Aviation Accident Summaries

Aviation Accident Summary ATL94FA023

GADSDEN, AL, USA

Aircraft #1

N7702U

CESSNA 172

Analysis

THE PILOT WAS POSITIONING THE AIRPLANE IN ORDER TO HAVE AN ANNUAL INSPECTION DONE. NO RECORD WAS FOUND OF A WEATHER BRIEFING FOR THE FLIGHT. AT THE TIME OF DEPARTURE, THE WEATHER REPORTING FACILITY NEAREST THE DESTINATION INDICATED THAT THE CEILING WAS 500 FEET. MOUNTAINOUS TERRAIN INTERVENED BETWEEN THE DEPARTURE AIRPORT AND THE DESTINATION. THE PILOT'S LOG INDICATED THAT HE HAD PREVIOUSLY FLOWN TO THE DESTINATION. THE ACCIDENT SITE WAS LOCATED ADJACENT TO AN INTERSTATE HIGHWAY THAT RAN THROUGH A VALLEY BETWEEN TWO RIDGES. THE DIRECTION OF THE WRECKAGE TRAIL SUGGESTED THAT THE PILOT AND REVERSED COURSE, SINCE THE FLIGHT PATH LED AWAY FROM THE DESTINATION. DAMAGE TO THE AIRPLANE DEMONSTRATED THAT IT HAD COLLIDED WITH ELECTRICAL TRANSMISSION WIRES, TREES, AND THE GROUND. LOCAL WITNESSES CONFIRMED THAT THE TOP OF THE IMPACTED RIDGE WAS SHROUDED IN CLOUDS.

