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Old 5th Aug 2011, 14:13
  #1600 (permalink)  
takata
 
Join Date: Jun 2009
Location: Paris
Posts: 691
Originally Posted by airtren
A red vertical line is the moment of the Normal to Alternate Law change.
I notice a Pitch Nose Down, right before the Law change.
I can also see now, that the slight Altitude loss was right after the Law change.
Removing, at this point, the "turbulence" effect (the good clue to see its effect is to look at simulated longitudinal axis analysis tables provided), nonetheless you are right about the up/down caused.

Anyway, change of law is due to unreliable airspeed.
The pitch down (at longer term) moment is also due to the reduction of thrust at 0209:58 (Mach 0.80 selected), decrease is about 15% in few seconds.
Altitude is "indicated altitude", as well as speeds, and UAS is causing a loss of "indicated" altitude (but ISIS is barely not affected, about 100 ft). It is obvious when you compare pitch vs V/S curves and altitude altogether: the former increased but altitude indicated change is delayed by 10-15 seconds.
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