Auburn, AL, USA
N3420U
CESSNA 182F
The airplane was approximately 2,700 feet above ground level when the engine stopped producing full power and the airplane began to lose altitude. The pilot elected to land on a road and the airplane subsequently impacted an automobile. No preimpact mechanical anomalies of the engine were noted; however, examination of the muffler assembly revealed that the right internal baffle cone had separated from the surrounding structure. It was possible for the separated baffle cone to partially block the exhaust exit; however, its position as found would not have resulted in a loss of engine power. The airplane had been operated for about 2 hours since its most recent annual inspection, which was performed about 5 months prior to the accident. Due to the amount of damage observed to the fracture surfaces of the baffle cone, it was likely that the fracture occurred prior to the annual inspection. Inspection guidance used by the maintenance facility that performed the annual inspection included an inspection of the muffler, heat exchange, and baffles.
On February 27, 2011, about 1306 central standard time, a Cessna 182F, N3420U, operated by a private individual, was substantially damaged when it collided with a vehicle during a forced landing, after it experienced a partial loss of engine power while in cruise flight near Auburn, Alabama. The private pilot and two passengers in the airplane were not injured, and the two occupants in the automobile received minor injuries. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight, which originated at Moton Field Municipal Airport (06A), Tuskegee, Alabama, around 1235. The flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. According to the pilot, he was flying above Auburn, heading northbound about 2,700 feet above ground level (agl), when the airplane experienced a loss of engine power. The engine continued to operate, but it did not produce enough power to maintain altitude. While performing the engine out emergency procedures, he identified a road where the airplane could land. When the airplane was approximately 200 feet agl, the pilot noticed an automobile traveling in the same direction as the airplane. After landing, the airplane's right horizontal stabilizer impacted the back of the automobile and the automobile impacted the right side of the fuselage. Both the automobile and the airplane veered right, and came to rest in a ditch on the right side of the road. The airplane came to rest in a nose low and right wing low position. Both wings remained attached to the fuselage and the wing tips exhibited crush damage. The empennage remained attached to the airplane with visible damage to the right horizontal stabilizer. The airplane sustained substantial damage to the wing spar, right side of the fuselage, and the firewall. All engine mounts were broken and the propeller remained attached to the engine. A postaccident examination of the airplane conducted by a Federal Aviation Administration (FAA) inspector revealed that the fuel system and ignition system contained no anomalies that would have precluded normal operation. The carburetor was disassembled with no anomalies noted. He also inspected the fuel that was drained from airplane for contamination, with none noted. Both wings were drained of approximately 50 gallons of fuel total. The inspector removed the muffler assembly, and noted that one of the two baffle cones located inside the muffler was separated, and was lodged between the left muffler cone and the can assembly. Maintenance records indicated that the right end cap of the muffler was weld repaired on May 1, 1999. On July 23, 2000, the right side of the muffler was repaired again, which was about 360 flight hours prior to the accident. Further examination of the muffler assembly by Cessna Aircraft Company, under the supervision of an FAA inspector identified the muffler by a data plate as a Nicrocraft p/n CEM0007, s/n 7-2045, manufactured by Wall Colmonoy Corporation of Oklahoma City, Oklahoma. The muffler right baffle cone was found separated from the inlet tube at the end plate subassembly. Portions of the muffler were cut away to examine the end plates, inlet tube, and the cones. Examinations showed that the right cone was separated from the inlet along a circumferential fracture through the cone inlet tube that connected the cone to the muffler end plate. The fractured cone and inlet tube exhibited deformation. Significant modifications had been completed to the muffler which included weld repairs and replacement of both the left and right ends of the muffler assembly. The modified muffler assembly did not match the manufacturers engineering drawing of the muffler assembly. In addition, the separated right baffle cone was lodged between the muffler can and the left cone baffle, and it exhibited recent scoring and wear damage. The examination also revealed that the dislodged right cone could partially block the exhaust exit. Due to heavey degradation of the fracture surfaces, the manner in which the baffle cone fractured could not be determined. According to FAA records, the airplane was manufactured in 1963, and equipped with a 230-horsepower, Teledyne-Continental Motors O-470 series engine. The FAA inspector examined the airplane's maintenance records and noted that the airplane had been operated for about 2 hours, since its most recent annual inspection, which was performed on September 16, 2010, at a recorded tachometer of 3010.3 total hours of operation. An inspection card from the maintenance facility that completed the most recent annual inspection read "Piper Aircraft Corporation Inspection Report," and it indicated to "inspect muffler, heat exchange and baffles." That checklist item was checked off by the mechanic who performed the annual inspection on the airplane. An aircraft exhaust system inspection checklist provided by the muffler assembly manufacturer included "Look inside mufflers for broken baffles and tubes. They can restrict the outlet and cause power loss." The Cessna 182 Service Manual stated, "Inspection of the exhaust system should be thorough because the cabin heating system uses air heated by the heat exchangers of the exhaust system. Since exhaust systems of this type are subjected to burning, cracking, and general deterioration from alternate thermal stresses and vibrations (comparable to those affecting automotive mufflers), inspection is important and should be accomplished every 100 hours of operation." According to FAA records, the pilot held a private pilot certificate with a rating for airplane single-engine land. His most recent third-class FAA medical certificate was issued in June 2007. The pilot reported 244 total hours of flight experience, of which, 31 hours were in the same make and model as the accident airplane.
A loss of engine power due to an internal failure of the muffler that was not detected by maintenance personnel.
Source: NTSB Aviation Accident Database
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