Factual Information

HISTORY OF FLIGHT On November 26, 1993, about 1235 central standard time a Cessna 172, N7702U, collided with power lines, during cruise flight, and the ground near Gadsden, Alabama. The airplane was operated by the pilot under visual flight rules, and 14 CFR Part 91. Instrument meteorological conditions prevailed. A flight plan was not filed for the personal flight. The private pilot, who was the sole occupant, was fatally injured. He did not possess an instrument rating. The airplane was substantially damaged. Origination of the flight was Birmingham, Alabama, about 1056 on the same day. According to communication transcripts, the pilot contacted Birmingham clearance delivery at 1045 for departure clearance. He stated that he had received the Airport Terminal Information Service transmission. His destination was Albertville, Alabama, and he said that he intended to operate at 2,500 feet. The transcript indicated that the transponder was operating and that the pilot verified the airplane's altitude observed by the radar controller. Radar service was terminated at 1103 when the controller informed the pilot to resume his own navigation. The pilot stated to the controller "...it's really bumpy." Utility company employees discovered the wreckage of N7702U while searching for the cause of an electrical power outage. Three electrical transmission cables were found broken, with airplane debris in the power line right of way beneath the break. The wreckage trail led to the airplane. The wreckage was located on a steeply sloped, wooded, and rocky hillside, about 1/4 mile east of Interstate 59, and about one mile north of the Reece City exit. PERSONNEL INFORMATION The pilot's logbooks contained entries that indicated he was issued a private pilot certificate, initially, in 1940. Three pilot logbooks were provided by the pilot's family. One was labeled log book number 2. The beginning entry for log book number 2 was dated November 4, 1974. It was a flight instructor's entry stating that the pilot was qualified for the private pilot rating. Two hundred fifty flight hours were carried over from log book number 1, along with nine actual instrument flight hours and 2.2 hooded flight hours. The three log books indicated that the pilot had 2,358 total flight hours, most of which were obtained in N7702U. His log books reflected a total of 242 flight hours at night, 14 actual instrument flight hours, and 9 simulated instrument flight hours. An entry dated September 7, 1993, listed 1.3 actual instrument flight hours, with the remark "flew around weather." The pilot's last biennial flight review was dated October 7, 1991, and reflected 1.2 total flight hours, with 0.3 simulated instrument flight hours. The last entry in the pilot's log book was dated November 19,. 1993, and reflected a flight to "P.C." with remarks of "top off: tires aired up." The pilot's wife said his last flight prior to the accident flight, on the 19th, was to Pell City, Alabama, and return. A Gadsden, Alabama, police officer reported that the pilot's wife stated that he had a history of diabetes. AIRCRAFT INFORMATION The Certificate of Aircraft Registration for N7702U listed the date of issue as July 3, 1974, and the registered owner as the pilot. An entry in the pilot's log book, dated October 29, 1992, indicated that the airplane was flown to Albertville for an annual inspection. According to the pilot's log, it was picked up following the inspection on November 14, 1992. The aircraft log indicated that the last annual inspection was conducted on November 9, 1992, at a tachometer time of 1154.8 and a total airframe time of 4672.11 hours. At the accident site the tachometer hour meter indicated 1201.5 hours. The airplane was equipped for instrument flight. A listing of aircraft discrepancies was not located, nor were there any discrepancies contained in the aircraft log. METEOROLOGICAL INFORMATION A Notice to Airmen was extant on the day of the accident that the Gadsden Automated Weather Observing System was out of service. At 1055, on November 26, 1993, the hourly surface observation at Anniston, Alabama, located about 30 miles south of the accident site, was as follows: record special, sky estimated 500 feet overcast; visibility one mile in light rain and fog; temperature/dew point 53/51 degrees F.; wind 060 degrees at 6 knots; altimeter setting 30.16 In. Hg.; remarks, drizzle and rain ended at 50 minutes past the previous hour; total sky coverage/total opaque sky 10/10. The surface observation at Anniston at 1248 was as follows: surface analysis, sky estimated 500 feet broken, 1500 feet overcast; visibility 4 miles in fog; temperature/dew point 54/52 degrees F.; wind 060 degrees at 5 knots; altimeter setting 30.11 In. Hg.; total sky coverage/total opaque sky 10/10. Local residents informed police officers at the accident site that the hill where the wreckage was found was covered in clouds about the time of the local electrical power outage. WRECKAGE AND IMPACT INFORMATION Wreckage debris, blue colored fiberglass fragments that matched the airplane color, were located beneath electrical transmission wires. Police officers at the scene stated that three of the electrical wires had been broken. The wreckage trail proceeded from the wires along a magnetic heading of 250 degrees for 270 feet, and led to the main wreckage. The main wreckage consisted of the propeller, engine, fuselage, all of the left wing, and most of the right wing. Separated pieces of the right wing, and windscreen fragments, were located on the ground between the wires and the main wreckage. "U" shaped indentations and tree bark transfers were noted on the leading edge of the right wing sections. Damaged trees were also noted along the wreckage trail. The airplane was found inverted. An impact depression was located near the nose of the airplane, about ten feet uphill. The shape of the depression resembled the shape and length of the nose and left wing of the airplane. The nose gear shimmy dampener internal piston was located in the depression. The propeller was attached to the engine and was characterized by spanwise twisting of the blades toward a low pitch position. Nicks were seen in the leading edge of the propeller blades. One blade exhibited leading edge damage consistent with contact with a wound cable. The opposing propeller blade had damage on its face that was consistent with electrical arcing. The nose of the airplane was crushed aft with concurrent aftward displacement of the engine into the firewall. The nose landing gear was broken off of the fuselage. Damage was observed to the front side of the nose gear piston that was consistent with electrical arcing. There was longitudinal compression of the tail cone just behind the cabin. Both main landing gear, the vertical stabilizer, and the rudder were undamaged. The left horizontal stabilizer was bent, tip up, about its mid span point. There was chordwise crushing of the right elevator, from trailing edge to leading edge. Damage to the left wing, between the root and the landing light cutout, consisted of a downward flattening of the leading edge. The wing was broken halfway between the root and the wing strut attach point, so that the wing and the wing strut appeared to have been displaced inboard (see photograph 3). The outboard panel of the right wing was separated from the airplane. As noted above, separated sections of the right wing were found along the wreckage trail. Damage to the right wing included leading edge chordwise compression from root to tip. The right wing spar was broken at the root. The cockpit carburetor heat control was found in the "on" position, and the engine intake air box valve was positioned for heated air. Both the mixture and the throttle were in the fully forward position, and the carburetor throttle valve was in the fully open position. There was continuity of the flight control cables from the cockpit to all control surfaces, except for the right aileron which was separated from the wing. The cockpit flap handle was raised to the first notch and the flaps were deployed about 10 degrees. The pilot's seat was attached to the seat rails. A shoulder harness was not installed. The lap belt had been cut. The pilot's yoke was broken off at the instrument panel. MEDICAL AND PATHOLOGICAL INFORMATION A post mortem examination of the pilot was conducted by the Alabama Department of Forensic Sciences, 1001 South 13th Street, Birmingham, Alabama, 35205-3498. The examination report stated that the cause of death was blunt force trauma to the chest. Among the findings in the report was pancreatic fibrosis (clinical history of diabetes mellitus). A toxicological examination of the pilot was conducted by the Armed Forces Institute of Pathology, Washington, DC 20306- 6000. The report of the examination was negative for alcohol and other screened drugs. Carboxyhemoglobin saturation by carbon monoxide was listed as 3%. The report states that carboxyhemoglobin saturations of 0-3% are expected for non- smokers. TESTS AND RESEARCH The wreckage was transported to Atlanta Air Salvage, Griffin, Georgia. The engine, a Continental O-300-D, serial number 34943-D-6-D, was removed from the airframe, placed on a drum for stability, and operated using fuel from the carburetor bowl. The ignition system, intake, and exhaust systems were unchanged. ADDITIONAL INFORMATION The wreckage, aircraft records, and pilot logs were released to the pilot's wife Monnie Riddle, 801 Northcrest Drive, Birmingham, Alabama, 35235.

Probable Cause and Findings

THE PILOT'S INADEQUATE PRE-FLIGHT PREPARATION AND HIS CONTINUED VISUAL FLIGHT INTO INSTRUMENT METEOROLOGICAL CONDITIONS. FACTORS WERE FOG, LOW CEILING, AND HILLY TERRAIN.

 

Source: NTSB Aviation Accident Database

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