PPRuNe Forums - View Single Post - A320 CG correction when to apply?
View Single Post
Old 30th Sep 2016, 20:34
  #7 (permalink)  
FlightDetent

Only half a speed-brake
 
Join Date: Apr 2003
Location: Commuting not home
Age: 46
Posts: 4,319
Received 3 Likes on 3 Posts
Denti, depends on how your iPad (or whatever app you're using) is configured. The label is modifiable by the administrator, ours currently reads <= 27%.

Answer: according to Airbus guidance, the limit when to apply alternative forward CG lo-speed performance corrections is 27% indicated CG. (reference available).

The logic is, as I understand it: The aircraft is flown-certified with 25% CG position as the differentiating value. In controlled condtions, loading-wise, that is.

Because in real life operating scenario, the calculated / indicated CG postion is only approximation of actual CG - true passanger weight distribution being the most variable factor - a conservative margin of 2% is normally added to the limiting value.

It is easy to understand that RTOW charts show 25% because that's how they are calculated, but to use them without a correction for forward CG, one needs LDS figure of 27 or more.
FlightDetent is offline