# Frame of reference in elevator

I have a conceptual question that I have trouble understanding.

An object at the end of a rope is attached to the ceiling of an elevator. If the elevator is allowed to free-fall and hit the ground, at impact the tension of the rope is greater than if the elevator was standing still.

I would like to know why in the equation below, the acceleration is positive for $m\vec{a}$

$$T - mg = ma$$

Is this because to the object at the end of the rope, the elevator appears to be accelerating upward? Why is the acceleration not negative, since the elevator was free-falling?