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  1. #201
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    Quote Originally Posted by Ziggy2 View Post
    This is pure speculation but it seems to me that the flight path characteristics are similar in nature to the problems an airframe has when the C.G. is moving in flight or a C.G. to far astern.

    A lot of times pilot error always goes to the top of the list, then mechanical failure or mechanical problems but the actions of the ground crew or just human ignorance can create situations that even the most skilled pilot or the best engineered system can not cope with.
    Seems to me it wouldn’t be that hard to instrument the landing gear for weight distribution.

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    Quote Originally Posted by jancollc View Post
    That's what got my attention too. They basically rotated right into a stall at about 300 feet above the ground, and just barely recovered from that.

    Was the plane even correctly configured for takeoff?
    This is my thought

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    Quote Originally Posted by EmanuelGoldstein View Post
    You think it was loaded with Ukrainian mail order brides and they all ran to the back to wave bye-bye ?

    A long time ago they ran semi-cargo 747's to China - the back third was cargo and there was a door. Usually locked.

    But one flight I saw this guy who kept going through the door, then coming back out. He was checking on the horses Seriously, they had about ten horses on the plane. Could have got ugly if they freaked out and started kicking ...
    I could see if someone brought a bunch of dogs yet horses are mush bigger they could totally lose composure once they realize they are on a Jet plane with two pilots flying to China.
    I bet once they might learn that or just be frightened by the confined space, the noise , and the strange movements then they could start bucking. That is a scary scenario.

    Oh well at least there is lots of Horse tranquilizers.

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    The global news reported satellite data showing erratic up/down movements on both aircraft.
    Perhaps the same, similar, for a similar reason.

    Similar reports from pilots in the recent past in a us database for issues.

    Where the potential for harm is great, much prudence is indicated.

    In this case for boeing, I see a coverup, of an innocent mistake.
    US multinationals are notorious for these, in all fields.
    And little real liability.

    Obviously Boeing can and will fix the issue if it is in the sw.
    A quick-fix might take only weeks.

    The base problem is US tort law and stock market driven decisions, where the issues are secondary to the financials and perceived news.

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    Quote Originally Posted by Spinit View Post
    I could see if someone brought a bunch of dogs yet horses are mush bigger they could totally lose composure once they realize they are on a Jet plane with two pilots flying to China.
    I bet once they might learn that or just be frightened by the confined space, the noise , and the strange movements then they could start bucking. That is a scary scenario.

    Oh well at least there is lots of Horse tranquilizers.
    They fly them in creates not disimalr to horse boxes. Really common in the race horse industry lots get flown into and out of the uk all the time. had a girlfriend that use to be involved in the horse racing industry and whilst she just delt with stabling them and training them here in the uk, they very much spend a lot of there lives in transit between different venues by all means of transit. Supposedly once they get use to it its kinda like us humans it just becomes another day at the office and whilst they can sedate them they really try not too as it makes them more inclined to fall over and supposedly that's the biggest issue with horses in transit.

    They did "blinker?" them so they could not see too much and they also had horse ear muffs for them, (assumed the horse ear muffs was a wind up too till i was shown them) So they did not get too easily startled.

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    I looked at the altitude and speed charts in Adama's video, and if accurate, tell this story:

    1. Normal takeoff, but degraded rate of climb due to altitude, heat, etc. See the comparable plots form other takeoffs that day.
    2. Something bad happens @ ~100 seconds into the flight, ~500' AGL and ~250 kts
    3. Airplane drops rapidly, recovers, then climbs steeply.

    The chart data ends there.

    The most significant data, IMO, is the abundance of airspeed -- steady rise through 300 kts. Not what you would see in a stall or impending stall condition.

    Regards.

    Mike

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    [QUOTE=hanermo;3329715]The global news reported satellite data showing erratic up/down movements on both aircraft.
    Perhaps the same, similar, for a similar reason.

    Similar reports from pilots in the recent past in a us database for issues.

    Where the potential for harm is great, much prudence is indicated.

    quoteIn this case for boeing, I see a coverup, of an innocent mistake.
    US multinationals are notorious for these, in all fields./quote
    And little real liability.

