Ethiopian 737-8 MAX down. No survivors. | Page 17 | FerrariChat

Ethiopian 737-8 MAX down. No survivors.

Discussion in 'Aviation Chat' started by RWatters, Mar 10, 2019.

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  1. boxerman

    boxerman F1 World Champ
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    Yeah and he is following the right strategy legally to limit damage. But from a Boeing brand perspective and therefore long term he is doing the worst possible job.
    Course Boeign also saved a fortune short term by not designing anew plane a decade ago too, and that is costing them now int he race with airbus.

    Maybe he limited liability to 1 billion now instead of 3 billion, and that remeains to be seen. In the longer term lost market share will be way more than 3 billion, thats assuming they can get the maxi pad flying soon, if not 3 billion may seem a small number.

    A 60 odd year premier jet reputation being flushed away, whats the value of that?

    I used to be if its not Boeing I'm not going, now I'm f-em,
     
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  2. F1tommy

    F1tommy F1 World Champ
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  3. Gatorrari

    Gatorrari F1 World Champ
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    Is that one Indonesian airline still the only one who's cancelled their MAX order?
     
  4. F1tommy

    F1tommy F1 World Champ
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    Also Virgin Australia deferred theirs until 2025. Here is all of BFI from the air. 98% of the planes are brand new 737 Max aircraft with a USAF tanker and a few 767-300F's.





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  5. BoulderFCar

    BoulderFCar F1 World Champ
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    Do you have to decommission planes before they sit on the tarmac for months? Is there a process that has to be followed after a long stretch before they fly again?
     
  6. Jeff Kennedy

    Jeff Kennedy F1 Veteran
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    Last I knew they had not cancelled but were putting the order under review. Sounded a lot like a ploy to negotiate a better deal instead of a cancellation.

    The order line at Airbus is quite long so don't be expected many, if any, changes. The additional cost in spare part provisioning throughout an airline's locations, tooling, mechanic training, pilot training and more would be extreme if they already have a fleet of Max.

    The one Airbus in the 320neo family that is really beating the Max in sales is the 321 version that is able to do a lot, but not all, of what the 757 did.
     
  7. Gatorrari

    Gatorrari F1 World Champ
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    If that keeps up they're going to have to keep some in Renton!
     
  8. Jeff Kennedy

    Jeff Kennedy F1 Veteran
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    There are procedures for short term and long term storage. Not sure how much time initiates the need for a storage procedure.
     
  9. Jeff Kennedy

    Jeff Kennedy F1 Veteran
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    Aren't they storing some at Moses Lake already?
     
  10. Tcar

    Tcar F1 Rookie

    Some airlines are... Southwest, I think, for instance.
     
  11. jcurry

    jcurry Two Time F1 World Champ
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    Also a few more tankers on the very south ramp, out of view to top, which is the Boeing Defense ramp.
     
  12. Jeff Kennedy

    Jeff Kennedy F1 Veteran
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    Aviation Week:

    WASHINGTON—The world’s largest pilots’ union will not ask FAA to require additional mandatory simulator training on maneuvering characteristics augmentation system (MCAS) scenarios for 737 MAX pilots before they can fly, but will recommend it as part of routine recurrent training, Aviation Week has learned.

    The Air Line Pilots Association (ALPA) will make its views known in comments on a draft of proposed minimum 737 training standards out for public comment. The Flight Standardization Board (FSB) draft report does not recommend simulator sessions as part of transition training for 737 Next Generation pilots upgrading to the MAX, opting for less costly computer-based training instead.

    A person with knowledge of ALPA’s comments tells Aviation Week that the pilots’ union will go a step further, calling for hands-on simulator training at the earliest scheduled opportunity. Under this scenario, MAX pilots would fly simulated MCAS-related scenarios within a year or so as MAX simulators become available, but not before they return to line operations once flight restrictions on the model are lifted. Some regulators are expected to require simulator training as conditions for removing their operations bans, and Air Canada has said it is already using its MAX simulator—the only one in airline hands in North America—to run its 420 MAX pilots through MCAS-related scenarios.

    ALPA’s training recommendations will include other additions to the draft document as well—most of them emphasizing MCAS-related differences between the NG and the MAX. The MCAS was needed for certification purposes to enhance pitch stability with slats and flaps retracted at very light weights and full aft center-of gravity (CG), ensuring the MAX handled like the NG. The system activates when the aircraft’s speed approaches threshold AOA, or stick-shaker stall-warning activation, for the aircraft’s configuration and flight profile.

