FAILED TO REMOVE NOSE PLUG ON PREFLT. ATTEMPTED TKOF. RETURN LAND.

Narrative

I COMPLETED WHAT I THOUGHT WAS A THOROUGH PREFLT JUST PRIOR TO SUNRISE. GND PERSONNEL HAD LEFT AN INTAKE PLUG ON THE #2 ENG. IT WAS UNFLAGGED AND DIRTY; SO I FAILED TO NOTICE IT DUE TO THE DISTANCE OFF THE GND; AND THE POOR LIGHT. THE AGENT FAILED TO NOTICE IT AND I WAS INSTRUCTED TO START THE #2 ENG. IT STARTED AND RAN NORMALLY BY TAKING IN AIR FROM THE SLOT FOR THE INTAKE DEFLECTORS. WE MADE AN INTXN TKOF FROM A6. THE ENG ACCELERATED SLIGHTLY SLOWER THAN NORMAL; BUT HARDLY NOTICEABLE UNTIL WE WERE AT V1. AT THAT POINT IN TIME THE ENG COULD NOT KEEP ACCELERATING DUE TO ITS LIMITED AIR SUPPLY. SINCE WE WERE ABOVE V1; AND ROTATING; WE CONTINUED WITH THE INTENT TO TEARDROP BACK TO THE RWY. IT WAS NOW LIGHT ENOUGH FOR ME TO SEE THE INTAKE PLUG. SINCE ALL ENG PARAMETERS WERE NORMAL AND THE PLUG DID NOT APPEAR TO BE IN DANGER OF BEING SUCKED IN AS FOD (DUE TO THE REDUCED PWR AND THE PLUG'S DESIGN) I LEFT THE ENG RUNNING AT FLT IDLE. AT NO TIME WAS ANY ENG PARAMETER NEAR BEING EXCEEDED. UPON SHUTDOWN THE PLUG WAS EASILY REMOVED. PLUGS SHOULD BE MADE MORE VISIBLE! I SHOULD HAVE USED A FLASHLIGHT ON PREFLT. PEOPLE NEED TO BE AWARE THAT THE ENG WILL RUN QUITE WELL BREATHING THROUGH THIS ALTERNATE AIR SOURCE.