Beech 1900
Flight Crew Instrument; Flight Crew Flight Instructor; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Aircraft Equipment Problem Less Severe
Flight Crew Landed As Precaution; Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport
Aircraft
While conducting a training flight we were conducting stall maneuvers. The first one was a departure stall. When the FO reduced power a momentary compressor stall occurred between 1000 and 500 [FT-LBS of Torque] (LEFT Engine). Engine did not flame out. We terminated the training flight and was given clearance to descend to 8000 ft. I began the descent and upon power reduction the left engine had another compressor stall this time with a bright white flash outside the capt side window coming from the exhaust area right side. We decided to [advise ATC] and return to [departure airport]. At approximately 4000 ft another stall/white flash was seen at approximately 800 [Ft-Lbs of Torque]. The auto ignition had been armed by this point. Landed and CFR noted smoke coming from left engine during taxi.
The Captain of a Beech 1900 reported several engine compressor stalls during a training flight.