Empty CG Position

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Community-driven support for Project Airbus aircraft only.
Community-driven support for Project Airbus aircraft only.
Community-driven support for Project Airbus aircraft only.
Community-driven support for Project Airbus aircraft only.
Community-driven support for Project Airbus aircraft only.
Community-driven support for Project Airbus aircraft only.

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atav
Posts: 2
Joined: 17 Oct 2012, 19:24

Empty CG Position

Post by atav »

Hello folks!

I'm trying to make my weight and balance preparation of my Airbuses as accurate as possible using W&B manuals of airlines. Here's the thing: So after some calculations, I've come up with a certain A321's empty weight MAC to be at 18%. With some math that puts the CG at about 47 feet forward of the exact centre of the A321 (146 feet long divided by two minus 26 feet from nose etc.) In the aircraft cfg for the A321 the reference datum is at 0,0,0 (exact centre I assume?) So when I put in the empty_weight_GG_position as 47, it seems to be way off, at least when I try to fly and can't leave a nose-dive. So is there a correct way to make the empty CG position in the aircraft cfg at 18% or 47 feet ahead of the centre?? Thanks

-Alex

Derek Mayer
Posts: 236
Joined: 02 Jul 2009, 16:13

Re: Empty CG Position

Post by Derek Mayer »

Are you sure you've calculated that right? 47 feet forward of center is way out there, I highly doubt that's the correct value. I've measured 18% MAC on our A321 model and it turns out to be about -3 feet (3 feet behind) our reference datum.

atav
Posts: 2
Joined: 17 Oct 2012, 19:24

Re: Empty CG Position

Post by atav »

Well yes, using company data I chose a random A321 which had a dry operating index of 36.03, which at 48.8 tonnes put me at 18%,which I agree seems very forward. But that's what It came out to! How can I figure out where for example PA puts their reference data for the A319/20/21s in the future? Or will I just have to ask? :P

Thanks by the way very much!

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