Aviation Accident Summaries

Aviation Accident Summary MIA02GA137

Tyner, NC, USA

Aircraft #1

N928CP

Cessna 172S

Analysis

The flight departed about 1300 with a pilot, co-pilot, and observer (law enforcement officer) on-board for a marijuana eradication flight operated by the Civil Air Patrol. The airplane had been operated earlier that day in the morning and afternoon orbiting throughout areas of the county between witness reported altitudes of between 300 and 500 feet agl on the same type of mission by the same pilot. After departure on the accident flight, the flight continued the aerial observation and according to one witness, on the last pass, the airplane was observed in a large clockwise orbit noticeably lower than the 300 to 500 feet agl previously observed. A sputtering noise was heard by one witness, and another stated there was no engine sound at all just before she observed the aircraft depart normal upright flight. From an altitude of about 120 to 150 feet agl, she saw the aircraft simultaneously nose over vertically and commence a right half roll into the terrain. The airplane came to rest inverted in a field containing cotton crops. One EMT who was on-scene within minutes of the accident reported observing a finger sized stream of fuel leaking from the left wing root area; the leakage lasted an estimated 15-20 minutes. Other personnel on scene stated they did not smell a strong odor of fuel after arriving within minutes of the crash. There was no evidence of leakage from the right fuel tank; the header tank was impact damaged. The fuel selector was found positioned to the "both" position. No evidence of preimpact failure or malfunction of the flight controls for roll, pitch, and yaw was noted, and no evidence of preimpact mechanical failure/malfunction of the engine, magnetos, or mechanical fuel pump was noted. The flaps were extended 10 degrees. Bench testing of the impact damaged fuel injection servo as received revealed it flowed greater than specified service limits. The impact damaged mixture control shaft was replaced, the unit was flow tested and found to flow within limits at all ranges above idle. Examination of the flow divider revealed the cover had the same safety wire pattern as the pattern used during manufacturing; bench testing of the unit revealed it operated at 2.0 psi; no contamination was noted following disassembly, and the spring was not failed. Fuel consumption calculations indicate that an estimated 15 gallons of fuel should have been on-board at the time of the accident.

