PLT STRUCK FOUR RWY EDGE LIGHTS ON DEPARTURE FROM MTH.

Narrative

WHEN I TOOK OFF IN THE PLANE FROM MARATHON; FL (MTH); I HAD UNFORTUNATELY RAN OVER 4 OF THE R RWY SIDELIGHTS. IT APPEARS THERE WAS MINIMAL AND REPAIRABLE DAMAGE TO THE PLANE. THERE WERE A COUPLE SMALL DINGS IN THE R PROP THAT APPEAR TO BE SMALL ENOUGH TO BE BLENDED/SMOOTHED OUT. THE DINGS WERE FROM THE BROKEN GLASS FROM THE LIGHTS. THE LIGHTS ARE DESIGNED TO BE LOW ENOUGH TO THE GND SO THAT THE PROP WILL NOT HIT THEM. THE SIDELIGHTS ARE ALSO DESIGNED TO BREAK OFF TO MINIMIZE ANY DAMAGE TO ACFT THAT RUN OVER THEM. THE ONLY OTHER MINOR DAMAGE WAS TO THE BRAKE DEICE MANIFOLD; WHICH WAS SLIGHTLY BENT. I WILL REPLACE IT. HOW DID IT HAPPEN? DURING THE NIGHT TKOF FROM MARATHON; I DID NOT PICK UP THE INITIAL ACFT DRIFT TO THE R SIDE OF THE RWY WHERE THE RWY SIDELIGHTS ARE LOCATED. I WAS SCANNING THE PWR GAUGES TO ENSURE THE CORRECT PWR WAS SET AS I WAS INCREASING THE PWR LEVERS TO REACH TKOF PWR. I STOPPED THE DRIFT BUT IT WAS NOT IN TIME TO AVOID THE SIDELIGHTS. THE R TIRES ARE ABOUT 10 FT TO THE R FROM WHERE I SIT AND THE ACFT NOSE AND R ENG BLOCKED MY DOWNWARD VIEW SO I DID NOT REALIZE I WAS GOING TO HIT THE SIDELIGHTS. DRIFT ON TKOF IS CAUSED BY INCREASING PWR; WHICH INCREASES THE ENG TORQUE ON THE PLANE DURING PWR ADJUSTMENT; ESPECIALLY WHILE MOVING THE PWR LEVER FROM IDLE TO TKOF PWR DURING THE TKOF ROLL. ANOTHER REASON I DID NOT RECOGNIZE THE R DRIFT AND PUT IN AN IMMEDIATE CORRECTION BACK TO CTRLINE WAS THAT FOR A FEW SECONDS THE R SIDELIGHTS APPEARED TO BE A LIGHTED CTRLINE AND WAS MOMENTARILY CONFUSING. ONCE I HAD THE PWR SET AND MY COMPLETE FOCUS WAS OUTSIDE THE WINDOW FOR THE TKOF; IT APPEARED LIKE I WAS JUST L OF A LIGHTED CTRLINE -- IT WAS ACTUALLY THE WHITE R RWY SIDELINE AND SIDELIGHTS. UNLIKE THE L SIDE OF THE MARATHON RWY WHERE THE SIDELIGHTS ARE AT THE EDGE OF THE RWY; THE R SIDELIGHTS ARE PLACED ON THE RWY APPROX 50 FT IN FROM THE TRUE SIDE OF THE RWY (WHERE THE RWY PAVEMENT STOPS). SO LOOKING OUTSIDE; IN THE DARKNESS OF NIGHT; FOR THOSE FEW MOMENTS IT APPEARED AS IF I HAD 60 FT MORE PAVED RWY TO MY R SIDE. THIS MOMENTARY CONFUSION CAUSED ME TO DELAY THE CORRECTION BACK TO CTRLINE AND; THEREFORE; RUN OVER THE SIDELIGHTS.