19990527005839A

Acft crashed in a riverbed, the pilot has serious injuries, the passenger suffered fatal injuries, the acft was destroyed, other circumstances are unknown. (From .4) on may 27, 1999, at 0710 hours mountain standard time, a Cessna 180J, N2660M, collided with electrical transmission lines and crashed in Wickenburg, Arizona. The aircraft was destroyed and the commercial rated pilot received serious injuries, while his private pilot rated passenger sustained fatal injuries. The aircraft was being operated as a personal flight under 14 CFR part 91 of federal aviation regulations by the pilot/owner when the accident occurred. The flight originated from the moreton airpark, Wickenburg, Arizona, about 0700 on the morning of the accident. Visual meteorological conditions prevailed at the time and no flight plan was filed. The pilot reported that he and his passenger had taken off from runway 31 at moreton airpark and had made a right turn to a southeasterly heading. Their intent was to fly down the hassayampa riverbed before returning to moreton. The purpose of the flight was to demonstrate to the passenger, who was also a certificated airframe and powerplant mechanic, a symptom the aircraft had developed after he had installed new fuel bladders. After takeoff, the pilot said that they had climbed to between 3,000 and 3,500 feet MSL and were discussing the aircraft symptoms when he noticed a bright flash. His next recollection was of talking to paramedics. A witness located near the accident site, reported seeing an aircraft flying down the hassayampa riverbed about 10 feet. The aircraft then disappeared from view but a few seconds later she heard the sound of a crash. When safety board investigators arrived at the site, they noted that six aluminum electrical transmission lines had been broken. The location of the wires was 33 degrees 59.90 minutes north latitude and 112 degrees 44.106 minutes west longitude. The lowest three wires were 24 feet higher than the riverbed at the lowest point. The next set of three wires were 3 feet higher. Finally, there was a set of two high-tension lines another 3 feet higher than the second set of transmission wires. Wreckage was strewn along a 971-foot debris path that led from the wires to the aircraft fuselage. The debris path was on a 120-degree magnetic bearing from the first point of impact to the final point of rest. The fuselage was located 33 degrees 59.053 minutes north latitude and 112 degrees 43.961 minutes west longitude. There was evidence of "oil canning" on the top of the cockpit. The crash site was 5 miles from the departure airport and was on a magnetic bearing of 101 degrees from that location. The right wing was separated from the fuselage at the wing root and the fuel bladder was ruptured. The left wing remained attached to the fuselage. When the left wing was removed from the fuselage for recovery, investigators noted that several gallons of fuel were present in the bladder. The fuel was blue in color and had an odor consistent with aviation fuel. There was no evidence of contamination. All flight control surfaces were found and control continuity was established from the cockpit to each. Horizontal indentations, consistent in size to the aluminum transmission line, were found on the leading edge of both wing struts. A broken section of aluminum wire was found wedged around the top of the left strut. The horizontal stabilizer was found with -5 degrees of trim. The aural stallwarner failed to produce a sound when tested. The engine was separated from th e airframe and all the supporting engine mounts were fractured. The crankshaft was hand rotated and mechanical continuity was established from the propeller flange to the accessory section. The valve covers were removed and valve action was observed at each cylinder. A thumb compression check was performed and both magnetos produced a spark from their respective plug wires. The carburetor was separated from the engine; however, the bowl contained fuel. The screen was clean and there was no evidence of contamination. The mixture control was separated from the carburetor with visible impact marks. It was found in the "lean" position. The gascolator was separated from the firewall and was clean with no evidence of contamination. The fuel and vent lines were clear and unobstructed. The fuel selector was in the "both" position.(-23) on 05/27/99 at approx. 0700 hrs a Cessna 180J(N2660M) was flying low over a river bed near Wickenburg, AZ. The aircraft struck powerlines that went across the river bed. The aircraft struck the lines at level flight and at a high rate of speed. Various pieces of the airframeand engine were scattered over an area of approx. 200 yards. Two occupants on board one serious(monaco) and one fatal (haggett).