Anyone know why the ZFWCG is out of range when the aircraft (all versions) has no payload or passengers? How do pilots fly the aircraft when it's empty? This is according to the MD-11 load manager.

ZFWCG is out of range when the aircraft (all versions) has no payload or passengers?

 

The MD-11 has an aft center of gravity. The more forward the center of gravity is, the more stable the aircraft is. Look here: (http://forum.avsim.net/topic/397227-md-11-bounce/) to read more about stability and center of gravity on the MD-11.

 

 

How do pilots fly the aircraft when it's empty?

 

The MD-11 has the option of carrying ballast fuel in any fuel tank (main, auxillary, or tail). You can select this via the INIT page 3 on the FMS.

Some airplanes nn to carry some sort of ballast, for example one carrier I worked for used a spear aircraft tire in rear cargo on BAC1-11. I have also seen sand bags used as well.

Thanks for your replies, interesting, I'll check out those links.

I often put a couple of containers in the forward cargo hold to get the CoG in limits.

 

Best regards,

Robin.

The MD-11 has an aft center of gravity. The more forward the center of gravity is, the more stable the aircraft is. Look here: (http://forum.avsim.net/topic/397227-md-11-bounce/) to read more about stability and center of gravity on the MD-11.

Only when flying empty the MD-11 has an aft centre of gravity ( tailheavy ). Due to the fact that there is lot more fuselage before the wing compared to aft of the wing the MD-11 tends to get noseheavy when loaded. Cargo aircraft suffer the most from this. As there is more fuselage before the wing there is also more cargo in front of the wing. You already concluded that the MD-11 has difficulty flying empty. The (cargo)aircraft also has difficulty when flying full. What you would do is make sure you have heavy and light pllts and place the heavy ones near the tail ( making sure you do not tip the aircraft in the loadingprocess) or load ballast(fuel)

 

B rdgs Dick

 

I often put a couple of containers in the forward cargo hold to get the CoG in limits.

 

I did the same thing Robin and it definitely works. Just click on one, two or three until the red lettering goes away and you should be good to go.

For what it's worth, to make it a little more realistic, you should use ballast fuel to properly balance the aircraft.  However, occasionally an airline will keep certain items with the aircraft.  Colgan's SAABs, as an example, used to always have engine covers, and various other items stored in the lower cargo section of the aft bin (not much weight in that case, but something that could be moved around as needed).  Other times, it's ballast in the form of sand bags (in the case fuel cannot be used as ballast), or an aircraft part.