    Obviously Boeing can and will fix the issue if it is in the sw.
    A quick-fix might take only weeks.

    The base problem is US tort law and stock market driven decisions, where the issues are secondary to the financials and perceived news.
    I do not believe Boeing is covering up really. I know it is easy to be suspicious. Boeing is a very large and successful company and to get that way they make good/superior (other opinions noted) product.

    Not sure how US tort law would be a problem here. Every country has their tort law. For the victims agreement is I heard yet have no cite that the victims have a agreed upon cap for payment to families. That way there is not a bunch of lawsuits when this happens.

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    Quote Originally Posted by Finegrain View Post
    ...The most significant data, IMO, is the abundance of airspeed -- steady rise through 300 kts. Not what you would see in a stall or impending stall condition.
    There are 2 charts for speed and time, the one with more detail shows a drop at 6 seconds, then another at about 55 seconds. We don't know the sampling interval on the second chart, and it says "speed does not start at zero", even though the chart starts at zero.

    We have no information on airspeed. Both charts are speed over ground. You can have a high ground speed and still be in a stall condition. Both charts appear to show a decrease in ground speed at the same spot just before the drop in altitude.

    The data is not enough to draw a conclusion, but if we trust the video (I don't) it's definitely not a normal takeoff. In those conditions- hot, humid, high altitude- the wings are not generating lift and the engines are not generating power like a sea level takeoff. You need to allow for it, you can find yourself unable climb out of ground effect.

    Density altitude has killed a lot of pilots.

    The FDR will tell what really happened.

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    Why would the MCAS system be active during takeoff?

    Is the airplane not under full power at takeoff? Thus, a stall should be a very unlikely occurrence?

    Is the MCAS just an anti-stall system, or is it required at all times to make the plane flyable??

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    Quote Originally Posted by cnctoolcat View Post
    Why would the MCAS system be active during takeoff?

    Is the airplane not under full power at takeoff? Thus, a stall should be a very unlikely occurrence?

    Is the MCAS just an anti-stall system, or is it required at all times to make the plane flyable??
    There have been accidents caused by incorrect flap/slat configuration on take off, causing a stall condition.

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    Quote Originally Posted by cnctoolcat View Post
    Why would the MCAS system be active during takeoff?

    Is the airplane not under full power at takeoff? Thus, a stall should be a very unlikely occurrence?

    Is the MCAS just an anti-stall system, or is it required at all times to make the plane flyable??
    MCAS is designed to be active anytime the autopilot is not engaged. It is meant to assist in manual flight.

    Takeoff is indeed to most important time to have something like MCAS, as stalling the A/C is entirely possible right after takeoff, if you are fighting for altitude.

    Yes, the A/C is under full power at takeoff, but right after takeoff, the A/C is near stall speed, and until you gain some airspeed, stalling is a possibility.

    Back in the day, flying in old, smoky, not-high-bypass turbojet 4-engine USAF A/C, you had to gain some airspeed before you could maneuver. Completely unlike today's passenger jets that have way more thrust/weight and can make pretty impressive rates of climb even immediately after liftoff.

    Regards.

    Mike

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    Quote Originally Posted by hanermo View Post
    Obviously Boeing can and will fix the issue if it is in the sw.
    A quick-fix might take only weeks.
    If you've ever worked in OEM aerospace, you'll know that this is the understatement of the century.
    Level 1 software nowadays is entombed in hours and hours and hours of structured testing.

    I just emailed a mate who was in Germany last week for the avionics show to see if he knew anything. This is his reply:-

    Well...... according to the boys I spoke to in Munich, Boeing are making a change to the control law pitch authority, which is a configurable parameter, so not a software change as such, but 1000s of hours of testing and documentation.
    They have been working on it since the Loin Air crash last year.

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    Quote Originally Posted by barbter View Post
    If you've ever worked in OEM aerospace, you'll know that this is the understatement of the century.
    Level 1 software nowadays is entombed in hours and hours and hours of structured testing.

