Open any aircraft.cfg file and check the moi_ entries:;Moments of Inertiaempty_weight_pitch_MOI = 1400.0empty_weight_roll_MOI = 1137.0empty_weight_yaw_MOI = 2360.0empty_weight_coupled_MOI= 0.0The above are from the default C172.Compare to the B747 default's entries:;Moments of Inertiaempty_weight_roll_MOI = 13352310empty_weight_pitch_MOI = 24223159empty_weight_yaw_MOI = 39531785empty_weight_coupled_MOI = 0Obviously, the Moments of Intertia (MOI) for the B747 are much higher than for the C172.If you aren't happy with the "mass feeling" for any a/c, simply increase all the moi_ values with the same proportional scalar value... ;)

There is a substantial difference in handling aircraft even in the same weight category, due to its mass, geometry, high/low wing, engine power and its location on the frame. They all feel different. I'm really surprised to hear that 747 feels like Cessna to you. Does driving Hummer feel same as Civic :) Cheers,

Thanks Bill for the info. I have tweaked ever so slightly the MOI's in the past with some success. Maybe what I'm trying to describe would be better illustrated by an aeronuatical engineer. I can't seem to cnvey properly, the aspect of mass between FS9 and real life. Then again I may be searching for answers a $50 buck program simply can't produce. :) S.V. Perhaps I was to literal. I was focusing only on the principle of mass. But saying the differences are marginal also make my point subjective which I was trying to avoid. In the area of mass, both seem alike while in other areas they do not. Maybe it's the programmer's little trick to make things seem they are "As real as it gets". I mean we're not discussing a $30 million dollar sim here or last I checked I didn't have one on my desk. :)Anyway, thanks all for your replies and insight. This is one white elephant that should now be laid to rest.Sticks

>In FS9, this feeling of