    The union wants the AOA Disagree alert message and its relation to MCAS added to items given “special emphasis” in MAX training. The MCAS is fed by angle of attack (AOA) data, and activates when the data shows the aircraft’s nose as being too high for the current flight profile. ALPA wants pilots to understand the link between AOA Disagree alerts, which will now be standard on primary flight displays for all MAXs, and the MCAS’s role of automatically moving the horizontal stabilizer to compensate for an AOA approaching aerodynamic stall.

    The union also wants MAX pilots to understand that nose-down stabilizer trim applied by MCAS cannot be countered by pulling back on the yokes. The MCAS is an extension of the 737 speed trim system (STS), which automatically moves the stabilizer to ensure pitch is maintained as speed increases. On the NG, stick force inputs override runaway trim, including the STS runaways. On the MAX, stick force overrides all runaway trim conditions, but not MCAS.

    Boeing determined that allowing the MCAS to be countered by pulling back on the yoke could negate its purpose, so the column brake is bypassed when the MCAS is activated. Instead, the MCAS can be countered using yoke-mounted electric trim switches or, in extreme conditions, by toggling cutout switches that de-power the trim motors and using hand-cranked trim wheels.

    The public has until May 15 to comment on the draft FSB report. Approving it will be a key step in getting the MAX fleet back in the air, along with having regulators sign off on changes to the MCAS software that Boeing is finalizing.

    FAA said it will consider the public’s input before making a final decision on the FSB’s contents. “We are looking forward to reviewing all of the comments,” the agency said.

    The Air Line Pilots Association did not immediately respond to a request for comment. Regulators grounded the 370-aircraft operational fleet in mid-March following the second of two fatal MAX 8 accidents. The MCAS’s erroneous activation played a role in each accident. Boeing is modifying the system’s logic by adding triple redundant angle of attack validity checks to add data redundancy and reduce its authority to activate multiple times in certain scenarios and by limiting its stabilizer command authority to a single, proportionate nose down trim input.

    Boeing designed the MCAS to operate in the background and only if the aircraft were being operating in a small corner of the flight envelope. Both the company and the original FSB that worked on the model’s 2017 certification determined that special training on the system’s operation was not necessary. As a result, the system was not covered in flight manuals. The updates will add information on the system’s operation.

    Boeing and the 2017 FSB team also determined that pilots would recognize an MCAS-related failure as stabilizer runaway—a common air transport issue that pilots are trained to manage with a memorized checklist.

    But in both MAX 8 accident sequences, the crew did not immediately diagnose the MCAS inputs, trigged by erroneous AOA data, as stabilizer runaway. They countered the MCAS with manual electric trim inputs, which re-set the MCAS and caused it to activate again based on the continued stream of faulty AOA data. Had the crews not used the electric trim, the MCAS system would not have activated repeatedly, eventually leading to uncontrollable dives. Boeing’s software update removes this function so that electric trim does not re-set MCAS so that it cannot operate again based on faulty data.

    ALPA, which represents pilots at MAX operators United Airlines and WestJet, also will advise that pilots practice as many MCAS-failure-related emergency scenarios as necessary to demonstrate competency. Boeing’s explanation of MCAS following the first accident, Lion Air Flight 610 in October 2018, listed nine related “indications and effects” that could result from an AOA Disagree alert and possible MCAS activation.

    While the FSB still must be finalized, mandatory simulator training before qualified 737NG pilots fly the MAX is not expected to be part of the package.

    “At this point, we’re not hearing that [simulator training] will be a requirement,” Southwest Airlines CEO Gary Kelly said recently. “Just getting pilots back into the simulator for an event would be a challenge, and that would take time. But my own interpretation is that we already do the kind of training that one would be contemplating to put the MAX back into service. Managing the aircraft in a runaway stabilizer scenario is something that we already trained on and…has already been covered.”
     
  13. F1tommy

    F1tommy F1 World Champ
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    So this is being blamed mostly on the pilots. I read the EU and China are putting a lot of political pressure that could play a part in future certifications as a result of these 2 accidents.

    "In both MAX 8 accident sequences, the crew did not immediately diagnose the MCAS inputs, trigged by erroneous AOA data, as stabilizer runaway. They countered the MCAS with manual electric trim inputs, which re-set the MCAS and caused it to activate again based on the continued stream of faulty AOA data. Had the crews not used the electric trim, the MCAS system would not have activated repeatedly, eventually leading to uncontrollable dives. Boeing’s software update removes this function so that electric trim does not re-set MCAS so that it cannot operate again based on faulty data. "
     
  14. Jeff Kennedy

    Jeff Kennedy F1 Veteran
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    I would not put it past EASA to try for some "superiority" attempts so they can show that they are not a step child to the FAA.

