Yes, 40s is about right for an object released with no initial velocity.
If an aircraft pitches down, however, some part of the horizontal velocity becomes the initial velocity (100% if it goes vertical) so it will take less time even if it breaks up.
That's not right - but the point highlights that if the aircraft is pitched down and assuming the motors are still running the thrust is added to the gravitational acceleration so a is going to be > 9.81 m/sec squared.
What's the terminal velocity of a 777 pointed towards the centre of gravitational attraction?