Boeing Targets December For New MAX Deliveries

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Boeing believes it could resume deliveries of its grounded 737 MAX model as early as December, according to a progress report released by the company on Monday. The report also outlined five key milestones the company needs to reach with the FAA before the aircraft returns to service in the U.S. The first, an FAA eCab simulator certification session, was completed last week. Boeing emphasized that it is still targeting the final quarter of 2019 for certification of the aircraft’s updated flight control software.

“Based on this schedule, it is possible that the resumption of MAX deliveries to airline customers could begin in December, after certification, when the FAA issues an Airworthiness Directive rescinding the grounding order,” Boeing said. “In parallel, we are working towards final validation of the updated training requirements, which must occur before the MAX returns to commercial service, and which we now expect to begin in January.”

The milestones still to be accomplished include a “multi-day simulator session with airline pilots to assess human factors and crew workload,” an FAA certification flight test, submission of the “final certification deliverables and artifacts” to the FAA and a simulator training evaluation by the Joint Operational Evaluation Board (JOEB). Last week, both Southwest and American Airlines pushed the expected return to service dates for their MAXs to March 2020. The MAX was grounded in March 2019 after the fatal crashes of Lion Air Flight 610 and Ethiopian Airlines Flight 302.

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9 COMMENTS

  1. Copied from above: “The milestones still to be accomplished include a “multi-day simulator session with airline pilots to assess human factors and crew workload,”
    A multi day sim session???
    I guess that is make sure pilots know how to cut off the stab trim???
    Would like to hear response from others.

    • One of the many items on the original list is how much authority to grant MCAS. It started out as a specialty trim system, to keep handling characteristics similar to old 73’s, but ended up with enough authority to crash two airplanes, as it didn’t recognize the faulty input from a failed sensor.
      The details aren’t available, but I’m going to guess that full MCAS trim can be outflanked by yoke displacement.

      • The MCAS had NO “authority to crash two airplanes.” The pilots did that.
        MCAS had authority to command full nose-down trim, which in the hands of four mortal pilots, proved to be too much for them to deal with.

        Trim on a 737 moves the entire horizontal stabilizer; the yoke moves the elevator. Full deflection of the elevator is insufficient to overcome the effect of full trim.

  2. Because of high fuel expense, airlines demand airplane manufacturers like Boeing utilize the most efficient engines as they become available for a new airplane. The original 737 sits low to the ground and would not allow retrofit of the new larger diameter, more efficient engines in their “normal” location.

    Instead of going to the expense of designing an entirely new clean sheet airplane with adequate ground clearance to properly utilize these larger engines; Boeing chose relocate the 737 MAX engines further forward on extended pylons and raised slightly for sufficient ground clearance.
    The problem is that the engines in their new more forward location tend to cause a pitch up force, especially at full power as during takeoff.

    Because of this pitch up force, it was deemed necessary to provide an automatic feature that would counter an excessive climb attitude if pilots somehow became unaware, hence the installation of the Maneuvering Characteristics Augmentation System (MCAS) that could, in some instances, override pilot control of stabilizer trim; sometimes creating such pitch control downforce that pilots were unable to wrestle control away from this automatic feature; especially once the airplane was in a dive. Even if the MCAS system was manually disconnected by the pilot, under certain conditions, it would automatically reset.

    I am not even going to speak to the problem of lack of training or the failure of Boeing to provide adequate information about the new MCAS system to 737 MAX pilots.

    A mechanical angle of attack sensor, such as used on Boeing’s MCAS system is mounted on the side of the fuselage, is subject to all kinds of hazards including ice, water intrusion, bird strikes, etc. and in one case, at least, someone hanging a bag on the moveable mechanical blade type sensor. Such abuse can easily cause sensor damage or binding, resulting in erroneous information provided to the autopilot.

    So far, not great; but Boeing chose depend on ONE mechanical blade type sensor to provide this critical attitude information to the MCAS system, without any REDUNDANCY.
    Aircraft engineers and are definitely NOT stupid people. I, for one, cannot believe that at least one engineer at Boeing did not bring this lack of redundancy of a critical mechanical sensor to management’s attention.

    As for the new 737 MAX with autopilot now receiving attitude information from TWO MCAS sensors and with new software that will not allow the MCAS system to operate if a significant signal difference between the sensors is detected, I am sure the that new 737 MAX will serve the airlines and their passengers quite well, after a brief period of confidence regaining.

  3. It is incorrect to say “in some instances, override pilot control of stabilizer trim.” The pilots manual electric trim has priority over speed trim and MCAS trim.
    In fact the crews of both flights could have overridden the MCAS trim using Manuel electric trim inputs.

    All aircraft with engines slung under the wing have a substantial pitching moment when thrust is increased. The MAX is far from unique in that respect, but apparently it has some additional.