I saw a F-104 fly at Ozark Mountain Jets that was a pretty heavy plane and the Funsonic pushed it along at a pretty good pace.. Not bad for a light turbine with 12 lbs. thrust...If you want to see which F-104 I am talking about go to the post about the OMJ fly and look for the F-104 with a natural aluminum covering job on it. I am guessing the plane weighed in at around 17 to 19 pounds and this 12lb thrust Funsonic that as I remember weighs only 1 1/2 pounds did a good job with it....