    As for the pilots, the flight before on Lion Air proved that an alert pilot that could recognize the runaway trim situation could avoid the crash. Ethiopia pilots didn't recognize it soon enough and then let too many factors get into an unrecoverable situation.

    What does surprise me is that there is not going to be a simulator requirement so that pilots get training in how to recognize the situation at/near the onset. This would be especially important when there is more than one failure going on at the same time. If the FAA and others don't require this hopefully some of the airlines will at least make it part of their procedures.
     
  15. BubblesQuah

    BubblesQuah F1 World Champ
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    Is erroneous AOA data a common thing?
     
  16. F1tommy

    F1tommy F1 World Champ
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    Somewhat rare, but the sensor coming completely detached is really rare as it looks like it did on the Ethiopia crash. In fact I know of only one time I have heard of it happening when I was working, and that was also caused by a bird strike.
     
  17. BubblesQuah

    BubblesQuah F1 World Champ
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    Was just thinking that if bad AOA data happened on 2 different, relatively uncommon aircraft, within months of each other - how many times did it happen on more common aircraft like every other 737, or 777's, or anything else in that same time period?
     
  18. jcurry

    jcurry Two Time F1 World Champ
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    Things malfunction/break on airplanes everyday, they just don't make the news because critical items generally have built-in redundancy or working annunciators to warn pilots of the issue.
     
  19. BubblesQuah

    BubblesQuah F1 World Champ
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    Yes, I understand that.

    Are you saying that AOA sensors typically fail at the same rate on all aircraft? I'm not sure what the acceptable measurement is, but let's say per flight hour. If so, it seems like there would have been hundreds of AOA failures on other aircraft during the same time period that the MAX has it's 2. And maybe there was - that's really what I was wondering about...
     
  20. jcurry

    jcurry Two Time F1 World Champ
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    https://www.heraldnet.com/nation-world/not-just-the-737-angle-of-attack-sensors-have-had-problems/
    Doubtful that the FAA database contains every occurrence.
     
  21. Boomhauer

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  22. tazandjan

    tazandjan Three Time F1 World Champ
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    Rogue, typical of today's mass media.
     
  23. Fave

    Fave F1 Rookie

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    Watched that then the 2014 Al Jazeera investigation docu on the 787. Swap the AOA sensor for the LiPo batteries and the story is the same. I'm now surprised something like this hasn't happened sooner. Boeing better get their s**t together.

    The Boeing 787 Broken Dreams:
     
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  24. Jeff Kennedy

    Jeff Kennedy F1 Veteran
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    Ethiopian MAX Crash Simulator Scenario Stuns Pilots
    May 10, 2019 Sean Broderick | Aviation Daily

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    Wreckage from Ethiopian Airlines Flight 302.

    Jemal Countess/Getty Images

    WASHINGTON—A simulator session flown by a U.S.-based Boeing 737 MAX crew that mimicked a key portion of the Ethiopian Airlines Flight 302 (ET302) accident sequence suggests that the Ethiopian crew faced a near-impossible task of getting their 737 MAX 8 back under control, and underscores the importance of pilots understanding severe runaway trim recovery procedures.

    Details of the session, shared with Aviation Week, were flown voluntarily as part of routine, recurrent training. Its purpose: practice recovering from a scenario in which the aircraft was out of trim and wanting to descend while flying at a high rate of speed. This is what the ET302 crew faced when it toggled cutout switches to de-power the MAX’s automatic stabilizer trim motor, disabling the maneuvering characteristics augmentation system (MCAS) that was erroneously trimming the horizontal stabilizer nose-down.

    In such a scenario, once the trim motor is de-powered, the pilots must use the hand-operated manual trim wheels to adjust the stabilizers. But they also must to keep the aircraft from descending by pulling back on the control columns to deflect the elevator portions of the stabilizer upward. Aerodynamic forces from the nose-up elevator deflection make the entire stabilizer more difficult to move, and higher airspeed exacerbates the issue.

    The U.S. crew tested this by setting up a 737-Next Generation simulator at 10,000 ft., 250 kt. and 2 deg. nose up stabilizer trim. This is slightly higher altitude but otherwise similar to what the ET302 crew faced as it de-powered the trim motors 3 min. into the 6 min. flight, and about 1 min. after the first uncommanded MCAS input. Leading up to the scenario, the Ethiopian crew used column-mounted manual electric trim to counter some of the MCAS inputs, but did not get the aircraft back to level trim, as the 737 manual instructs before de-powering the stabilizer trim motor. The crew also did not reduce their unusually high speed.

