Originally Posted by cappt
(Post 10566609)
Putting it through a complete flight test program could take a year or more realistically. Euro airlines should be looking for alternative aircraft. The last slide in the document contains:- Flight tests on a modified B737 max [one full week - at Boeing Flight Test Center] - MCAS operations (nominal behavior) - Flight without MCAS (including high speed turns and stall) - Scenario of stabiliser runaway (uncommanded MCAS activation, manual trim wheel forces) - Approach to stall with autopilot engaged |
Originally Posted by jimjim1
(Post 10566524)
Presentation to European Parliament by the Executive Director of EASA
3 Sept 2019 A LOT of attention on the MAX. https://www.europarl.europa.eu/cmsda...y-original.pdf https://www.europarl.europa.eu/ep-li...COMMITTEE-TRAN Press play icon on video Mr Ky speaks as follows 10:26 Mr Ky General topics 10:35:11 737 MAX 10:46:19 End of Mr Ky presentation Questions by Members 11:28:24 Responses by Mr Ky 11:57 Additional questions and responses and chair comments 12:02 End I made some headline notes through the video - No idea if they will interest anyone but electrons are quite cheap. # # # # # # # # 10:25 CHAIR Introduction 10:26 Mr Ky Think Mr Ky spoke in English. Some speakers are simultaneously translated. 10:35:11 737 MAX 10:46:19 End of Mr Ky presentation Questions/Comments from Members 10:52:35 BREXIT FAA Relationship with FAA Ricardo report - posting of workers, bogus self employed, use of 3rd world, use of secondment Flight time limitations Maybe something earlier too - 737 MAX flight paths? BREXIT Green air travel - biofuels Cyber security Drones (Gatwick, frankfurt disruption Smartwings - one engine Green air travel MAX earlier pilot indications - pilot experience MAX FAA delegation, does EASA do it too? does China do it. Cyber security Social dimension - bogus self employed, precarious unstable work, not to be a danger to flight? Green air travel - ultra fine particles and human health A330neo - poor cabin air Electric aircraft - green approach Drones - international agreements, noise (other countries have air taxis:-) 11:21 Passenger behaviour CHAIR 3% of global emissions (guess CO2) - not reducing emissions What is the alternative to fossil fuels? "Positive Fuels" How did you calculate carbon footprint for Eco label. Pilot stress (unspoken reference to european airline pilot suicide) BREXIT (Spain) Digitalisation objective Drones (licencing), flying taxis 11:28:24 Responses by Mr Ky BREXIT 11:33 FAA 737 MAX International report in next week on What went wrong vis a vis FAA/Boeing. EASA doesn't delegate so freely - more structured FAA relationship in the future Social re- safety Green Supersonic MUST be quieter than existing aircraft on take-off 5 SST projects in progress in USA Drones - Google wings has been delivering parcels for last two years in Canberra - noise complaints Cyber A330neo cabin air Smartwings single engine - says ok. crew get to decide suitable airport 11:55 MAX No timeline for return to service FAA 11:57 /Ky More questions from Committee Brexit Pilot fatigue Mr Patrick Ky re-response Brexit Pilot fatigue 12:01 Chair Social 12:03 END |
Originally Posted by OldnGrounded
(Post 10566151)
The link is to a paywalled site and not everyone here is a subscriber to that periodical. So, if you want that article to be discussed, please summarize the relevant points.
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Great job Jimjim1 !
