On September 21, 2001, about 1730 Alaska daylight time, a wheel-equipped Piper PA-32R-300 airplane, N4352F, sustained substantial damage during landing at the Tanana Airport, Tanana, Alaska. The airplane was being operated as a visual flight rules (VFR) on-demand charter flight transporting mail under Title 14, CFR Part 135, when the accident occurred. The airplane was owned by Harold Esmailka, and operated by Tanana Air Service, Inc., Fairbanks, Alaska. The solo commercial pilot was not injured. Visual meteorological conditions prevailed, and company visual flight rules (VFR) flight following procedures were in effect for the flight from Fairbanks to Tanana. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge on October 2, the director of operations for the operator reported that while en route to Tanana, the accident pilot's intended destination, all electrical power was lost. He added that the accident pilot elected to proceed to his destination, and during the landing roll, the left main landing gear collapsed. He said that the left wing struck the surface of the runway, and sustained substantial damage to the left main wing spar, and two nose ribs. The pilot submitted a written report to the NTSB dated October 12, 2001. In his written statement, the pilot reported that when he was about 26 miles from the Tanana Airport, be began to note telltale signs of an electrical failure. He added that the airplane's instrument panel-mounted ammeter indicated zero, so he shut off all of the airplane's electrical equipment. He noted that when he arrived at the destination airport, he placed the landing gear extension handle in the down position, but the gear failed to extend, and the landing gear down lights did not illuminate. He reported that he followed the flight manual procedures for an emergency gear extension by slowing the airplane to 87 knots, holding the landing emergency gear lever in the "EMERGENCY DOWN position, while fish-tailing the airplane. In an attempt to determine if the landing gear was down, he checked the airplane's shadow and noted that the gear appeared to be down. During touchdown the left main landing gear collapsed, and the left wing struck the surface of the runway. The Piper PA-32R-300 is equipped with a retractable tricycle landing gear, which is hydraulically actuated by an electrically powered reversible pump. The emergency landing gear extension handle, when used for emergency extension of the landing gear, manually releases hydraulic pressure to permit the gear to free fall with spring assistance on the nose gear. In the case of a complete electrical failure, the landing gear down lights will not illuminate. A Federal Aviation Administration, Airworthiness Inspector, Fairbanks Flight Standards District Office, reported that a postaccident examination of the airplane revealed that the voltage regulator failed, which subsequently led to the loss of electrical power.