Accident Sequence
On March 25, 2018, about 1645 central daylight time, an MX Aircraft LLC MXS airplane, registration N540JH, collided with debris during a forced landing on an abandoned runway. The pilot was not injured, and the airplane was substantially damaged. The aircraft was registered and operated by Rob Holland Ultimate Airshows LLC under 14 CFR Part 91 as a personal flight. Day visual meteorological conditions prevailed, and the flight was not 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 Kalt Ranch Airport (9TE5), Fulton, Texas.
According to the pilot, while cruising at 11,500 ft above mean sea level, the engine began to vibrate. About 30 seconds later, he heard a "bang." The engine lost all power, and extreme vibration continued until the pilot slowed the airplane and the propeller stopped rotating. A piece of the engine penetrated the cowling, and engine oil covered the outside of the canopy, restricting the pilot's vision.
The pilot located 9TE5 on his GPS and maneuvered to stay close to the airport. He first saw the runway at about 700 ft msl after descending below the cloud layer, at which point he was committed to land with a 25-knot tailwind. The airplane touched down about one-third of the way down the runway. Due to oil on the canopy, the pilot did not see a large piece of debris on the runway. When the left main landing gear contacted the debris, it separated from the fuselage. 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.
Engine Examination
The engine was a modified six-cylinder Lycoming AEIO-540. Examination 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 only the cowling held the engine in place. The engine was removed for further examination. The crankshaft was visible through the hole, and a broken counterweight was noted. The accessory section was pulled away and angled. The aft top section of the oil sump was fractured, with only residual oil remaining. The left magneto had separated. The oil screen and oil pump were clear of debris. The crankshaft gear was damaged; other accessory gears were undamaged. Top cylinders showed normal combustion signatures. The crankshaft was broken, and one counterweight was missing.
Metallurgical Findings
The broken crankshaft was sent to the NTSB Metallurgical Laboratory. 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 propagated through about 90% of the cheek cross section, with the remaining fracture consistent with overstress separation. The surface of the No. 5 rod journal and both radii exhibited black-blue heat tint consistent with heat exposure and contained circumferential gouges. All lubrication ports were free of debris.
A connecting rod, fractured at the arm, remained attached to the No. 6 rod journal. The arm showed elongation deformation. One counterweight assembly fractured from the cheek at the attachment ear. Fracture surfaces on the connecting rod arm and the attachment ear exhibited overstress separation signatures.
Airport Status
Investigation revealed that Kalt Ranch Airport (9TE5) was abandoned and the property, now part of Goose Island State Park, belonged to the Texas Parks & Wildlife Department. The property was no longer maintained as an airport, but the department had not contacted the FAA regarding its status. The NTSB investigator-in-charge contacted the assistant superintendent of the park, who promptly took steps to have the airport decommissioned.