As quoted if true............but rotor while flying on 1000 ft in steady course
had no chance to see above&behind and plank last data was:
2,700 ft Vertical Speed -1,536 fpm.
A descent of 1536 fpm seems very high for a C152, and comenced below a height where you would not generally enter a spin or spiral dive. Despite which you would make clearing turns first.
A glide, approach, or normal decent would be more likely to be 500, 600 fpm in a C152, sideslip slightly higher.