CEN11LA327

While en route to the destination airport, the pilot noted fluctuation in the engine speed. He diverted to a nearby airport and detected smoke, which increased in intensity. While performing an emergency landing to a highway, the airplane's nose landing gear would not extend. The pilot landed the airplane, which slid to a halt. A postaccident examination revealed thermal distortion to the airplane's nose gear door, which impeded normal operation of the nose landing gear. Clamps on the turbocharger's intermediate exhaust crossover tube were found to be unsecured, which would allow exhaust gases to damage the engine's accessories. The examination also found signatures of thermal distress to the fuel flow transducer and fuel flow transducer line. The unsecured clamps and heat signatures were consistent with exhaust gases compromising the fuel flow transducer line, which resulted in a source of ignition and fuel for the in-flight fire. No additional preimpact mechanical malfunctions or failures were found that would have precluded normal operation. A review of maintenance logbooks noted that a propeller strike had occurred about 3 months before the accident and that repairs were completed about 1 month later, when the engine, including the turbocharger, was removed, cleaned, and inspected. The airplane had flown about 4 hours since the repair.

On May 7, 2011, at 2008 central daylight time, a Piper PA 46-350P airplane, N80JB, experienced an inflight fire near Chico, Texas. The airline transport pilot, the sole occupant, was not injured. The airplane sustained substantial thermal damage. The airplane was registered to and operated by Christian Air Brotherhood, Wichita Fall, Texas, under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which operated on a visual flight rules flight plan. The flight originated from Fort Worth about 1950. According to a statement provided by the pilot, the airplane was in cruise flight at 4,500 feet mean sea level, when he detected a change in engine noise along with fluctuations in the engine speed. The pilot started to divert to the nearest airport, when the engine began to run rough. Shortly thereafter, the pilot smelled, and saw smoke enter the airplane cabin. The smoke increased and the pilot elected to perform a forced landing on a highway. The airplane's nose landing gear did not extend and the airplane slid to a stop on the main landing gear and fuselage nose section. A postaccident examination of the airframe and engine was conducted by the members of the National Transportation Safety Board (NTSB), as well as technical representatives from the Piper Aircraft Company and Lycoming Engines. The examination revealed substantial damage was sustained to the airplane's forward fuselage and firewall. Distortion from heat was noted to the airplane's nose gear door, which impeded normal operation of the nose landing gear. Clamps on the turbocharger's intermediate exhaust crossover tube were found unsecured. The NTSB's fire investigator found signatures of thermal distress to the fuel flow transducer and fuel flow transducer line. No additional preimpact mechanical malfunctions or failures were found that would have precluded normal operation. A review of maintenance logbooks noted that a propeller strike had occurred in early February 2011. Repairs on the airplane were completed May 3, 2011, when the engine was removed, cleaned, and inspected. The pilot reported that the airplane had only flown four to five hours since the airplane had been returned to service.