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Old 4th Aug 2010, 23:14
  #344 (permalink)  
PJ2
 
Join Date: Mar 2003
Location: BC
Age: 76
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p51guy;
GPWS was max power 20 degrees nose up so that sounds like a lot closer to best angle than best rate for obvious reasons. Clearing close in terrain is the object, not reaching altitude quickly.
I'm just thinking this through a bit. Since Max "Rate of Climb" is maximum altitude over time and "Max Angle of Climb" is max altitude over distance and since EGPWS works on a specified time (60" and 30" approx), and therefore varies distance according to speed, it is reasonable to conclude that the priority is Rate of Climb, but I gotta say that in Alpha Floor, the actual speed is just above the stall (at AlphaMax) so perhaps the designers chose an immediate pitch-up & power response and never considered either rate or angle of climb, neither of which would likely be the actual speed flown when executing the maneuver!

The other thing to consider of course, now that we're on this tack and which renders moot any discussion of rates and angles of climb, is, 99% of the time, the aircraft is a long, to a very long way from Alpha Floor. So the response to any full back-stick (or 20deg pitch-up) and TOGA thrust application will be very brisk indeed....6000 to 8000 fpm for a brief period, trading energy for altitude, would not be unrealistic.

PJ2

Last edited by PJ2; 5th Aug 2010 at 06:27. Reason: add comment re 20deg pitch-up response
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