding, awareness, and use on the B737series airplanes as documented in the FSB report.FAA to follow-up to determine if special emphasistraining should be given to all transport airplanestypes and, if so, establish the necessarycommunications via inspector guidance duringtraining program approval.viii
Technical Advisory Board on the Design Change to the B737 MAX Maneuvering CharacteristicsAugmentation SystemTable of ContentsExecutive Summary . iiBackground . iiTechnical Advisory Board Review Tasks. iiResults – Return-to-Service Action Items . iiiResults – Future Action Items. viTable of Contents . ixList of Figures . ixTechnical Advisory Board Process . 11.1Technical Advisory Board Team Bios . 1Evaluation of Redesign of the B737 MAX MCAS . 92.1Evaluation Scope . 92.2Design Evaluation . 102.2.1Systems Engineering Assessment . 102.2.2System Safety Assessment . 112.2.3Software Assessment. 122.2.4Flight Controls and Flight Deck Interface Assessment . 142.2.5Stabilizer Trim Cutout Switches Assessment . 172.2.6CPU and Memory Catastrophic Failures . 182.3Procedures Evaluation . 182.4Training Evaluations . 222.5Conclusion . 26Appendix A: Documentation . 27Appendix B: Acronyms . 29List of FiguresFigure 1. B737 MAX Primary Flight Display . 15Figure 2. B737 Quick Reference Handbook – IAS DISAGREE Procedure . 18Figure 3. B737 Quick Reference Handbook – Airspeed Unreliable Procedure . 19Figure 4. Table from FSBR to be revised . 25ix
Technical Advisory Board on the Design Change to the B737 MAX Maneuvering CharacteristicAugmentation SystemTechnical Advisory Board ProcessThe TAB is an independent team of experts who are not routinely involved incertification of the product being certificated. The TAB evaluates efforts by the cognizantFAA certification office and the applicant associated with a design or redesign of asystem to inform agency decision making as appropriate to the certification issue. TheTAB challenges the assumptions and design decisions made by the applicant andoverseen by the cognizant FAA certification office. The TAB may examine data andother information as extensively as necessary to conduct the following activities:1.1 Review any design changes and the overall approach to demonstrate compliancewith regulatory standards; Review available data related to the design change to confirm that it minimizesexpected in-service failures; Review relevant failure modes that can affect the pertinent system(s) and confirmthat the design change(s) mitigates the hazards; Review approach for software certification, including definition and execution ofrequirements with relevant suppliers and disposition of software problem reports; Review training program changes to confirm outcomes of the FlightStandardization Board evaluation; and Submit a final report and recommendation to the Executive Director of theAircraft Certification Service.Technical Advisory Board Team BiosRegina Houston – Chief of the Aviation Safety Management Systems Division, andActing Chief of the Safety Information Systems Division, Volpe NationalTransportation Research CenterRegina Houston joined the Volpe National Transportation Research Center in 1991where she is Chief of the Aviation Safety Management Systems Division and ActingChief of the Safety Information Systems Division. Ms. Houston has over 35 years ofexperience in research and development of automation for transportation safety. Duringher most recent 25 years, Ms. Houston has focused on the aviation domain. She isrecognized for her expertise in safety management systems and the principals of systemsafety. Ms. Houston has extensive experience in re-engineering and aligning automatedsystems, models and simulations to support changes in aviation business processes,policy and regulations; and evolving transportation safety goals and objectives. She oftenserves as a subject matter expert to assess and develop integrated risk profile models andassist aviation safety inspectors in risk-based decision making.Ms. Houston was recognized for her work in aviation safety by receiving the U.S.Department of Transportation Secretary’s Award for Excellence and the Dr. Frank F.C.Tung Award. She is also the recipient of the United States Department of Tra
(Boeing Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes are known as Next-Generation, or B737 NG airplanes), which have over 190,000,000 flight hours of unaffected service without the B737 MAX MCAS design features.
May 02, 2018 · D. Program Evaluation ͟The organization has provided a description of the framework for how each program will be evaluated. The framework should include all the elements below: ͟The evaluation methods are cost-effective for the organization ͟Quantitative and qualitative data is being collected (at Basics tier, data collection must have begun)
Silat is a combative art of self-defense and survival rooted from Matay archipelago. It was traced at thé early of Langkasuka Kingdom (2nd century CE) till thé reign of Melaka (Malaysia) Sultanate era (13th century). Silat has now evolved to become part of social culture and tradition with thé appearance of a fine physical and spiritual .
On an exceptional basis, Member States may request UNESCO to provide thé candidates with access to thé platform so they can complète thé form by themselves. Thèse requests must be addressed to esd rize unesco. or by 15 A ril 2021 UNESCO will provide thé nomineewith accessto thé platform via their émail address.
̶The leading indicator of employee engagement is based on the quality of the relationship between employee and supervisor Empower your managers! ̶Help them understand the impact on the organization ̶Share important changes, plan options, tasks, and deadlines ̶Provide key messages and talking points ̶Prepare them to answer employee questions
Dr. Sunita Bharatwal** Dr. Pawan Garga*** Abstract Customer satisfaction is derived from thè functionalities and values, a product or Service can provide. The current study aims to segregate thè dimensions of ordine Service quality and gather insights on its impact on web shopping. The trends of purchases have
Chính Văn.- Còn đức Thế tôn thì tuệ giác cực kỳ trong sạch 8: hiện hành bất nhị 9, đạt đến vô tướng 10, đứng vào chỗ đứng của các đức Thế tôn 11, thể hiện tính bình đẳng của các Ngài, đến chỗ không còn chướng ngại 12, giáo pháp không thể khuynh đảo, tâm thức không bị cản trở, cái được
Le genou de Lucy. Odile Jacob. 1999. Coppens Y. Pré-textes. L’homme préhistorique en morceaux. Eds Odile Jacob. 2011. Costentin J., Delaveau P. Café, thé, chocolat, les bons effets sur le cerveau et pour le corps. Editions Odile Jacob. 2010. Crawford M., Marsh D. The driving force : food in human evolution and the future.
Le genou de Lucy. Odile Jacob. 1999. Coppens Y. Pré-textes. L’homme préhistorique en morceaux. Eds Odile Jacob. 2011. Costentin J., Delaveau P. Café, thé, chocolat, les bons effets sur le cerveau et pour le corps. Editions Odile Jacob. 2010. 3 Crawford M., Marsh D. The driving force : food in human evolution and the future.
