Page 1 of 1

Centre of gravity?

PostPosted: Thu Feb 07, 2008 1:33 pm
by gypsymoth
When looking at Fuel & Payload, does the CoG envelope begin & end at the red lines at the wing edges?    I have something with its CoG at the cockpit level.   :o

Re: Centre of gravity?

PostPosted: Thu Feb 07, 2008 4:28 pm
by garymbuska
[quote]When looking at Fuel & Payload, does the CoG envelope begin & end at the red lines at the wing edges?

Re: Centre of gravity?

PostPosted: Fri Feb 08, 2008 5:48 pm
by gypsymoth
Hi gary - I just want to know if the envelope is between the red lines front & back of the wing area?  Where does the CofG envelope begin & end?   :-?i

Re: Centre of gravity?

PostPosted: Fri Feb 08, 2008 6:12 pm
by microlight
gypsymoth,

Yes, the CG envelope lies between the forward and rear red lines (at the forward and rear wing edges). A FD designer will normally aim to get the CG within this range so that the aircraft balances properly with the minimum of trim necessary. If your CG is too far forward (beyond the forward edge of the envelope) then when autopilot is switched in, you will notice that the elevator trim settings are higher than they would be otherwise. Someone here described the flight characteristics as being like a shuttlecock, which was a good way of looking at it.

Another way to confirm that the CG is not right is to see what happens when you intercept the glideslope. A well-balanced plane will nose-down gently so that there is a smooth transition, but a nose heavy plane will dip its nose (alarmingly, sometimes). So control on approach is difficult, not to mention flare.

;)

Re: Centre of gravity?

PostPosted: Fri Feb 08, 2008 9:21 pm
by garymbuska
Sorry about that I miss under stood you.
But Gypsymith is correct. If you suspect that you have a aircraft with a COG problem one way to spot it is after you have selected the aircraft open up the change fuel payload menu then remove all of the fuel and all of the weight this will give you a good idea as to how well balanced it is empty.I have downloaded so many aircraft that are either very tail heavy or very nose heavy.  8-)