    I just emailed a mate who was in Germany last week for the avionics show to see if he knew anything. This is his reply:-

    Well...... according to the boys I spoke to in Munich, Boeing are making a change to the control law pitch authority, which is a configurable parameter, so not a software change as such, but 1000s of hours of testing and documentation.
    They have been working on it since the Loin Air crash last year.
    Yep...
    Thinking there’s a “quick fix” through software is my pet peeve as a machine designer.
    Layering quick fix on quick fix to patch something is just plain BS.

    I have to wonder if the stall system might fall under that mindset.

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    Quote Originally Posted by Finegrain View Post
    MCAS is designed to be active anytime the autopilot is not engaged. It is meant to assist in manual flight.

    Takeoff is indeed to most important time to have something like MCAS, as stalling the A/C is entirely possible right after takeoff, if you are fighting for altitude.

    Yes, the A/C is under full power at takeoff, but right after takeoff, the A/C is near stall speed, and until you gain some airspeed, stalling is a possibility.
    There are 3 conditions that have to be met for MCAS to intervene.

    Autopilot OFF
    Flaps UP
    AOA HIGH

    MCAS (Maneuvering Characteristics Augmentation System) is implemented on the 737 MAX to enhance pitch characteristics with flaps UP and at elevated angles of attack. The MCAS function commands nose down stabilizer to enhance pitch characteristics during steep turns with elevated load factors and during flaps up flight at airspeeds approaching stall. MCAS is activated without pilot input and only operates in manual, flaps up flight.
    MCAS does not operate in takeoff configuration since flaps are extended.

    I looked at the takeoff from Flight Radar (the source of the first graph in that video), it shows the nose off the runway at 93KTS. That's a long way from normal takeoff speed which should have been closer to 140-160 KIAS. For some reason I can't attach the image. It shows a rate of climb of 128ft/min for 9 seconds, decreases to 64ft/min, then zero for 10 seconds. The plane continued to accelerate to 174KTS before resuming a slow climb. From there on it went up and down at varying rates, the data cuts off at 3 minutes.

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    Thanks for clarifying J!

    Do you have links to the radar showing rotate at 93? That would be very low for a 737.

    Regards.

    Mike

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    Quote Originally Posted by barbter View Post
    ...Boeing are making a change to the control law pitch authority, which is a configurable parameter, so not a software change as such, but 1000s of hours of testing and documentation.
    They have been working on it since the Loin Air crash last year.
    That's correct. The FAA issued an Emergency AD on Boeing last November to correct the MCAS behavior in the case of a faulty AOA sensor- the reported cause of the Lion Air crash.

    It has to go through testing and certification. The schedule has always been end of March for delivery.

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    Quote Originally Posted by Finegrain View Post
    Thanks for clarifying J!

    Do you have links to the radar showing rotate at 93? That would be very low for a 737.
    I got it from their twitter feed, I don't think I can find it again. I saved it to my computer, but when try to attach the file all I get is a blank attachments box.

    If you PM me your email, I will email it and you can post it here.

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    I'm not sure that a 737 could rotate at 93 knots at 7300 feet above sea level.

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    Quote Originally Posted by Mark Rand View Post
    I'm not sure that a 737 could rotate at 93 knots at 7300 feet above sea level.
    Apparently it can, but only for a very short time

    So now Boeing is engaged in a massive coverup, in case other idiots try this same trick ....

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    Quote Originally Posted by jancollc View Post
    I looked at the takeoff from Flight Radar (the source of the first graph in that video), it shows the nose off the runway at 93KTS. That's a long way from normal takeoff speed which should have been closer to 140-160 KIAS. For some reason I can't attach the image. It shows a rate of climb of 128ft/min for 9 seconds, decreases to 64ft/min, then zero for 10 seconds. The plane continued to accelerate to 174KTS before resuming a slow climb. From there on it went up and down at varying rates, the data cuts off at 3 minutes.
    Weight and balance problem? Load shift?

    I read the flap limit speed for flaps 1 & 5 is 250 knots so they might have still had T/O flaps so that would rule out MCAS...


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