THE PILOT REPORTED THAT WHILE MAKING AN APPROACH TO THE RUNWAY IN TWILIGHT CONDITIONS, HE WAS MORE FIXATED ON ALTITUDE, SPEED AND THE LOCATION OF THE THRESHOLD. THE PILOT DID NOT NOTICE THAT THE AIRPLANE WAS MISALIGNED WITH THE RUNWAY, AS THE RUNWAY IS ONLY EQUIPPED WITH THRESHOLD LIGHTS. THE AIRPLANE TOUCHED DOWN BETWEEN THE THRESHOLD LIGHTS AND TRAVELED OFF THE LEFT SIDE OF THE RUNWAY AND RAN INTO A DITCH.