Ok, with the air resistance (noted here r) we have the following equations (S is speed, S0 is the vertical speed at the moment t0 when the plane stopped the engines:
For plane with the engines stopped on FE: Sp=S0+r(a(t-t0))2 - because the air resistance varies with square of the speed (I am simplyfing here). See, the air is accelerating the plane upwards, and the friction force will add to the original speed.
For Earth S=S0+a(t-t0)
Now the relative speed of plane to Earth will be Sp-S
That means Delta S= r(a(t-to)2-a(t-t0)
When this relative speed will be constant? When it will not be variable in time. So derivative of this function with the variation of time is zero.
That means r(a(t-to)/2-a=0
So the time when speed will be terminal (constant) t=2/r+t0 - so depends only of the resistance of the plane in air (given by it's shape and position).
If the plane starts its engines, then it will generate lift force. And the plane will not crash...