PPRuNe Forums - View Single Post - A320 CDFA LNAV NAV/FPA
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Old 25th Feb 2019, 02:07
  #11 (permalink)  
FlightDetent

Only half a speed-brake
 
Join Date: Apr 2003
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Originally Posted by sonicbum
You're ready to "pull" by the .3 NM.
The advance pull is required to exit ALT mode to FPA or V/S timely enough so that through inertia and automation lag the aircraft wouldn't start descending late - the actual trajectory.


Because in Miguel's scenario he's already in an active vertical mode, the advice above does not apply.
You can change the reference to FPA any time, even at 10000 or higher. My personal technique for the profile they demand is in the previous message. What is also perfectly doable, is to keep V/S even a little longer, past the FAF. No benefit at all in doing so but no harm done either.

@migueloliv:
As long as you know which trajectory you want and where the aircraft is, you will be fine. Take any reference you need to keep the task as easy as possible - that is correct use of automation and cockpit resources (evaluation item). Inevitably, at one point you want FPA instead of V/S.


The guidance to do 1 / 0.3 NM, from your type rating course
- assumes you are closing to FAF in ALT mode
- has a technical reasons behind each of the values.
Neither of which applies for your question.



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