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jordanal

MD-11: Approach Flaps Methodology & G/S bug?

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Hey all,Fully enjoying the MD-11 and I completed my first trans-atlantic flight yesterday as well. My observation over the past several flights using a full Profile-descent directly to a coupled ILS autoland is that once I'm at or below the 240kt initial approach speed, the FMS assigned speeds don't seem to change unless I drop the slats and flaps first, then the speed-bug reacts appropriatly. Where as on the Boeings, it always seemed like the speed-bug would drop ahead of time and I as the pilot would apply the appropriate flaps on schedule.So, is this a normal difference between the MD and the Boeings where it seems the current MD approach flaps drive the current FMS speed? Or, I am doing something inappropriate?Also, the other thing I noticed yesterday was that when I was well above the FAF for the chosen ILS, the G/S still coupled at the same time as the LOC and it started a forcefull descent (~ 4Kft/min), quite drasticaly, down to put the G/S center-scale. My point here is, I was always under the impression that if you came in high on the ILS, the G/S would not couple because of the unsafe nature of a drastic descent at such a low altitude. Is this a possible bug or does the real MD-11 allow above G/S captures?Regards,


Regards,
Al Jordan | KCAE

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Regarding automatic deceleration :http://ops.precisionmanuals.com/wiki/PMDG_...during_approachThe quoted distances are ofcourse the sane latest moment at which you extend slats/flaps.PROF will not reduce speed until the point calculated where decel to next target is required or slats/flaps are extended.Boeings do NOT do automatic deceleration. You see the speed bug dropping because you defined (manually) a speed srestriction somewhere and VNAV allows lower and lower targets (until equal to the entered speed restriction) as flaps are extended.Regarding GS capture : this is a plane feature.===================================== E M V Precision Manuals Development Group www.precisionmanuals.com=====================================


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E M V

Precision Manuals Development Group

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Guest Totalbeginner

>Also, the other thing I noticed yesterday was that when I was>well above the FAF for the chosen ILS, the G/S still coupled>at the same time as the LOC and it started a forcefull descent>(~ 4Kft/min), quite drasticaly, down to put the G/S>center-scale. My point here is, I was always under the>impression that if you came in high on the ILS, the G/S would>not couple because of the unsafe nature of a drastic descent>at such a low altitude. Is this a possible bug or does the>real MD-11 allow above G/S captures?>>Regards,The same thing happens in the 744 and it's a real pain. It makes it impossible to do a constand descent approach because as soon as the LOC is captured, the aircraft dives like a suicidal maniac!Martin

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> Dives like a suicidal maniac!Which is why it is usual on most ILS Charts for the aircraft to approach below the G/S and pick it up by flying into it.It's a rare occasion that ATC will vector you to an ILS from above the glideslope. On the few occasions that it has happened to me, it's generally only been a hundred feet above, usually less, but i agree, it doesn't half go for it when you are high! ;)CheersPaul

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