Aviation Accident Summaries

Aviation Accident Summary ERA10LA175

Hilton Head Island, SC, USA

Aircraft #1

N9JE

SMITH EDWARD I LANCAIR IV-P

Analysis

**This report was modified on 8/8/13. Please see the docket for this accident to view the original report.** The pilot stated that while in cruise flight he observed the instrument panel begin to vibrate heavily and oil begin to cover the wind screen before hearing a loud "bang." The engine then lost power as oil continued to obscure the wind screen. The pilot had no forward visibility and could not maintain the airplane's altitude. He elected to make an emergency landing on a nearby beach and during the landing the airplane struck and killed a pedestrian. Examination of the airplane revealed that the propeller assembly separated from the crankshaft and was missing. The propeller assembly and propeller flange were not recovered. An examination by the NTSB Materials Laboratory of the crankshaft revealed that the aft face of the fracture contained crack arrest marks. The fracture of the crankshaft was caused by multiple-origin fatigue cracks that emanated at the aft relief radius for the propeller flange. The records for this engine and airplane do not show an entry of a propeller strike. However, multiple-origin fatigue cracks that extend nearly 50% around the circumference of the aft relief radius for the propeller flange suggest that the propeller had struck an object prior to fracture of the crankshaft. In the absence of material anomalies, the fatigue cracking appears likely to have been caused by external impact stress, such as a propeller strike.

Factual Information

On March 15, 2010, about 1810 eastern daylight time, an experimental amateur-built Smith Lancair IV-P, N9JE, registered to and operated by a private owner, lost engine power during cruise flight near Hilton Head, South Carolina. The airplane struck a pedestrian while making a forced landing on a beach. The pilot and passenger were not injured but the pedestrian was killed. The airplane sustained minor damage. Visual meteorological conditions prevailed and an instrument flight rules (IFR) flight plan was filed for the 14 Code of Federal Regulations Part 91 personal flight from Orlando Executive Airport (ORL), Orlando, Florida, to Hampton Roads Executive Airport (PVG), Norfolk, Virginia. The pilot stated that his flight was uneventful until just past the Tybee intersection on the V1 airway heading north. He first noticed a vibration in the instrument panel followed by oil spraying on the windshield. He immediately contacted air traffic control and declared an emergency. He was advised that Hilton Head Airport (HXD), Hilton Head Island, South Carolina, was 15 miles from his location and the closest airport available. As he turned towards Hilton Head Island, the windshield became completely covered and obscured with dark brown colored oil, leaving no forward visibility. There was a violent shake of the airplane, followed by a violent "bang". The pilot stated he also heard what sounded like an engine over-speed just after the violent shaking. Shortly thereafter, engine power was lost and Jacksonville Center requested that the pilot switch to Beaufort Approach. Contact was made with Beaufort Approach, and radar vectors and headings were given to HXD. As the pilot attempted to make it to HXD, he realized that he would not have enough altitude to make it to HXD, and advised air traffic control that he was electing to make an emergency landing on the beach. The airplane's electronic flight instrument system and multi-function display went blank, and he switched to the standby instruments for airspeed and altitude readings. He approached the beach perpendicularly, and flew a modified downwind while looking out of the left window to clear a spot for landing. He stated that a gradual 180-degree turn was made before landing north on the edge of the surf. At the time of the landing, the right gear mechanism failed and the right gear collapsed. As the airplane skidded to a stop, it "skewed towards the ocean and stopped at the edge of the water." After the pilot exited the airplane, he realized that part of the airplane had struck an individual on the beach. He said that he never saw or felt the impact of the individual during the emergency landing. A witness reported that he watched as the airplane made a series of unusual turns. He did not realize that the airplane was in distress at the time, and continued to observe its movements. The airplane descended on a right base as it flew parallel to the beach. As the airplane descended, it flew directly over the witness and he noticed that the airplane had an engine-out emergency. The airplane touched down approximately 200 feet in front of the witness, in an area where there were several pedestrians. The airplane came to rest at the water's edge and a fallen pedestrian was observed lying on the beach. Examination of the airplane by a Federal Aviation Administration (FAA) inspector revealed that the airplane came to rest on a beach. The airframe was intact, and all flight control system components revealed no evidence of preimpact mechanical malfunction. Further examination of the airplane revealed that the crankshaft separated aft of the propeller attachment flange. The propeller assembly and propeller flange were not recovered. The engine was disassembled and inspected by a Teledyne Continental Motors (TCM) investigator with FAA oversight. No anomalies were noted within the engine assembly. TCM found evidence of fatigue cracking on the fracture face of the crankshaft. At the request of the NTSB Materials Laboratory, TCM made a cut through the main journal portion in an area located approximately two inches aft of the fracture. The two-inch segment was shipped to the NTSB Materials Laboratory for further examination. An examination by the NTSB Materials Laboratory of the two-inch segment of the crankshaft revealed that the aft face of the fracture contained crack arrest marks. The aft relief radius for the propeller flange contained no evidence of mechanical damage, such as gouge marks. The fatigue crack propagated through the full thickness of the wall of the crankshaft, and extended around approximately 50 percent of the crankshaft circumference. The remaining portion of the fracture face contained a rough texture consistent with overstress separation. A review of the engine logbooks dating back to September 13, 1996, revealed that the engine was installed on a Piper Malibu, N70DL, serial number 46-8608001, and did not reveal any anomalies that would have been contributing to the fatigue crack. The last entry dated July 28, 1998, at a Hobbs time of 1806.6 hours for aircraft N70DL revealed that an oil and filter change was conducted. There were no entries for this engine for the next four years. A review of the propeller and aircraft logbook entries also did not reveal any anomalies that would have contributed to the fatigue crack. On May 31, 2002, the records revealed that the engine was disassembled, cleaned, and inspected to check for corrosion and overall condition. New exhaust guides were installed; the valves and seats were ground, the cylinders were oversized and new piston rings were installed. The engine was reassembled using parts that were supplied on a work order in accordance with data approved by or acceptable to the FAA. The engine was run in a test cell and returned to service. The engine was then stored for approximately seven years. After the engine was purchased by the new owner, a logbook entry revealed that the engine was converted from a model TSIO-550-C to a model TSIO-550-B in accordance with Continental Service Bulletin M75-6, REV. 1, and dated 6/4/1975. The conversion was completed by the owner/mechanic on January 15, 2009, installed and returned to service after a 100-hour inspection. The engine accumulated 99 hours since it was converted and installed on the current airplane. In a telephone conversation with the previous owner of the engine, he said that he originally intended to install the engine in an airplane that he was building. The engine was sent to a service center to be inspected, and repaired as necessary. He had no knowledge of any damage to the engine during his ownership. The engine was never installed on his airplane or used after the service.

Probable Cause and Findings

A loss of engine power due to the failure of the crankshaft as a result of a previous propeller strike.

 

Source: NTSB Aviation Accident Database

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