LAX00FA300 · Beech K35

At 1247, during cruise flight, the pilot advised the radar controller that he had a little oil leak on his windshield. The severity of the leak increased, and 5 minutes later oil had covered the front windshield thus precluding visibility. One minute later, the pilot announced that he had "totally lost oil pressure." Prior to the engine seizing, the pilot attempted to make a forced landing on an interstate freeway. During flare, the airplane impacted three automobiles, cartwheeled, and came to rest upside down. Three days before the accident, the pilot had flown his airplane from Torrance, California, to Bullhead City, Arizona. En route, an engine oil leak became evident, which inhibited the pilot's ability to see through the front windshield. The pilot believed that engine oil was leaking past the engine's crankcase nose seal, aft of the propeller, and that replacing the seal would resolve the leakage problem. (Seepage had been documented in this crankshaft area during the last annual inspection that was completed 21 engine operational hours earlier.) The pilot flew 16 miles to near Needles, California, where repair services were available. Upon arrival, oil was dripping off the engine, and the pilot was advised by an engine shop to have the engine removed and repaired. The pilot declined indicating that he had insufficient funds. Instead, the pilot purchased the nose seal parts from the engine shop, and he hired a local independent mechanic to install them in his airplane. Upon completion of the maintenance, the mechanic requested that the pilot perform a ground run-up to check for leaks. The pilot declined and took off. The accident occurred about 40 minutes later, 92 miles from Needles. In 1986, about 537 engine operational hours earlier, the airplane's landing gear collapsed and the propeller was damaged. The crankcase was found cracked on its front, right side, and the engine was overhauled. The case was repaired, according to the maintenance records. During the last annual inspection, oil seepage was noted on the front, right side of the case. During the accident investigation, a weld was noted on the front, right side of the case, and electrical arc marks were noted about 2.3 inches inside the crankshaft bore. The crankshaft was found to have fractured, and the fracture had originated at the site of the arc marks creating a stress riser in the crankshaft. As the fracture progressed, it provided an avenue for oil to escape from the crankshaft and propagate through the nose seal.

Verbatim NTSB analysis and probable cause from the NTSB dataset