    What the U.S. crew found was eye-opening. Keeping the aircraft level required significant aft-column pressure by the captain, and aerodynamic forces prevented the first officer from moving the trim wheel a full turn. They resorted to a little-known procedure to regain control.

    The crew repeatedly executed a three-step process known as the roller coaster. First, let the aircraft’s nose drop, removing elevator nose-down force. Second, crank the trim wheel, inputting nose-up stabilizer, as the aircraft descends. Third, pull back on the yokes to raise the nose and slow the descent. The excessive descent rates during the first two steps meant the crew got as low as 2,000 ft. during the recovery.

    The Ethiopian Ministry of Transport preliminary report on the Mar. 10 ET302 accident suggests the crew attempted to use manual trim after de-powering the stabilizer motors, but determined it “was not working,” the report said. A constant trust setting at 94% N1 meant ET302’s airspeed increased to the 737 MAX’s maximum (Vmo), 340 kt., soon after the stabilizer trim motors were cut off, and did not drop below that level for the remainder of the flight. The pilots, struggling to keep the aircraft from descending, also maintained steady to strong aft control-column inputs from the time MCAS first fired through the end of the flight.

    The U.S. crew’s session and a video posted recently by YouTube’s Mentour Pilot that shows a similar scenario inside a simulator suggest that the resulting forces on ET302’s stabilizer would have made it nearly impossible to move by hand.

    Neither the current 737 flight manual nor any MCAS-related guidance issued by Boeing in the wake of the October 2018 crash of Lion Air Flight 610 (JT610), when MCAS first came to light for most pilots, discuss the roller-coaster procedure for recovering from severe out-of-trim conditions. The 737 manual explains that “effort required to manually rotate the stabilizer trim wheels may be higher under certain flight conditions,” but does not provide details.

    The pilot who shared the scenario said he learned the roller coaster procedure from excerpts of a 737-200 manual posted in an online pilot forum in the wake of the MAX accidents. It is not taught at his airline.

    Boeing’s assumption was that erroneous stabilizer nose-down inputs by MCAS, such as those experienced by both the JT610 and ET302 crews, would be diagnosed as runaway stabilizer. The checklist to counter runaway stabilizer includes using the cutout switches to de-power the stabilizer trim motor. The ET302 crew followed this, but not until the aircraft was severely out of trim following the MCAS inputs triggered by faulty angle-of-attack (AOA) data that told the system the aircraft’s nose was too high.

    Unable to move the stabilizer manually, the ET302 crew moved the cutout switches to power the stabilizer trim motors—something the runaway stabilizer checklist states should not be done. While this enabled their column-mounted electric trim input switches, it also re-activated MCAS, which again received the faulty AOA data and trimmed the stabilizer nose down, leading to a fatal dive.

    The simulator session underscored the importance of reacting quickly to uncommanded stabilizer movements and avoiding a severe out-of-trim condition, one of the pilots involved said. “I don’t think the situation would be survivable at 350 kt. and below 5,000 ft,” this pilot noted.

    The ET302 crew climbed through 5,000 ft. shortly after de-powering the trim motors, and got to about 8,000 ft.—the same amount of altitude the U.S. crew used up during the roller-coaster maneuvers—before the final dive. A second pilot not involved in the session but who reviewed the scenario’s details said it highlighted several training opportunities.

    “This is the sort of simulator experience airline crews need to gain an understanding of how runaway trim can make the aircraft very difficult to control, and how important it is to rehearse use of manual trim inputs,” this pilot said.

    While Boeing’s runaway stabilizer checklist does not specify it, the second pilot recommended a maximum thrust of 75% N1 and a 4 deg. nose-up pitch to keep airspeed under control.

    Boeing is developing modifications to MCAS, as well as additional training. Simulator sessions are expected to be integrated into recurrent training, and may be required by some regulators, and opted for by some airlines, before pilots are cleared to fly MAXs again. The MAX fleet has been grounded since mid-March, a direct result of the two accidents.
     
  25. jcurry

    jcurry Two Time F1 World Champ
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    Used to have to perform a similar maneuver on my old Mooney with the Johnson Bar gear. If you got too fast in climb out the aero loads on the gear doors would create excessive loads when trying to retract the gear. A slight push-over would relieve the load and allow the gear to be retracted easily. Kudos to the US based crew in the simulator for thinking of that, i.e. unloading the tail, but it seems obvious that in the actual crash flight at much lower altitude it would not have prevented the crash.
     

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