DHC6 EXPERIENCE INFLT LOSS OF L ENG. SAFELY RETURN TO DEP ARPT.

Narrative

OUR ACFT TOOK OFF FROM THE ARPT. WE CARRIED 18 PAX BUT WERE ABOUT 1000 LBS LIGHTER THAN THE MAX GROSS WT. IT WAS MY LEG. THE CAPT WAS THE PNF. AFTER ABOUT 35 MIN FLT; I NOTICED THE L TORQUE GAUGE DROP TO 20 LBS SUDDENLY AND TO 0 LBS AND FELT A LITTLE YAW MOVEMENT TO L. THE CAPT NOTICED T5 GAUGE UP TO RED ARC. I HEARD L ENG TURBINE NOISE WENT SILENT. WE DID 'ENG FAILURE INFLT' PROCS. WE IDENTED L ENG FAILED AND SHUT DOWN THE L ENG. I HEADED TO ARPT DIRECTLY THROUGH THE 'SFRA FLYING FREE ZONE.' THE CAPT CONTACTED THE TWR; TOLD THEM WE HAD AN ENG FAILURE. 10 MI N OF ARPT; THE TWR CLRED US TO STRAIGHT-IN RWY 21. I COULD MAINTAIN ALT AT 9500 FT WITH 10 DEGS FLAPS. WE HAD ENOUGH TIME TO DO 'IN RANGE CHKLIST' AND 'BEFORE LNDG CHKLIST.' THE CAPT ASKED IF I WANTED HIM TO FLY; AND I REPLIED I WOULD FLY. SO HE SUPPORTED ME THROUGH THE FLT. ON THE APCH; THE CAPT REMINDED ME WE HAD ENOUGH RWY TO LAND. I MAINTAINED A LITTLE HIGHER ALT THAN NORMAL THROUGH THE FINAL APCH. THE WIND WAS LIGHT XWIND FROM W. I LANDED WITH SINGLE ENG UNEVENTFULLY WITH THE CAPT'S SUPPORT. AFTER LNDG; THE CAPT TAXIED WITH 1 ENG FAILED. WE DID THE RIGHT PROCS AND LANDED SAFELY. NOBODY WAS HURT. I BELIEVE NOTHING WAS WRONG WITH OUR PROCS DEALING WITH 1 ENG FAILURE.