A GROUND WITNESS OBSERVED THE AIRPLANE AT NIGHT, FLYING TOWARD THE AIRPORT AT A LOW ALTITUDE IN VFR CONDITIONS. SOON THEREAFTER, IT STRUCK A 45-FOOT-HIGH POWERLINE & CRASHED. THE ACCIDENT OCCURRED ABOUT 3-3/4 MILES WEST OF THE AIRPORT. AN EXAM OF THE WRECKAGE DISCLOSED NO EVIDENCE OF A PREEXISTING AIRFRAME OR ENGINE MALFUNCTION OR FAILURE. THE PILOT'S PRIVATE PILOT CERTIFICATE CONTAINED AN ENDORSEMENT THAT RESTRICTED HIM FROM FLYING AT NIGHT, SINCE HE HAD NOT RECEIVED ANY NIGHT INSTRUCTION BEFORE APPLYING FOR THE CERTIFICATE. A TOXICOLOGY CHECK OF HIS BLOOD SHOWED AN ALCOHOL LEVEL OF 0.18%.