"Montblack" wrote in message
...
Let's take this away from the light...

For the plane NOT to take off - the plane must have zero forward
movement/airspeed. According to the OP rules, in that state the belt is
stationary. [...]

See, this is where you went wrong. This little tangent is not about the
original post's rules. The original problem has been modified for the
purpose of entertainment, not enlightenment.