HISTORY OF FLIGHT On April 1, 2001, about 0023 hours Pacific standard time, a Cessna 172N, N739WE, operated by Security Aviation of Hawthorne, California, was destroyed during the collision sequence with communication wires and terrain at Rialto, California. The commercial flight instructor rated pilot and passenger both received fatal injuries. Instrument meteorological conditions prevailed for the personal flight operating under 14 CFR Part 91, and no flight plan was filed. The accident flight was destined for Hawthorne. On March 31, 2001, the airplane had been the subject of a Federal Aviation Administration (FAA) alert notification (ALNOT), issued at 2210, for failure to cancel an instrument flight plan for a flight between Hawthorne and Rialto, California. The Rialto airport is uncontrolled. The pilot had obtained an FAA preflight weather briefing at 1551, for the flight to Rialto. According to the instrument flight plan information, the estimated time of arrival at Rialto was 1845. Subsequently, the airplane was located at the Rialto airport parking ramp by San Bernardino County Aero Bureau personnel located on the airport. The ALNOT was canceled at 2240. The pilot obtained a standard weather briefing for the return flight to Hawthorne at 2319. He was advised of airmets for IFR ceilings and visibilities for his route of flight. The operator stated that the pilot and passenger had flown to Rialto to visit with friends and were to return to Hawthorne. The pilot was a flight instructor for the operator and possessed airplane single engine land and instrument ratings. PERSONNEL INFORMATION On November 19, 1999, the pilot was issued a private pilot certificate at 113 total flight hours. On January 3, 2000, the pilot was issued an instrument airplane rating at 155 total hours, including 35 dual instrument hours. AIRCRAFT INFORMATION According to airplane logbook records, the last documented inspection occured on March 23, 2001, as an annual inspection performed at 9,295 total flight hours. The last recorded altimeter and static system tests required by FAR 91.411 and Part 43 appendix "E" was accomplished on June 4, 1999. METEOROLOGICAL INFORMATION At 2353, the Ontario International Airport, located 11 miles southwest of the accident site, was reporting: wind 240 degrees at 5 knots; visibility 2.5 statute miles; mist/light fog; overcast at 700 feet; temperature 55 degrees Fahrenheit; dew point 55 degrees Fahrenheit; and the altimeter was 29.92 inHg. At 2353, the Riverside Municipal Airport, 11 miles south, was reporting: wind 290 degrees at 4 knots; visibility 1.5 statute miles; mist/light fog; overcast at 300 feet; temperature 55 degrees Fahrenheit; dew point 55 degrees Fahrenheit; and the altimeter was 29.92 inHg. WRECKAGE AND IMPACT INFORMATION The wreckage was examined by the Safety Board investigator about 3 hours after the accident occured. The weather was near total obscuration in fog and mist. The wreckage was located about .80 mile northwest of the airport. At the accident site, communications wires were severed from their poles that were 23 to 26 feet in height. The communication service went off line at 0023. The wires were strewn across Highland Avenue from the north to south. Wreckage debris consisting of window Plexiglas, left flap section, window frame, and interior molding was scattered from the broken wires south. The wreckage path was measured about 150 degrees over about 200 feet, missing power lines on the south side of Highland Avenue. The left wing and lift strut were located within 26 feet south of Highland Avenue, with fire damage to the aft wing root section and flap. The main wing spar carry through and cabin top skin were located about 58 feet south. The fuselage, right wing, and empennage were located 192 feet south of Highland Avenue pointing about 100 degrees. The entire cabin section from the firewall to aft of the baggage area and right wing root were destroyed by post accident fire damage. A propeller blade exhibited leading edge gouging, chordwise striations, and trailing edge "S" bending. MEDICAL AND PATHOLOGICAL INFORMATION On April 3, 2001, the San Bernardino County Medical Examiner performed an autopsy on the pilot. During the course of the procedure samples were obtained for toxicological analysis by the Federal Aviation Administration Civil Aeromedical Institute in Oklahoma City, Oklahoma. The results of the analysis were negative for carbon monoxide, ethanol, and drugs. ADDITIONAL INFORMATION On July 1, 2002, the wreckage was released to the insurance company representative for the owner. Radar data was obtained from Southern California Tracon and a plot was generated by a private vendor for Cessna Aircraft Company. A copy of the plot is attached to this report. It shows the airplane circling back over the airport and heading northwest. The highest altitude before coverage is lost is 1,700 feet mean sea level.