Thanks for that |
Some EASA slides re MAX return to service: European Parliament
Originally Posted by jimjim1
(Post 10566524)
Presentation to European Parliament by the Executive Director of EASA
3 Sept 2019 A LOT of attention on the MAX. https://www.europarl.europa.eu/cmsda...y-original.pdf Return to Service - EASA conditions p 11 Letter sent to the FAA on April 01, 2019. 4 conditions: 1. Design changes proposed by Boeing are EASA approved (no delegation to FAA) 2. Additional and broader independent design review has been satisfactorily completed by EASA 3. Accidents of JT610 and ET302 are deemed sufficiently understood 4. B737 MAX flight crews have been adequately trained EASA design review p 12 Objective: to ensure that no similar weaknesses in the design are present in the other (safety critical) areas of the 737 MAX design. Activities are being carried out on the Flight Control System and all associated functions/systems including but not limited to the following: displays, alerting system, autopilot and air data system. - Review of Functional Hazard Assessments and Safety Analysis - Review of Development Assurance process - Review of Flight Controls and Autopilot architecture and logics - Review of Human Factors aspects - Review of the methodology applied for the assessment of the Crew Training needs EASA activities p 13 EASA PROPRIETARY – Do not disclose without EASA consent - Unprecedented level of effort, involving around 20 multi-disciplinary experts, including test pilots and engineers, 2-3 weekly web- based meetings with Boeing, review of 500+ documents and actions - EASA requirements for flight/Simulator evaluation communicated on May 22. 70 test points requested to be evaluated, covering: - Normal operations (identification of MCAS operation) - Abnormal operations (AoA failures, stabiliser runaway, MCAS inoperative,…) - Simulators evaluation performed in June and July. EASA findings p 14 Significant technical issues: - Lack of exhaustive monitoring of the system failures resulting in a stabiliser runaway - Too high forces needed to move the manual trim wheel in case of a stabiliser runaway - Too late disconnection of autopilot near stall speed (in specific conditions) - Too high crew workload and risk of crew confusion in some failure cases, especially Angle of Attack single failure at take-off Findings communicated to Boeing and FAA in July 2019 p 15 in image below https://cimg7.ibsrv.net/gimg/pprune....3ac3bebb5b.png Next major milestones p 16 EASA PROPRIETARY – Do not disclose without EASA consent - Safety assessment of the new design changes proposed by Boeing, including operational procedures - Human factor evaluation and functional tests of the new software - Flight tests on a modified B737 max [one full week - at Boeing Flight Test Center] -- MCAS operations (nominal behavior) -- Flight without MCAS (including high speed turns and stall) -- Scenario of stabiliser runaway (uncommanded MCAS activation, manual trim wheel forces) -- Approach to stall with autopilot engaged - Crew Training requirements, in particular using Computer Based Training or Simulator - Coordination with EASA Member States on Return to Service actions Flight tests on a modified B737 max [one full week - at Boeing Flight Test Center] - MCAS operations (nominal behavior) - Flight without MCAS (including high speed turns and stall) - Scenario of stabiliser runaway (uncommanded MCAS activation, manual trim wheel forces) - Approach to stall with autopilot engaged |
Originally Posted by jimjim1
(Post 10566617)
A one week flight test program is mentioned. The first would be technical flights to assess things like aerodynamic stability without MCAS engaged and yes these should be carried out by professional test pilots. But the other flight testing is that which needs to be done to ascertain what level of training will be required for new MAX pilots on the modified model. This will require line pilots and preferably those who are 737 rated but with no experience on the MAX. After all, these will be the bulk of the pilots who will end up flying the MAXs parked at Renton and elsewhere. |
Originally Posted by Speed of Sound
(Post 10566762)
(...) But the other flight testing is that which needs to be done to ascertain what level of training will be required for new MAX pilots on the modified model. This will require line pilots and preferably those who are 737 rated but with no experience on the MAX. |
Originally Posted by jimjim1
(Post 10566639)
Flight tests on a modified B737 max [one full week - at Boeing Flight Test Center] - MCAS operations (nominal behavior) - Flight without MCAS (including high speed turns and stall) - Scenario of stabiliser runaway (uncommanded MCAS activation, manual trim wheel forces) - Approach to stall with autopilot engaged It's not clear what "uncommanded MCAS activation" means. Do they mean MCAS is activated even when the FCC is receiving consistent AoA values below the activation threshold? If so, how do they do this in a flight test? Are they going to fly an airplane with intentionally corrupted memory, which is what they apparently simulated in the EASA-requested simulator scenarios in July? Why does the uncommanded MCAS activation scenario involve "manual trim wheel forces"? By now, every 737 pilot in the world must know (even if they didn't know after the Emergency AD) that the correct response to an incorrect MCAS activation is to fully neutralize control forces using MET and THEN place the switch in the CUT-OUT position. Doesn't requiring demonstration of the manual trim wheel as a re-certification requirement rely on the assumption that pilots still cannot be relied upon to perform this procedure and will still CUT-OUT electric trim with the airplane in an out-of-trim condition? What is the regulatory basis for demonstrating recovery with a manual trim wheel when the published recovery procedure is to use MET before CUT-OUT? Obviously, fully FBW systems don't have a manual wheel and rely entirely on electronic controls to recover from a FCC-induced runaway trim condition. Why is the use of MET in the 737 different? We know, based on the ET302 accident, that the manual trim wheel cannot be used to re-trim from certain trim positions beyond certain airspeeds. Presumably, EASA re-certification is going to require successful use of the manual trim wheel up to some lesser degree of out-of-trim/airspeed condition. Is there a regulatory basis for deciding what that condition must be? |
Originally Posted by Notanatp
(Post 10566875)
Doesn't requiring demonstration of the manual trim wheel as a re-certification requirement rely on the assumption that pilots still cannot be relied upon to perform this procedure and will still CUT-OUT electric trim with the airplane in an out-of-trim condition?
