The story sure is exciting. But when you're ready to work on answering the question, you can ignore everything before the assumptions.
-- When the pilot hit the snow, he was allegedly falling at 50 m/s.
-- His mass is 85 kg.
-- So his kinetic energy was (1/2) (mass) (speed squared) =
(1/2) (85) (50)² = 106,250 joules
-- That's the energy that something else has to absorb in order to
reduce his speed to zero.
-- How far he fell, or what size crater he made in the snow, are irrelevant.