What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
While climbing through 21400 ft enroute to ksrq from kpbi a loud bang was heard followed by a left downward yaw. The aircraft began a hard shudder and was difficult to control. ATC was immediately notified of a mayday and request to return to pbi. No other lights warnings or cautions were displayed. The only indication of problems was the shudder and difficulty moving flight controls. After an uneventful landing and shutdown it was discovered that the LH engine upper cowling was missing and the lower cowl was hanging by a pipe on the lower side of the engine.
As the FAA filed it
WHILE CLIMBING THROUGH 21400 FT ENROUTE TO KSRQ FROM KPBI A LOUD BANG WAS HEARD FOLLOWED BY A LEFT DOWNWARD YAW. THE AIRCRAFT BEGAN A HARD SHUDDER AND WAS DIFFICULT TO CONTROL. ATC WAS IMMEDIATELY NOTIFIED OF A MAYDAY AND REQUEST TO RETURN TO PBI. NO OTHER LIGHTS WARNINGS OR CAUTIONS WERE DISPLAYED. THE ONLY INDICATION OF PROBLEMS WAS THE SHUDDER AND DIFFICULTY MOVING FLIGHT CONTROLS. AFTER AN UNEVENTFUL LANDING AND SHUTDOWN IT WAS DISCOVERED THAT THE LH ENGINE UPPER COWLING WAS MISSING AND THE LOWER COWL WAS HANGING BY A PIPE ON THE LOWER SIDE OF THE ENGINE.