Aviation Accident Summaries

Aviation Accident Summary MIA02LA080

Sevierville, TN, USA

Aircraft #1

N10GZ

Gary L. Zeigler Monnett Moni

Analysis

Before departure the pilot was observed to change the two spark plugs, and the airplane was fueled. During the takeoff, a witness heard the engine missing. Witnesses reported that when the airplane passed the departure end of the runway, the airplane was observed to bank to the left, pitch down, and impacted the ground in a wooded area. A postcrash fire was extinguished by a fire department. The crash site was located .10 nautical mile and 242 degrees from the departure end of the runway used for takeoff. Examination of the flight controls revealed no evidence of preimpact failure or malfunction. Examination of the engine by the FAA-IIC revealed that, "...both plugs were barely finger tight. I did not need a wrench to remove one of the plugs." No other discrepancies related to the engine were noted. The pilot's flight time in the airplane was not determined. Additionally, there were no maintenance records for the airplane.

Factual Information

HISTORY OF FLIGHT On April 6, 2002, about 0950 eastern standard time, a homebuilt Monnett Moni, N10GZ, registered to a private individual, crashed in a wooded area approximately 1/2 nautical mile west of the Gatlinburg-Pigeon Forge Airport, Sevierville, Tennessee, shortly after takeoff. Visual meteorological conditions prevailed at the time and no flight plan was filed for the 14 CFR Part 91 personal flight. The airplane was substantially damaged and the private-rated pilot, the sole occupant, was fatally injured. The flight originated about 1 minute earlier. Before the flight departed the pilot was observed to change the two spark plugs and reported to an individual that he wasn't feeling well. A witness reported that when the airplane was taking off, "his [engine] was missing." Another witness who was watching the airplane takeoff reported it appeared to him that the airplane wasn't gaining any altitude. When the airplane was at the departure end of the runway, it appeared that the pilot was attempting to "turn around." Still another witness reported seeing the airplane, "began to bank to the left almost as if the plane had stalled. The plane made a very sharp turn and headed straight down." (See witness statements.) A student pilot who was at the Gatlinburg-Pigeon Forge Airport for a solo cross-country flight reported that while performing an engine run-up, he observed the accident airplane taxi into position behind his airplane. He (student pilot) completed his run-up and taxied his airplane to the approach end of runway 28 to have all available runway for takeoff. While he was at the approach end of the runway, the accident pilot taxied onto the runway ahead of him and began to takeoff from runway 28. He began his takeoff roll when the accident airplane was approximately 75 feet above ground level (agl) on the upwind leg, and he observed the accident airplane turning crosswind. When the accident airplane was more than 1/2 way into the crosswind turn, the airplane was observed to bank "sharp" to the left. The airplane was then observed by the student pilot to pitch nose down and impacted the ground. Another witness on the airport reported seeing the airplane depart and last recalled seeing the airplane at 20 feet agl; he reported he did not hear any engine malfunction at that time (see NTSB Record of Conversation with the individual). A postcrash fire was extinguished using water by the Sevierville Fire Department. PERSONNEL INFORMATION The pilot held a FAA issued private pilot certificate with airplane single engine land rating that was issued on March 29, 1992. The pilot was issued a FAA third class medical certificate on April 25, 2001, with the restriction, "must wear corrective lenses." On the application for his medical certificate he listed a total flight time of 408 hours. The pilot's wife reported her husband did not log his flight time in the accident airplane in his pilot logbook, and she was not aware of how much flight time he had accumulated in the accident airplane. AIRCRAFT INFORMATION The airplane, a Monnett Moni, serial number 00023, was equipped with a carbureted two cylinder reciprocating engine that had one spark plug per cylinder. The designed gross weight of the airplane was 500 pounds; it was designed to be equipped with a fuel capacity of 4 gallons. An experimental airworthiness certificate for the airplane was issued by the FAA on May 30, 1984. The pilot's wife reported that her husband purchased the airplane in the summer of 2001; and there were no maintenance records for the airplane. She also stated that her husband modified the airplane to either increase the fuel capacity an additional 4 gallons, or 8 gallons, she couldn't recall which. METEOROLOGICAL INFORMATION An Automated Weather Observing System (AWOS) weather observation taken at the departure airport on the day of the accident at 0940 hours (approximately 10 minutes before the accident), indicates that clear sky conditions existed. The temperature and dewpoint were 51 and 26 degrees Fahrenheit respectively, the wind was calm, and the altimeter setting was 30.34 inHg. WRECKAGE AND IMPACT INFORMATION The NTSB did not travel to the accident site which was located at 35 degrees 51.493 minutes North latitude and 083 degrees 32.375 minutes West longitude. That location when plotted was located approximately .10 nautical mile from the departure end of runway 28. Examination of the accident site by the FAA inspector-in-charge (FAA-IIC) revealed that the crash site was located in a wooded area; a post crash fire was noted. The damage to trees indicates a vertical descent. The FAA-IIC reported that the entire fuselage was consumed by fire; the wings and tail section were "...intact and functional." Examination of the flight controls revealed all control rods that he observed exhibited overstress failure. The only flight instrument he located was the airspeed indicator which was indicating 151 miles-per-hour. Examination of the engine by the FAA-IIC revealed it did not sustain any postcrash fire. The FAA-IIC also reported that he confirmed engine valve train continuity and found that the two spark plugs looked new and were, "...barely finger tight. I did not need a wrench to remove one of the plugs." Both propeller blades of the wooded propeller were broken off at the hub. MEDICAL AND PATHOLOGICAL INFORMATION A postmortem examination of the pilot was performed by C. Blake, Forensic Pathologist. The immediate cause of death was listed as massive crash impact injuries. Toxicological analysis of specimens of the pilot was performed by the FAA Toxicology and Accident Research Laboratory (CAMI). The results of analysis by CAMI was negative for carbon monoxide, cyanide, volatiles, and tested drugs. TESTS AND RESEARCH The airplane was fueled before departure, a total of 3.8 gallons of fuel were added to the airplane. According to the FAA-IIC who obtained a sample of fuel postaccident from the source that fueled the airplane, visually no contaminants were noted.

Probable Cause and Findings

The failure of the pilot to maintain airspeed while turning to reverse direction resulting in an inadvertent stall, uncontrolled descent, and in-flight collision with trees. A factor in the accident was the failure of the pilot to tighten the spark plugs resulting in the partial loss of engine power.

 

Source: NTSB Aviation Accident Database

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