Aviation Accident Summaries

Aviation Accident Summary ERA10LA102

Dexter, KY, USA

Aircraft #1

N499CM

DAVIS MICHAEL J LONGEZ

Analysis

A witness observed the experimental, amateur built airplane perform a steep bank in an aerobatic-type maneuver. After about 30 seconds, he observed a large explosion as the airplane’s left wing separated during its collision with trees. The airplane continued its descent and impacted the ground inverted between a residential driveway and the row of trees. The airplane was consumed by the subsequent fire. A postaccident examination revealed that the engine’s single magneto P-lead terminal end had made contact with an adjacent fabric covered steel braid oil cooler hose line. Closer examination of the ignition lead disclosed that chaffing had exposed the metal strand layer of the hose. The grounding of the magneto would have rendered the engine unable to produce power due to the lack of an ignition source. The condition of the propeller blades at the wreckage was consistent with the engine not operating at the time of ground impact.

Factual Information

HISTORY OF FLIGHT On December 25, 2009, at 1455 central eastern standard time, an experimental, amateur-built, Davis Long EZ, N499CM, was destroyed by fire after impacting the ground in Dexter, Kentucky. The pilot was killed. Visual meteorological conditions prevailed and no flight plan was filed for the flight that originated at the Grayson County Airport (M20), Leitchfield, Kentucky. The personal flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. The pilot flew into M20 earlier that day to visit family members in the area and departed at about 1440, heading to Unity City, Tennessee. A witness observed the airplane flying north before noting the airplane performing a “hard bank with the right wing high.” It seemed to be doing an aerobatic maneuver. She kept the airplane in sight for about 30 seconds before she observed a large, orange, mushroom-like explosion. The witness drove toward the fire and called authorities upon reaching the airplane wreckage at a private residence. The airplane impacted trees and came to rest flat on the ground between the residence’s driveway and the east-west row of trees toward the main street. The witness described the weather, at the time of the accident, as overcast, windy, and with small snow flurries. Relatives of the pilot stated to the responding Federal Aviation Administration (FAA) that they had expressed concerns to him about the weather, but he was adamant about flying to his destination. The pilot’s brother had previously voiced concern over the accident airplane’s fuel lines, believing that the pilot may have caused stress fractures while installing them. He stated that the last time he flew with the pilot, he could smell fuel in the cockpit “at various power settings.” He was unsure whether the problem had been remedied by the time of the accident. PERSONNEL INFORMATION The pilot, age 52, held a private pilot certificate, with ratings for airplane single engine land. He was issued a FAA third-class medical certificate on June 11, 2009, with a limitation that must wear corrective lenses. The pilot documented a total of 925 flight hours in all aircraft at the time of the medical. He also held a repairman experimental aircraft builder certificate, with a limitation inspection certificate for experimental aircraft make MD special, model EZ, serial number 001, issued December 28, 1996. AIRCRAFT INFORMATION The composite construction, 2 place tandem, Michael J. Davis LongEZ was issued a special airworthiness certificate in the experimental class under the amateur-built category on June 29, 2009. A review of the airplane's maintenance records, that were provided, revealed that the airplane’s last inspection was performed on June 27, 2009, at a total airframe time of 3.4 hours. The rear mounted engine was a Lycoming O-320-E2D, equipped with a single ignition system, with a total time in service of 1,800 hours at time of installation. The last maintenance was performed on August 26, 2009, at a total airframe time of 38.0 hours. Examination of the provided maintenance records revealed no unresolved maintenance discrepancies against the airplane prior to departure. METEOROLOGICAL INFORMATION The nearest official weather reporting station was the Campbell Army Airfield, Hopkinsville, Kentucky, located approximately 40 miles east of the accident location. The 1455 surface observation was: winds 220 degrees at 15 knots; visibility 10 statute miles; overcast clouds at 2,400 feet; temperature 0 degrees Celsius (C); dew point -5 degrees C; altimeter 29.78 inches of mercury. WRECKAGE AND IMPACT Examination of the accident site showed the airplane’s initial contact was near the top of a row of 30 foot tall trees, which separated a section of the left wing. The section of left wing came to rest several feet from the tree on a driveway; partially intact. The remaining airplane structure impacted the ground upside-down, flat, about 50 feet from the initial tree contact point. A post crash fire consumed the main wreckage. The wreckage energy path was toward the east. Wreckage debris and navigational charts were scattered near the main wreckage and in the surrounding trees. Several larger tree branches were found within the main wreckage. The only distinguishable airplane components in the burnt wreckage were the engine and several metal components. One of the two composite propeller blades remained intact on the propeller flange with thermo damage. The other blade was consumed by fire. There were no propeller slash marks at the site. A post wreckage recovery engine examination established engine drive train continuity. The #2 and #4 cylinders did not hold compression, and the #1 cylinder bottom plug produced a weak spark. The oil screen and carburetor fuel filter were both clean, and the fuel line micro filter had no significant debris. The examination revealed that the single magneto’s P-lead terminal end had a section worn and had been making contact with the fabric covered steel braid oil cooler hose line, to which the chafing exposed the metal layer of the hose. MEDICAL AND PATHOLOGICAL INFORMATION The Office of the Chief Medical Examiner, University of Louisville, Division of Forensic Pathology, Louisville, Kentucky, conducted a postmortem examination of the pilot. The cause of death was smoke inhalation and perimortem thermal injuries. Postmortem toxicology tests were performed by the FAA Forensic Toxicology Laboratory, Oklahoma City, Oklahoma, on specimens obtained from the pilot. The tests were negative for ethanol and drugs, and positive for carbon monoxide and cyanide.

Probable Cause and Findings

The loss of engine power due to the chaffing and grounding of the single magneto's ignition lead.

 

Source: NTSB Aviation Accident Database

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