As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER DEPARTURE FROM MIA THE PILOT EXPERIENCED A 400 POUND DECREASE IN ENGINE TORQUE ALONG WITH A DECREASE IN POWER AT 800FT AGL. THE PILOT DECLARED AN EMERGENCY AND AIR TURNBACK TO MIA. THE PILOT LANDED THE AIRCRAFT WITHOUT FURTHER INCIDENT.