You are using the numbers incorrectly: f=ma. a is acceleration, not speed. And m is mass, not weight. So all the thrust and weight can tell you is how fast the plane accelerates, not what its top speed is. Top speed is determined by drag.What I dont undersatnd is how the Aircraft gets enough speed in this equation. 14675.72745/34650 = 0.423541918m/s = 1.524kmph. Does the Linear Velocity add? I tried this in my model and It worked too fast. Does rpm come in? If so, then force = 660407.7N, giving it a velcocity of 19m/s = 68.61kmph.
Thos numbers tell us....
a=f/m = 14675/(34650/9.8)=
....that the airplane accelerates at 4.15 m/s/s, which sounds reasonable to me.