Fulton, TX, USA
N540JH
MX AIRCRAFT LLC MXS
The airline transport pilot reported that, while in cruise flight at 11,500 ft above mean sea level, the engine began to vibrate. About 30 seconds later, he heard a “bang.” A piece of the engine had penetrated the engine cowling, and engine oil covered the outside of the canopy, restricting the pilot's vision. He stated that the engine lost total power and that an extreme vibration occurred until he slowed the airplane and the propeller stopped rotating. The pilot chose to fly to an airport that he identified on his GPS and performed a forced landing at that airport, during which the left main gear separated from the fuselage after impact with a piece of debris on the runway. The airplane slid on its belly before veering off the runway and coming to rest in the grass. It was later determined the pilot had landed at an abandoned airport. An initial examination of the engine, which was a modified version of a six-cylinder Lycoming AEIO-540 engine, revealed a hole in the top of the crankcase just behind the oil filler cap at the No. 5 cylinder. The crankshaft was visible through the hole in the top of the engine, and a broken counterweight was noted. Metallurgical examination of the crankshaft revealed that it had fractured between the No. 5 and No. 6 rod journals. The fracture was the result of a fatigue crack that initiated from the aft radius of the No. 5 rod journal. The surface of the No. 5 rod journal and the radii contained circumferential gouges, which suggest that the bearing for this rod journal had shifted or was thinning down; the gouges were the stress raisers that led to the fatigue cracking. Shifting or malfunction of the bearing likely interfered with the lubrication of the rod journal surface and their radii, which likely caused the eventual overheating of the rod journal. The property that once was the airport belonged to the Texas Parks & Wildlife Department. Although the property was no longer maintained as an airport, the Texas Parks & Wildlife Department had not contacted the Federal Aviation Administration to update the status of the airport. Appropriate steps were taken to decommission the airport after this accident.
On March 25, 2018, about 1645 central daylight time, a MX Aircraft LLC, MXS airplane, N540JH, collided with an object during a forced landing on an abandoned runway. The pilot was not injured, and the airplane was substantially damaged. The airplane was registered and operated by Rob Holland Ultimate Airshows LLC under provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. Day visual meteorological conditions prevailed for the flight, which was not operating on a flight plan. The flight originated from NAS Kingsville (NQI) Kingsville, Texas, about 1620, with an intended destination of The Red River Airport (0R7), Coushatta, Louisiana. The abandoned runway was identified as the Kalt Ranch Airport (9TE5), Fulton, Texas. The pilot reported that while in cruise flight at 11,500 ft above mean seal level (msl) the engine began to vibrate. About 30 seconds later he heard a "bang." He reported the engine lost all power and there was an extreme vibration until he slowed the airplane and the propeller stopped rotating. A piece of the engine penetrated the engine cowling and engine oil covered the outside of the canopy restricting the pilot's vision. The pilot located 9TE5 on his GPS and maneuvered the airplane to stay close to the airport. The pilot first saw the runway at an altitude of about 700 ft msl after he descended below the cloud layer at which time, he was committed to land with a 25-knot tailwind. The airplane touched down about one-third the way down the runway. The pilot did not see a large piece of debris on the runway due to the oil on the canopy. The left main landing gear separated from the fuselage, when it contacted the debris. The airplane slid on its belly before veering off the runway into the grass. The debris was identified as a piece of a building roof, that had been blown onto the airport during Hurricane Harvey. The engine was a modified version of a six-cylinder Lycoming AEIO-540 engine. An examination of the engine revealed a hole in the top of the crankcase just behind the oil filler cap at the No. 5 cylinder. All four engine mounts were torn from the engine and the only structure holding the engine in place was the cowling. The engine was removed and examined further. The crankshaft was visible through the hole in the top of the engine and a broken counterweight was noted. The accessory section of the engine was pulled away and angled to one side. The aft top section of the oil sump was fractured, and only residual oil remained in the sump. The left magneto had separated from the engine. The oil screen and oil pump were clear of debris. The crankshaft gear was damaged, and all other accessory gears were undamaged. The top cylinders exhibited normal combustion signatures. It was noted that the crankshaft was broken, and one counterweight was missing. The broken crankshaft was removed from the engine and sent to the National Transportation Safety Board (NTSB) Metallurgical Laboratory for examination. The examination revealed the crankshaft fractured between the No. 5 and No. 6 rod journals. The forward fracture surface contained crack arrest marks indicative of fatigue cracking that emanated from the aft radius of the No. 5 rod journal. The fatigue crack propagation was through about 90% of the cheek cross section. The remaining fracture exhibited features consistent with overstress separation. The surface of the No. 5 rod journal and both radii for this journal exhibited black-blue heat tint consistent with exposure to heat and contained circumferential gouges. All the lubrication ports were free of debris. A connecting rod which was fractured at the arm, remained attached to the No. 6 rod journal. The arm portion in the area of the fracture showed evidence of elongation deformation. One of the two counterweight assemblies fractured from the cheek. An ear portion extends out of the cheek and it serves as an attachment point for the counterweight assembly. The counterweight separated at the ear portion. The fracture surfaces on the connecting rod arm and the attachment ear for the counterweight assembly exhibited signatures consistent with an overstress separation. During the investigation it was determined that the airport was abandoned and that the property, now part of the Goose Island State Park, belonged to the Texas Parks & Wildlife Department. Although the property was no longer maintained as an airport, the Texas Parks & Wildlife Department had not contacted the Federal Aviation Administration regarding the status of the airport. The Assistant Superintendent of the park was contacted by the NTSB investigator-in-charge regarding the status of the airport. The assistant supervisor promptly took the steps to have the airport decommissioned.
A total loss of engine power due to the fatigue failure of the crankshaft, which resulted in the pilot’s forced landing to an abandoned airport and the airplane’s subsequent impact with debris on the runway.
Source: NTSB Aviation Accident Database
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