Lexington, NC, USA
N242MB
CIRRUS DESIGN CORP SR22
The commercial pilot was conducting a personal cross-country flight. The pilot reported that, while en route to his destination at a cruise altitude of about 5,000 ft mean sea level, the engine "failed." He flew the airplane toward an open field and deployed the ballistic recovery parachute. He subsequently conducted a successful landing in the field. An examination of the engine revealed that the crankshaft had fractured between the No. 2 main journal and the No. 2 connecting rod journal. An examination of the crankshaft revealed that the fracture was due to fatigue that had initiated from multiple origins at the fillet radius between the No. 2 main journal and the cheek at the aft end of the journal. The fatigue initiated from surface damage that occurred due to the No. 2 main bearing shifting. The bearing likely shifted due to the improper tightening of the crankcase through bolt nuts and subsequent insufficient clamping force of the crankcase saddle surfaces. A review of the airplane's maintenance records revealed that the engine was last overhauled 775 total flight hours before the accident, and no records were found indicating that the through bolts had been removed since that time. It is likely that maintenance personnel improperly tightened the crankcase through bolts during the overhaul.
On October 22, 2014, at 0625 eastern daylight time, a Cirrus SR22, N242MB, registered to and operated by a private individual, deployed the Cirrus Airframe Parachute System (CAPS) following a total loss of engine power. The commercial pilot was not injured and the airplane sustained minor damage. Visual meteorological conditions prevailed for the personal flight conducted under Title 14 Code of Federal Regulations Part 91. The flight, operating under instrument flight rules, originated from Mc Gee Field Airport (24NC), Monroe, North Carolina, at 0600 central daylight time and was destined for Piedmont Triad International Airport (GSO), Greensboro, North Carolina. According to the pilot, while enroute to his destination, at a cruise altitude of 5,000 feet msl he contacted GSO approach and opened his flight plan. Shortly thereafter the engine "failed"; the pilot flew the airplane towards an open field and deployed the CAPS system. The airplane made a successful landing in the field. Examination of the engine revealed that the crankshaft had fractured between the number two main journal and the number two connecting rod journal. The number two bearing displayed bearing shift signatures and had completely extruded from the bearing support. The number one, two, three, and the number four bearing supports displayed fretting near the through bolt holes. There was no evidence of an oil starvation or lack of lubrication. Examination of the oil pump revealed that the drive gear was intact. The oil pump cavity contained light scratches. The oil pump gear teeth were intact and did not exhibited any anomalies. The oil pressure relief valve seat contained some metallic debris and the relief valve plate displayed signs of peened imprints around the seat area circumference. The oil filter was removed from the engine and the oil filter housing was cut open and the filter element was removed from the canister for examination. The oil filter element contained flakes and slivers from the damaged internal engine components. The oil sump drain plug was removed and the oil was drained from the sump; the amount was measured to be 8 quarts. The oil was dark in color and contained metallic debris. The oil sump was removed and sections of bearing were found in the sump along with metallic slivers and shavings. The oil pickup tube was bent and the screen was intact; metallic debris was noted on the screen. A review of maintenance records revealed that the Continental IO-550N7 engine was rebuilt by Teledyne Continental Motors on August 22, 2011. The engine accumulated 775 hours since factory rebuild and there is no record or evidence of the cylinders being removed since rebuild. The engine accumulated 200 hours since the last annual inspection dated November 8, 2013. Further review of records revealed that a 50 hour engine oil change was performed 69 hours prior to the accident on September 29, 2014. The crankshaft was removed sent to the NTSB materials laboratory for fracture analysis. An examination of the crankshaft revealed that the fracture was due to fatigue that initiated from multiple origins at the fillet radius between the second main journal and the cheek at the aft end of the journal.
Maintenance personnel's improper tightening of the crankcase through bolt nuts during reassembly of the engine at the last overhaul, which resulted in the failure of the crankshaft and the subsequent total loss of engine power.
Source: NTSB Aviation Accident Database
Aviation Accidents App
In-Depth Access to Aviation Accident Reports
