Woodstock, AL, USA
N82049
Champion 7AC/BCM
The Champion 7AC/BCM aircraft was observed by numerous eyewitnesses, including some of the pilot's family members, to pass closely overhead their respective residences, and then commence a series of tight 360-degree turns at about 60 to 70 feet agl, over his mother's back yard. Following a "pop" which most witnesses characterized as an engine backfire, the aircraft was observed to dive into the ground. Examination of the wreckage site revealed severe postcrash fire damage to the cockpit and aft engine area. Although most engine accessories were partially consumed by fire, the engine manufacturer's investigator could find no cause to preclude normal engine operation, precrash. Examination of the airframe revealed no condition that would have caused a loss of control, precrash. The carburetor was examined by an FAA Repair Station and the carburetor idle metering tube diameter was found to be smaller than what the Stromberg carburetor specifications called for.
HISTORY OF FLIGHT On October 7, 2001, about 1700 central daylight time, a Champion 7AC/BCM, N82049, registered to and operated by Champion Flyers Flying Club, Inc., as a Title 14 CFR Part 91 personal flight, crashed while maneuvering in the vicinity of Woodstock, Alabama. Visual meteorological conditions prevailed and no flight plan was filed. The aircraft was destroyed by postcrash fire, and the private-rated pilot, the sole occupant, sustained fatal injuries. The flight departed Bessemer, Alabama, about 15 minutes before the accident. According to numerous eyewitnesses, including family members of the pilot, who had directed their attention skyward following a low pass over their respective rural residences, they saw the aircraft execute two or three right hand 360-degree tight turns at about 60 to 80 feet agl, over the pilot's mother's backyard. Following a noise characterized as a "pop" as in an engine backfire, the aircraft nosed over and impacted the backyard in a steep vertical attitude. Numerous witnesses had careers in or had long backgrounds in the maintenance and operation of the internal combustion engine, and were reasonably certain of the backfire report. They stated that the aircraft was not in a spin, and that the final maneuver was more like a "nose dive" into the terrain. Two of the witnesses and one of the pilot/club members who occasionally flew with the accident pilot stated that the pilot never made more than one 360-degree turn over the family homes. On this particular occasion, witnesses were equally divided on observing two or three 360-degree tight turns. PERSONNEL INFORMATION The pilot held a Federal Aviation Administration (FAA), private pilot certificate for airplane single-engine, land. His most recent FAA third class medical certificate was issued on November 2, 2000, with the limitation, "must wear corrective lenses while exercising the privileges of his airman certificate." Family members at the wreckage site stated the pilot had been flying low passes over the area since he had become a member of the flying club in December, 1997. Flying club records revealed that the pilot had flown N82049 a total of 118.77 hours since his inclusion into the club on about October, 1997, until June, 2001. The pilot's personal flight log book was not recovered, but he listed his total flight time as 220 hours on his application for a medical certificate on November 2, 2000. According to one of the flying club members, the pilot had flown previously with the Civil Air Patrol, and he estimated the pilot's total flight hours to be between 300 and 400 hours, with about 150 hours in the Aeronca type aircraft. AIRCRAFT INFORMATION The aircraft was built in 1946 as an Aeronca 7AC with a Continental C-65 power plant installed. In November,1996, during an engine overhaul, it was converted to 85 hp in accordance with STC SE00979AT, and the aircraft was redesignated the 7AC/BCM. The aircraft had undergone an annual inspection and was returned to service on September 20, 2001, at a tachometer time of 1,057.89 hours. At that time the wing was inspected in compliance with FAA Airworthiness Directive No. 2000-25-02 R1 which requires a visual inspection of the entire length of the front and rear wood wing spars for cracks, bolt or nail hole cracks, or loose or missing rib nails. The aircraft was flown to a regional fly-in at Evergreen, Alabama, on October 5, and flown back to Bessemer on October 7, landing at about 1230 by one of the five flying club members. He had Bessemer Aviation top off the fuel tank with 2.5 gallons of 100 octane LL aviation fuel, and secured the aircraft in their "T" hangar. He stated that he experienced no aircraft discrepancies during the return flight that included two stops between Evergreen and Bessemer. The invoice for the fuel sale and the fuel farm contamination report is an attachment to this report. The remaining owner/pilots stated the aircraft had a habit of "backfiring" on rapid throttle movements toward full or idle power, especially toward idle power. METEOROLOGICAL INFORMATION The METAR for 1653 for Shelby County Airport, located 115 degrees magnetic, about 18 NM from the accident site recorded the winds as variable at 3 knots, visibility 10 statue miles, no cloud cover, altimeter setting of 30.23 inches Hg, and ambient temperature of 70 degrees F, with a dew point of 40 degrees F. WRECKAGE AND INFORMATION The wreckage site was located about 240 degrees/14 statute miles from the Bessemer airport near the community of Woodstock, Alabama, where four family, (pilot's relatives) rural home sites are located within a radius of about 1/2 mile. The crash occurred in the backyard of the pilot's mother's residence at coordinates, N33:10.694 degrees by W87:11.482 degrees. The longitudinal axis of the wreckage was oriented 330 degrees, magnetic in a corner of the backyard bounded by 60 to 70-foot trees at 12 o'clock and 120 feet from the wreckage and 50-foot trees at 9 o'clock and 82 feet from the wreckage. Examination of the wreckage site revealed a steep dive into the terrain that resulted in no horizontal dimension to the wreckage path. Postcrash fire consumed the entire fabric wing and fuselage covering. The aircraft impacted upright with evidence of heavy downward momentum and very little forward momentum. The wings collapsed downward, and were still attached to the steel tube fuselage, except for the left, aft