"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."
Please stop using a formula for motion under gravity in a vacuum in relation to the descent of aircraft falling through the air.
Air resistance is the dominant factor, downward velocity will stop increasing once air resistance equals weight. Erratic of course if tumbling, but far far slower than in a vacuum, where speed keeps increasing until impact.