Factual Information

HISTORY OF FLIGHT On July 17, 2002, about 1522 eastern daylight time, a Cessna 172S, N928CP, registered to the Civil Air Patrol, Inc., crashed while maneuvering in the vicinity of Tyner, North Carolina. Visual meteorological conditions prevailed and no flight plan was filed for the local, public-use, counter-drug mission flight, from the Northeastern Regional Airport, Edenton, North Carolina. The aircraft was destroyed and a private-rated pilot, a commercially-rated copilot, and an observer received fatal injuries. The aircraft departed Northeastern Regional Airport, Edenton, North Carolina, at about 1300. According to the personnel from the Chowan County Sheriff's Department and the Civil Air Patrol, the aircraft was being utilized in marijuana crop spotting. Another Civil Air Patrol aircraft was conducting the same mission in adjacent areas of the county. Witnesses observed both aircraft maneuvering in different areas throughout the county during the morning and afternoon at altitudes of about 300 to 500 feet above ground level (agl), with occasional maneuvering at lower altitudes. On the pass that N928CP crashed, witnesses stated the aircraft was in a large clockwise orbit, and was noticeably lower than 300 to 500 feet agl. A sputtering noise was heard by one witness, and another stated there was no engine sound at all just before she observed the aircraft depart normal upright flight. From an altitude of about 120 to 150 feet agl, she saw the aircraft simultaneously nose over vertically and commence a right half roll into the terrain. PERSONNEL INFORMATION The pilot-in-command and left seat occupant, age 38, was the holder of a private-pilot certificate with airplane single engine land, and instrument airplane ratings. He was issued a Federal Aviation Administration (FAA) second-class medical certificate on October 24, 2000, with no limitations. He was a First Lieutenant in the Civil Air Patrol's, (CAP) North Carolina Unit 137. A review of his pilot logbook revealed his last biennial flight review required by 14 FAR 61.56 occurred on May 15, 2001. He logged a total time of approximately 577 hours, of which 294 were in the accident make and model airplane. Of the 577 total time logged, 552 hours were as pilot-in-command. His logbook reflected he received his first CAP pilot checkout in March 1997. He had completed the CAP Cannabis Detection Course in May 1997, in the Cessna 172 type aircraft. CAP records revealed his most recent CAP flight check occurred on February 22, 2002; and was flown in a Cessna 182R airplane. The second-in-command and right seat occupant, age 46, was a Captain in the CAP's North Carolina Unit 153, and was the holder of a commercial pilot certificate with airplane single engine land, rotorcraft helicopter, and instrument airplane ratings. His was issued a FAA second class medical certificate on October 7, 2001, with no imitations. Examination of CAP flight records for the pilot showed his most recent biennial flight review required by 14 FAR 61.56 occurred on February 8, 2002. The observer, seated in the rear seat was not a licensed pilot and was on his first drug spotting mission which he volunteered for. He was a deputy with the Chowan County Sheriff's office. AIRCRAFT INFORMATION The airplane was manufactured in 2001, as a Cessna model 172S, serial number 172S8916, and was certificated in the normal and utility categories. At the time of manufacture, the airplane was equipped with a Textron Lycoming IO-360-L2A, 180-horsepower engine, and a McCauley 1A170E/JHA7660 fixed pitch propeller. The airplane was last inspected on May 31, 2002, in accordance with an annual inspection, at a recorded tachometer time and aircraft total time of 299.1 hours. The airplane had accumulated approximately 74 hours since the inspection at the time of the accident. METEOROLOGICAL INFORMATION A METAR weather observation taken from the Elizabeth City Coast Guard Air Station/Regional Airport at 1454 hours (approximately 28 minutes before the accident) indicates the wind was variable at 3 knots, the visibility was 10 statute miles, clear skies existed, the temperature and dew point were 33 and 18 degrees Celsius, respectively, and the altimeter setting was 30.03 inHg. The accident site was located 24.7 nautical miles and 280 degrees from the airport. WRECKAGE AND IMPACT INFORMATION The airplane crashed into a cotton field during daylight hours behind a residence located at 644 Happy Home Road. The accident site was located at 36 degrees 15.390 minutes North latitude and 076 degrees 37.040 minutes West longitude, or about 16.0 nautical miles north of the departure airport. Examination of the accident site revealed the airplane came to rest inverted on an easterly heading; all components necessary to sustain flight remained attached to the airplane. A ground scar measuring 23 feet in length with red colored lens was located just forward of the left wing nearly perpendicular to the longitudinal axis of the airplane. Another ground scar was located near the engine which remained attached to the airframe. The engine, engine mount, and engine cowling were crushed rearward. Chordwise crushing was noted to the leading edges of both wings; the left wing was partly detached at the wing root and was displaced aft. The right wing was also displaced aft; the inboard corner of the right wing flap penetrated the fuselage. The only damage to the empennage was slight impact bending of the tip of the vertical stabilizer. No evidence of preimpact failure or malfunction was noted to the flight control system for roll, pitch, or yaw. The flap selector and actuator were found positioned and extended 10 degrees, respectively. The right cockpit door was separated but found in close proximity to the main wreckage. The elevator trim tab was found positioned 10 degrees trailing edge tab up. Examination of the fuel system revealed the right fuel tank was not compromised, while the left fuel tank and the header tank were compromised. No fuel was noted in the fuel gascolator, while 1/2 teaspoon of fuel was noted in the inlet area of the fuel injection servo. Examination of the engine revealed the throttle and mixture controls at the partially separated fuel injection servo were full open and full rich, respectively. Examination