spar attachment where the attaching bolt was found sheared at both ends. The wooden wing spars were substantially scorched, but remained intact, and in their respective normal locations. The wing lift struts were intact, and in their respective normal locations. The fire appeared to have emanated from the fuel tank, located just forward of the instrument panel. The cockpit area and instrument panel were totally consumed. The magneto switch and most of the turn and bank indicator survived. The magneto switch was found in the "both" position, and the turn and bank indicated a hard right bank. Four aluminum outer wing ribs of the left wing and three inner ribs of the right wing had been consumed by fire. The steel tube fuselage was bent about 70 degrees toward the right wing tip starting from a point behind the rear seat, but witnesses stated some of the deformation occurred in extricating the pilot. Fire damage to the cockpit area precluded complete confirmation of flight control path continuity, however, the control cables for the aileron, elevator, and rudder were properly attached at their individual surfaces. The elevator trim components survived the fire and appeared to be set between neutral and slightly nose down. The fixed rudder tab survived the fire and was set at about a neutral setting. The two-bladed fixed pitch metal propeller was found intact with no pieces separated, still mounted to the crankshaft flange. One blade revealed "S" bending with numerous chordwise scratches and sand burnishing. The other blade exhibited forward bending of about 15 degrees from about its midspan outward, and its surface revealed minimum chordwise markings. The propeller tip had received leading and trailing edge deformation. Dirt was densely packed between one blade and the front surface of the engine cowling. The engine rear accessory case, including the magnetos, the tachometer generator housing, the oil pump, and the oil filter were partially fire consumed, and various pieces of each were found in the dry sump following engine teardown inspection. The engine intake manifold and exhaust pipes survived the fire and were found unobstructed. The Teledyne Continental Motors C-85-8F engine, serial number 24262-7-8 was removed from the wreckage site, transported to a hangar at the Bessemer airport, and disassembly examined by a factory investigator. His report states the engine disassembly and a visual inspection of the engine and its components did not reveal any discrepancies which would have precluded normal operation prior to impact. A copy of the Teledyne Continental Motors, Department of Air Safety, Engine Disassembly Report is an attachment to this report. MEDICAL AND PATHOLOGICAL INFORMATION Postmortem examination of the pilot was conducted by Dr. John R. Glenn, M.D., Alabama State Deputy Medical Examiner, Department of Forensic Sciences, Tuscaloosa, Alabama, on October 9, 2001. The cause of death was attributed to multiple blunt force trauma secondary to pilot in single airplane crash. Postmortem toxicological examination of specimens from the pilot was conducted by the Federal Aviation Administration Research Laboratory, Oklahoma City, Oklahoma. Tests were positive for ephedrine, pseudoephedrine, and phenylpropanolamine in the urine. The compounds were not detected in the blood. Pseudoephedrine is a common decongestant with a trade name Sudafed that is found in many over-the-counter cold and allergy preparations. Ephedrine is sold as an asthma medication, (trade name Primatene) available over the counter in tablet form. Phenylpropanolamine is an over-the-counter decongestant, also marketed as a weight loss product. It is also a metabolite of ephedrine and pseudoephedrine. It has recently been withdrawn from the market due to a very small but measurable increased risk for stroke, (primarily in women using it for weight loss) associated with its use. TESTS AND RESEARCH The Stromberg carburetor, part number 380167-2 was removed from the wreckage and subjected to a disassembly examination by an FAA certified carburetor repair station, with NTSB oversight. This particular model carburetor does not have an accelerator pump installed, and the mixture control was wired full rich, per factory bulletin. All components of the carburetor appeared normal and operational, except for one item. It was determined from Stromberg carburetor specification sheets that the proper idle metering tube bore diameter should be drill size number 65. What was found was an idle metering tube hole diameter of drill size number 70, which is visibly smaller in bore. According to repair station personnel, the smaller size would exacerbate an already existing requirement for slow, steady throttle movements due to the lack of an accelerator pump. Repair station personnel stated the smaller bore could also explain the "backfire" reports of several eyewitnesses to the accident. Three components were sent to the NTSB Materials Laboratory for failure analysis. A turnbuckle that connected the right and left aileron control cables was sent for internal thread failure analysis. Most threads exhibited extreme damage from exposure to high temperatures; however, some of the threads exhibited overload fracture. The bolt shank for the left wing aft spar attachment was also sent to the laboratory for failure analysis. It exhibited shearing overstress at both ends of the bolt, as in terrain impact. A tab welded to the right front rudder pedal that attaches to the rudder cable was examined by the laboratory. It also exhibited evidence of overstress bending in one area of the fracture. The remaining area of the fracture was too badly damaged to determine failure mode. A report of the findings from the NTSB Materials Laboratory is an attachment to this report. ADDITIONAL INFORMATION The wreckage was returned to the Champion Flyers Flying Club, Inc., the owners of the aircraft, on October 8, 2001. Those components removed for examination by the NTSB Materials Laboratory were returned to the Champion Flyers Flying Club, Inc. by registered mail on March 2, 2002. The carburetor was returned to a representative of the owners on June 8, 2002.
The failure of the pilot to maintain aircraft control while maneuvering at a low altitude, resulting in an uncontrolled descent and inflight collision with the terrain.
Source: NTSB Aviation Accident Database
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