SEA07LA172

During the first flight after installation of an overhauled engine, overhauled propeller and overhauled propeller governor, the airplane's engine lost power, and the pilot made a forced landing on an interstate highway in a major metropolitan area. During the landing, the airplane's left wing struck a car. The pilot stated that he selected the highway as a landing area "as everything else was rooftops." Examination of the engine revealed an uncontained catastrophic failure of the number four connecting rod. There was significant heat distress at the number four connecting rod, and adjacent components consistent with lack of oil lubrication. The oil dipstick did not register any oil in the sump, and a significant oil film was on the firewall and belly. The propeller governor was found installed contrary to the engine manufacturer's Parts Catalog and Service Instructions. A single gasket was used to mount the governor instead of the required plate sandwiched between two gaskets. A clear and evident oil path was seen from the edge of the single gasket. The improper governor installation allowed engine oil to leak overboard, resulting in a loss of lubrication and failure of the number four connecting rod.

On June 18, 2007, about 1845 Pacific daylight time, a Cessna 177RG, N2144Q, experienced a loss of engine power and struck a car during an emergency landing on Interstate 78 in Oceanside, California. The airplane sustained substantial damage, the private pilot was not injured, and the driver of the car sustained minor injuries. The pilot was operating the airplane under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed for the local personal flight and no flight plan was filed. The airplane departed McClellan-Palomar Airport in Carlsbad, California about 1735.

During a telephone interview conducted by the NTSB investigator-in-charge, the pilot reported that the purpose of the flight was to break in a newly overhauled engine that had just been installed in the airplane. The flight proceeded normally for approximately 1 hour and 10 minutes. All engine instruments were indicating "in the green." As the pilot headed back towards the departure airport, he heard a "loud bang," the engine lost power, and the cockpit filled with smoke. He opened windows and cracked his door, and the smoke dissipated. Once he regained visibility, the pilot selected Interstate 78 as his emergency landing location "as everything else was rooftops." He landed in the westbound lanes with the traffic, and the airplane's left wing struck a car.

A Federal Aviation Administration inspector examined the airplane and reported that the left wing sustained structural damage. Additionally, the inspector reported that there were holes in the engine case and the number four connecting rod was separated.

The airplane was powered by a Lycoming IO-360-A1B6D engine equipped with a dual magneto and a rear-mounted McCauley C290D3K/T12 propeller governor. Examination of the airplane's maintenance records revealed that the last annual inspection was completed on June 18, 2007. At the time of the annual inspection, an overhauled engine, overhauled propeller and overhauled propeller governor were installed. When the accident occurred, the airplane had flown 1.2 hours since this inspection.

On July 23, 2007, the engine was examined under the supervision of an NTSB investigator by a representative of Lycoming Engines at the facilities of Plain Parts in Pleasant Grove, California. The engine remained attached to the airframe by the engine mount. An uncontained catastrophic malfunction of the engine at the number four connecting rod was evident, which precluded hand rotation of the propeller. There was significant heat distress observed at the number four connecting rod and adjacent components consistent with lack of oil lubrication. The oil dipstick did not register any oil in the sump. A significant oil film was observed on the firewall and aircraft belly. The oil filter, converter plate gasket and oil lines within the engine compartment were found secure at their respective locations. Examination of the rear-mounted propeller governor revealed that it was installed with a single MS-9144-01 gasket. A clear and evident oil path was observed on the single gasket, where the gasket material was not compressed.

According to Lycoming Parts Catalog PC 406-1, pages 2-3, 2-4, the IO-360-A1B6D engine with a dual magneto requires two P/N 72053 governor gaskets and one LW-12347 propeller governor pad plate. Textron Lycoming Service Instruction SI-1438A dated December 9, 2005, states that the use of the plate sandwiched between two gaskets "is necessary with some propeller governors to eliminate the possibility of oil leakage between the propeller governor and the accessory housing."