Mike Stone's A380 normally handles well. However, when I set it up for use with FS Passengers, it rotated on its own at 104 kts, scraped its tail on the runway and climbed at an angle of 50 degrees until it stalled.
Even trimming its nose down as much as possible only helped a little.
Funny that - I tried Mikes C130 - no passengers(!) - and have the same trouble with the aircraft pitching up of its own accord - in reply to my post "help with hercules" the guys suggested I should n't be taking off with flaps - but the pitch-up still happens with no flaps. I have cleared and reloaded but the trouble still persists
I've flown that C130 and does seem to be tail-heavy, but can be controlled by trimming it. The A380 is normal...until FPS is involved. It happens when fully loaded and evenly balanced cargo. I suspect their default A380 file misplaces the center of gravity. I have found several FSP .ini files that are seriously screwed up...such as having a plane at its MTOW with 99% fuel and no passengers or cargo aboard. I have even found some with weights 5,000 lbs greater than that on the aircraft's certification papers.
I am going to take a stab at changing some of those files.