of the cockpit revealed the fuel selector was positioned to the "both" position. The auxiliary fuel pump switch was in the "off" position; impact damage to the switch assembly was noted. The fuel flow gauge was indicating 8.0 gallons-per-hour. The throttle and mixture controls were "full-in." Examination of the engine revealed crankshaft, camshaft, and valve train continuity. Suction and compression was noted in all cylinders with rotation of the crankshaft. The right magneto which remained securely attached to the accessory case was noted to produce spark at all ignition leads with hand rotation of the crankshaft. Impact damage to the flange of the left magneto was noted; rotation of the magneto drive shaft by hand was noted to produce spark at all ignition towers. The oil suction and fuel injector screens were clean. The engine-driven fuel pump mount arm and flange were broken; a trace amount of 100 low-lead fuel was found in the flow valve chambers of the pump. Examination of the fixed pitch propeller revealed both blades were bent aft to varying degrees and both exhibited chordwise scratches on the cambered side of the blade. Also, both exhibited minor nicks on the leading edges. MEDICAL AND PATHOLOGICAL INFORMATION Postmortem examinations of the pilot, copilot, and rear seat occupant were performed by the Chapel Hill, North Carolina, medical examiner's office. The cause of death for all was related to blunt force injuries. Toxicological analysis of specimens of the pilot and copilot were performed by the FAA Toxicology and Accident Research Laboratory, located in Oklahoma City, Oklahoma. The results of analysis of specimens of both were negative for carbon monoxide, cyanide, ethanol, and tested drugs. TEST AND RESEARCH Examination and bench testing of the fuel injection servo (servo), fuel injector nozzles, fuel injector lines, and flow divider was performed with NTSB oversight at a FAA certified repair station. Examination of the servo revealed it had impact damage and the mixture control shaft and the throttle control lever were bent to varying degrees, and the throttle stop bushing was missing. Additionally, the idle adjustment screw was found backed out. Bench testing of the servo as received revealed the fuel flow in terms of pounds-per-hour was greater than the specified service limits; however, fuel flow was noted from idle to full throttle. The impact damaged mixture control shaft was removed and replaced, and a replacement throttle stop bushing was installed. With the throttle positioned to the idle position and the replacement throttle stop bushing installed, the throttle valve was contacting servo bore (.006 inch clearance required). The servo was then bench tested which revealed no discrepancies related to fuel flow at any position above the idle position. Visual examination of the flow divider revealed the manufacturer's part number "2576556-1", and serial number "0248722", were vibro peened onto the unit. The engine manufacturer's assembly number "63B22997-Assy" was also vibro peened onto the unit. The cover was safety wired with no lead seal noted. Bench testing of the flow divider revealed the unit opened at 2.0 psi, and was noted to operate normally. Disassembly of the flow divider after testing revealed no evidence of contamination; the spring was not failed and the measured free length of the spring was less than .750 inch. Bench testing of all four fuel injector nozzles revealed a correct spray pattern. No obstructions of the fuel injector lines were noted. Review of the airplane maintenance records revealed no evidence that the flow divider had been removed, replaced, or overhauled. Further, there were no recorded engine related discrepancies on the "Aircraft Discrepancy Report" sheet for the accident airplane. The sheet contained 7 entries, with the first recorded date of November 13, 2001, and the last recorded date of May 5, 2002. According to a representative of the manufacturer of the flow divider (Precision Airmotive Corporation), it was manufactured with a 2.0 pound spring as required by the flow divider part number 2576556-1. The spring installed in the accident flow divider at the time of the accident was a 2.0 pound spring based on the measured free length. Additionally, the safety wire pattern on the cover was consistent with that of the pattern used during manufacturing. The representative of the manufacturer of the flow divider further reported that a lead seal is not used during safety wiring of the cover. At the time of manufacture of the accident engine, the required flow divider was Lycoming assembly number "63B22997", which equates to a Precision Airmotive Corporation part number "2576556-1." One emergency medical technician who was on the scene within minutes of the crash, reported a stream of fuel the size of a finger leaking from the left wing root area; the stream of fuel was noted to last an estimated 15-20 minutes. Most other responders stated they smelled no strong smell of fuel within minutes of arriving at the wreckage. Additionally, the Civil Air Patrol party to the investigation member stated he visited the scene after the investigative team had departed and reported seeing chemically burned crop. He also reported digging into the soil in the area where the airplane had come to rest and smelling the odor of fuel in the dirt he extracted. Fuel consumptions calculations indicate that based on witness accounts pertaining to takeoff and landing times, fueling information, and the number of flights performed, the airplane was estimated to have approximately 15.3 gallons of fuel on-board at the time of the accident. ADDITIONAL INFORMATION The airplane minus the retained fuel injection servo, fuel injector nozzles, fuel injector lines, flow divider, laminated passenger briefing card, Civil Air Patrol (CAP) checklist, Cessna laminated "Pilot's Checklist", and Jeppesen Low altitude IFR chart was released to Gary K. Woodsmall of the Civil Air Patrol on July 19, 2002. The retained components were released to Gary K. Woodsmall, on August 20, 2004.

Probable Cause and Findings

The loss of power for undetermined reasons, and the pilot's failure to maintain airspeed.

 

Source: NTSB Aviation Accident Database

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