DEN06LA062

The pilot reported that while in cruise flight, the engine manifold pressure dropped followed by a loss of oil pressure. The pilot elected to divert to a nearby airport. During the descent, the engine began to fail. The pilot elected to force land the airplane on a road. While setting up for the landing, the engine seized. During the landing roll, the airplane's right wing struck a road sign, causing substantial damage to the airplane. An initial examination of the airplane showed oil adhering along the full length of the bottom fuselage. The oil originated at the engine right side exhaust pipe. An examination of the airplane's engine showed the right hand turbocharger impeller blades were worn at the tips. Some of the blades were fractured. There was also excessive play noted in the compressor assembly. An examination of the turbocharger was conducted at the NTSB Materials Laboratory. The examination determined that the impeller's aluminum bearings were heavily worn and distorted. There was no sign of overheating in the bearings. Attempt to do a Rockwell hardness test were made, but accurate readings could not be gained due to the softness of the metal. Further examination showed damage to the oil seal at the impeller shaft.

On April 13, 2006, about 1610 mountain daylight time, a Piper PA-46-350P, N82LL, was substantially damaged when it struck a road sign during a forced landing 4 miles west of Hope, New Mexico. Visual meteorological conditions prevailed at the time of the accident. The personal flight was operating on an instrument flight rules flight plan under the provisions of Title 14 CFR Part 91. The private pilot on board the airplane was not injured. The cross-country flight originated at Las Cruces, New Mexico, and was en route to Clovis, New Mexico.

The pilot said he was cleared to flight level 230. Going through 21,000 feet, the airplane experienced a "reverse surge," that is, "a noticeable loss of power." The pilot said he then felt a bit of a surge, followed by a second loss of power. The pilot then noticed that the airplane was losing cabin pressurization. He said he called center (Air Traffic Control - ATC) and told them that he had an engine surge and required an immediate descent. ATC cleared his airplane to 11,000 feet and direct to Artesia, New Mexico. The airplane was approximately 35 mile south of Roswell, New Mexico.

The pilot said he was flying in instrument conditions and was busy flying the airplane and looking around the instrument panel for other system failures. He said he knew that he was losing power and that the cloud bottoms were at 13,000 feet.

The pilot extended the airplane's landing gear and performed an "aggressive" descent at 2,000 to 2,500 feet per minute, down to 11,000 feet. When he leveled off at 11,000 feet, the pilot noticed the reduced manifold pressure (mp) and then, that the oil pressure gauge read just below 70 PSI. The pilot added throttle but noticed no noticeable increase in manifold pressure. The mp was about 20 inches.

The pilot said the airplane flew for another 8 minutes, then the engine lost all oil pressure. He said the airplane flew another 4 minutes without oil pressure. The pilot elected to land on a road. He said that he was about 800 to 1,000 feet above the road when the engine started to come apart. He said that up to that point, his propeller was wind milling. The pilot pulled off the mixture and turned off the magnetos. Right after that, the engine seized and the propeller froze. The pilot said after the engine seized, the airplane went down fast. The pilot performed a forced landing on the road. During the emergency landing, the airplane's right wing struck a road sign, causing substantial damage to the airplane.

An examination of the airplane at Artesia, New Mexico, showed oil streaks running along the full length of the bottom fuselage. The oil originated at the engine right side exhaust pipe. The right wing showed impact damage to approximately 10 feet of the wing's leading edge, beginning at mid-span extending outboard, and aft approximately 12 to 14 inches. The right wing tip was broken aft longitudinally.

An examination of the airplane's engine showed the right hand turbocharger impeller blades were worn at the tips. Some of the blades were fractured. There was also excessive play noted in the compressor assembly. The turbocharger was disassembled and examined at Kelly Aerospace Corporation, Fort Deposit, Alabama, on June 12, 2006. The examination showed that in addition to the impeller disc damage, there was scoring of the impeller shroud, damage to the turbine and exhaust housing, mashed bearings, and unidentified debris found between the impeller and turbine blades.

The turbocharger components were examined at the NTSB Materials Laboratory in Washington, DC, on August 31, 2006. The debris noted between the impeller and exhaust turbine blades was consistent with exhaust products. An examination of the impeller's aluminum bearings showed heavy wear and distortion. There was no sign of overheating in the bearings. Further examination showed damage to the oil seal at the impeller shaft.