Guys! Hey guy? Just do what I do with my very fly whale, my mania of decentralizyng center of mass just for build 4 atmo engines BELOW wings and not in the middle, always result in some of both: 1-stability problems uping the nose of ship dangerously or: 2- Pushing de nose down. I try all, realign all engines, follow some tips of a lot "specialists" in aeroplanes, try add a lot of rcs thrusters (because as less atmosphere, less control about my dear Espinhenta I have), but it was just I turn on rocket mode and in matter of seconds happen a catastrofic lost of control (almost till splashdown in ocean), always the same think, when I am about to give up and literatly delete all saved versions, I think: "Well.. If there are to much thrust going from down of the ship, but, JUST A LITTLE BIT in comparisson with all thrust that engines could generate, WHY NOT PUT JUST ONE OR 2 LITTLE RADIAL ENGINES! THEY EVEN ARE ORANGE AND STYLIST! WHY NOT TRY?!" So, I put 2 rockomax at very middle (dorso) above the plane, and just for garantee more 2 of the same engines BELOW rocket engines, but almost in the center line just in case the thrust of the first 2 engines be much stronger, ok, result it was: THE BLACKBIRD TURN IT INTO A PERFECT AEROSPACE SHIP!! I swear guys, in the moment I turn the little 20kn engines, alll look like heaven! Looks like never some part it was builded far of center line!! But.. Is still a difficult plane to pilot, "she" (Espinhenta) claim/drain alll talent a pilot should have!! Lol But, in "aeroplanes mode", far away from vertical rockets, I'm just a newbie anyways!! Still thinking: its not so hard just try put one engine and set one key in action groups for the opossite side the nose points, dont you guys, think?! Just 0,09t but the rest of the "girl" is aalll very very light weigth (allways my major concern!)