NTSB Factual Report

On December 18, 2016, about 1500 central standard time, a Bellanca 17-30A airplane, N4204B, was substantially damaged during a forced landing near Blaine, Minnesota. The pilot was not injured. The airplane was registered to and operated by Bel Vik LLC under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Day visual meteorological conditions prevailed for the flight, which departed about 1420 from Range Regional Airport (HIB), Hibbing, Minnesota, and was destined for Flying Cloud Airport (FCM), Minneapolis, Minnesota.

The pilot stated the airplane was launched from a heated hangar at FCM. After landing at HIB, two passengers were deplaned. The airplane remained on the ground at HIB about 15 minutes, with no fuel added. During departure from HIB, the temperature was minus 6 degrees F.

While in cruise flight at 2,500 ft msl, at an estimated temperature of minus 10 degrees F, the engine lost power. After the pilot switched fuel tanks and turned on the fuel boost pump, engine power was restored. Due to uncertainty with fuel status, the pilot diverted towards Anoka County–Blaine Airport (ANE), Blaine, Minnesota. Approaching ANE, the engine began to knock and subsequently seized. The pilot executed a forced landing onto a road, during which the airplane's left wing impacted a sign.

Examination of the engine at the accident site revealed the top portion of the right and left crankcases were broken, with crankcase material missing and damaged internal engine components visible, including a fractured connecting rod cap. The engine breather tube was frozen over, with no alternate breather hole present. The propeller shaft seal was partially protruded. The engine, which has a normal oil capacity of 12 quarts, contained about 5 quarts of oil. Most of the oil loss occurred through the holes in the crankcase, with some oil loss through propeller shaft seal.

The engine was shipped to the Continental Motors facility at Mobile, Alabama. Examination revealed all rocker arms and shafts were undamaged and all valves were intact, with normal combustion signatures. The induction components, ignition components, and fuel pump were not damaged. The fuel pump was bench tested and performed within specifications.

Internal engine damage did not allow for rotation of the crankshaft. Following split of the crankcase, the Nos. 3 and 4 cylinder skirts were found to be mechanically damaged by internal components, with the Nos. 3 and 4 pistons wedged in their respective cylinders. Both crankcase halves were internally damaged by rotating components. The Nos. 3 and 4 connecting rods were damaged, with their respective rod caps separated. The remaining four connecting rods were not damaged. The Nos. 1, 2, 5, and 6 connecting rod bearings exhibited overlay fatigue, dirt embedment and corrosion. The No. 3 and 4 connecting rod bearings displayed significant heat distress and severe damage.

The crankshaft's No. 4 connecting-rod journal was severely damaged due to heat distress. The oil galleys and transfer tubes were examined with additional lighting, which revealed that no blockages were present. Each of the five main bearings were intact, with an insignificant amount of contamination. The transfer collar exhibited normal operation patterns.

The oil cooler was not damaged and the oil system vernitherm (thermostat) was removed and tested, with normal results. The oil pressure relief valve had evidence of an unapproved sealant on the oil pressure relief valve body. The engine was equipped with a reusable oil screen, versus a spin-on full flow oil filter. The reusable oil screen contained ferrous and non-ferrous metal contaminants.

The recommended oil change interval for an engine with a reusable oil screen was every 25 hours or 4 months, according to Continental Motors Standard Practices Publications. A review of logbooks prior to 2011 revealed a history of erratic oil changes, including intervals of 45, 48, 66, 80, and 84 hours.

The airplane was involved in a hard landing in 2011 and was not flown for about 5 years. After purchase by the current owner, an annual was performed on February 1, 2016, and an oil change occurred on August 8, 2016. Phillips 20-50WC oil, which has a pour point of minus 27 F, was utilized for both the annual and subsequent oil change.

NTSB Probable Cause

A total loss of engine power due to a lack of crankshaft lubrication to the No. 4 connecting rod journal.