Now how does a crew discover that the trim is misbehaving, requiring this specific procedure ? How long has a crew before things get out of hands ? Is the 737 MAX certifiable in this respect ? To date Boeing doesn't seem to have come up with a satisfying answer. In the eye of the EASA, at least. |
Originally Posted by Notanatp
(Post 10566875)
By now, every 737 pilot in the world must know (even if they didn't know after the Emergency AD) that the correct response to an incorrect MCAS activation is to fully neutralize control forces using MET and THEN place the switch in the CUT-OUT position. Doesn't requiring demonstration of the manual trim wheel as a re-certification requirement rely on the assumption that pilots still cannot be relied upon to perform this procedure and will still CUT-OUT electric trim with the airplane in an out-of-trim condition?
Disengage autopilot and control airplane pitch attitude with control column and main electric trim as required. If relaxing the column causes the trim to move, set stabilizer trim switches to CUTOUT. If runaway continues, hold the stabilizer trim wheel against rotation and trim the airplane manually. |
Originally Posted by OldnGrounded
(Post 10566151)
The link is to a paywalled site and not everyone here is a subscriber to that periodical. So, if you want that article to be discussed, please summarize the relevant points.
https://www.flightglobal.com/news/ar...llenge-460726/ |
Originally Posted by DaveReidUK
(Post 10566887)
No, it's simply conforming to the provisions of the AD:
>If relaxing the column causes the trim to move, set stabilizer trim switches to CUTOUT. >If runaway continues, hold the stabilizer trim wheel against rotation and trim the airplane manually. Surely that's not strictly correct? As the switches on the control column have no effect on MCAS "trim", the condition "If relaxing the column causes the trim to move," is never satisfied. So the AD doesn't actually specify "set stabilizer trim switches to CUTOUT" for an unintended MCAS activation. So the second line of the AD should have read something like: >If relaxing the column causes the trim to move - or if this is an inappropriate MCAS activation - set stabilizer trim switches to CUTOUT. Or maybe a negative form would have been better: >If the trim keeps running irrespective of control column input - set stabilizer trim switches to CUTOUT. ... but this would this have handled appropriate MCAS activation? |
The AD procedure was a revision to the runaway trim procedure. The first paragraph just repeats the original trim runaway procedure. The rest of the AD procedure addresses the erroneous AOA scenario. To me, the worst mistake in that AD procedure is the second to last sentence, which, instead of saying "Electric stabilizer trim can be used to neutralize the control column pitch forces" before using the cutout switches, should have said something like "You must use the electric stabilizer trim to neutralize the control column pitch forces before using the CUTOUT switches because the manual trim system will not work if the airplane is significantly out of trim." The Ethiopian crew seemed to figure that out well into the event and switched the electric trim back on, but too late to recover.
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Can I just get confirmation of these points.
Electric trim switches. Electric thumb switches trim wins over MCAS Hidden column-force switches. MCAS wins. Ethiopian captain was trimming 'successfully' - it was on handover to his First Officer that the problem finally got out of hand. Relaxing column forces. The prime problem is the delay before MCAS inputs again. Those five seconds lead to misinterpretation of the trim wheels' renewed cranking. |
If the pilot moves the trim switches on the column, that interrupts/overrides the MCAS commands and the pilots commands are followed by the trim system. MCAS resets and will fire again if more than 5 seconds have passed since the column switches were released and its triggering logic is satisfied.
When MCAS is activated, the column cutout switches are bypassed. This enables MCAS to change the trim in the direction opposite the column input from the pilot based on the presumption that the pilot is approaching a turning stalled condition. |
Originally Posted by Loose rivets
(Post 10566950)
Ethiopian captain was trimming 'successfully' - it was on handover to his First Officer that the problem finally got out of hand.
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Ah, thanks. I had a moment of doubt as I was writing, hence the request for confirmation. If I'd had any idea how many hours I'd be reading in, I'd have taken copious notes with a reference system.
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So, as I understand it to summerise the present situation could be:
1. The EASA will do their own certification (whatever time scale that takes to complete) 2. As of this instant, Boeing is still recruiting for the following positions (temp but full-time): AVIATION MAINTENANCE TECHNICIAN & INSPECTORat Moses Lake to get these aircraft back in the air which means within the next couple of months(?)Which looks to me like the FAA has diverged from the EASA and plans to certify the Max in North America. Nothing else makes sense to me after reading the PowerPoint slides. Boeing and the FAA are in this together and as others have said a lot of jobs and prestige is invested in this model but also the whole Boeing/FAA partnership. Correct me if I have got this wrong by all means. |
Originally Posted by Thistle42
(Post 10567256)
Correct me if I have got this wrong by all means. There is no way in a million years that the MAX will be cleared to fly in North America and still be grounded in the rest of the world. The recruitment of technicians was something Boeing had to do in advance of their stated aim of getting the Max back in the air in September/October. These technicians will most likely be kept on hold until a more realistic date for return to service. |
Sorry, late to the conversation...at this time is there any suggestion we are going to get a third AoA wired up?
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