Let us list out what we know from the question.
Initial Velocity
since the piton is 'dropped'.
Vertical Displacement of the piton D = 215 m
Acceleration due to gravity

Final Velocity

Using the equation,
and plugging in the known values, we get

Simplifying by taking square-root on both sides gives us

Thus, the speed of the piton just before striking the ground is 65 m/s.