Aviation Accident Summaries

Aviation Accident Summary ATL93FA120

CLAYTON, AL, USA

Aircraft #1

N5473S

PIPER PA-28-140

Analysis

THE STUDENT PILOT REPORTED TO APPROACH CONTROL THAT HE WAS EXPERIENCING ENGINE PROBLEMS. THE PILOT WAS ISSUED VECTORS TO THE NEAREST AIRPORT. HIS LAST REPORTED ALTITUDE WAS 900 FT. THE WRECKAGE WAS FOUND IN A LARGE WOODED AREA APRX 5 MI FROM THE CLAYTON AIRPORT. EXAMINATION AND TEST RUN OF THE ENGINE REVEALED THAT THE ENGINE WAS RUNNING RICH. THE CARBURETOR HOUSING BOLTS WERE LOOSE AND COULD BE TURNED BY HAND. FUEL LEAKED FROM THE HOUSING DURING THE TEST RUN. THE CARBURETOR THROTTLE SHAFT AND BUSHINGS SHOWED SIGNS OF EXTENSIVE WEAR, AND WERE LOOSE IN THE HOUSING. THE FLOAT PENDULUM WAS NOT EVEN. AIRPLANE RECORDS INDICATED THAT THE CARBURETOR WAS REMOVED, INSPECTED, AND REPAIRED APRX 4 MONTHS PRIOR TO THE ACCIDENT.

Factual Information

HISTORY OF FLIGHT On July 1, 1993, about 0905 central daylight time, a Piper PA-28- 140, N5473S was substantially damaged following a collision with terrain during an emergency landing near Clayton, Alabama. The student pilot was fatally injured in the accident. The aircraft was being operated under 14 CFR Part 91 by the pilot. Visual meteorological conditions existed at the time of the accident, and no flight plan had been filed for the personal flight. The flight departed Enterprise, Alabama about 0830, and was enroute to Fayetteville, North Carolina at the time of the accident. Personnel at the Columbus, Georgia, Air Traffic Control Tower (ATC) stated that the pilot was in radio communication with their facility prior to the accident. The personnel stated that the pilot advised that he was descending from 5500 feet to 3500 feet. He later reported that his altitude was 2800 feet. About 0900, the tower received a distress call from the pilot. He reported that he was having engine trouble and could not maintain altitude. The ATC personnel gave him directions toward the nearest airport. The last radio transmission received was at 0905, and the pilot reported his altitude as 900 feet. The aircraft wreckage was located in a wooded area near Clayton, Alabama. PERSONNEL INFORMATION The pilot held a student pilot certificate. He was enrolled in the United States Army Aviation School, and had completed all of the flight training for the helicopter pilot program. He was awaiting the graduation ceremony to receive his United States Army Aviator Wings. Additional pilot information may be obtained on Page 3 of this report. AIRCRAFT INFORMATION Aircraft maintenance records showed that the last Annual Inspection was completed February 8, 1993. An invoice, provided by the aircraft owner, showed that the carburetor was removed, disassembled, inspected, reassembled, and reinstalled in the aircraft on March 2, 1993. No record of this maintenance was recorded in the aircraft, nor engine log books. Additional aircraft information may be obtained on Page 2 of this report. METEOROLOGICAL INFORMATION Meteorological information may be obtained on Page 4 of this report. WRECKAGE AND IMPACT INFORMATION The aircraft wreckage was located in a wooded area. The wreckage was distributed over an area approximately 123 feet in length, and on a heading of approximately 195 degrees. The first indication of the wreckage path were two pine trees approximately 12 inches in diameter and 60 feet in height, which had been severed at approximately 45 feet above ground level. A section of the left outboard wing, approximately five feet in length, was located approximately 15 feet in the direction of and 30 feet to the left of the wreckage path. Tree bark was found on the leading edge of the wing section. The remainder of the left wing was located approximately 66 feet in the direction of and 10 feet to the right of the wreckage path. This section of the wing also had evidence of tree bark on the leading edge. There was chordwise crushing of the leading edge of this section of the wing. An outboard section of the right wing, approximately 5 feet in length, was located approximately 99 feet in the direction of and 5 feet to the right of the wreckage path. The leading edge of this section had a large "U" shaped indention just inboard of the wing tip faring. The main wreckage, consisting of the fuselage, empennage, and remainder of the right wing were located, in an upright position, approximately 123 feet in the direction of the wreckage path. The engine and propeller were still attached to the fuselage. There was extensive deformation of the left side of the cockpit area. There was continuity of the aircraft flight controls from the rudder and elevator. A test run of the aircraft engine was conducted after removing the aircraft from the wooded area. Prior to the test run, the spark plugs were removed and inspected. The spark plugs showed signs of sooting. The engine operated to 2550 revolutions per minute (RPM). The engine ran roughly at full rich mixture settings, but smoothed out and ran to full RPM after reducing the mixture control to approximately half. Inspection revealed that the carburetor housing bolts were loose, and could be rotated by hand. There was fuel leaking from the carburetor housing during the test run of the engine. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed by Dr. Allan D. Stillwell of the Alabama Department of Forensic Sciences on July 2, 1993. The toxicological report was negative for the presence of ethanol and drugs. TESTS AND RESEARCH On January 25, 1994, an inspection of the aircraft carburetor, Marvel Schebler Model Number MA-45SPA, Part Number 10-5009, Serial Number BL 9 4397 was conducted. The inspection revealed that the carburetor had not been stamped MFV indicating compliance with an airworthiness directive requiring the installation of a one piece venturi. The carburetor housing bolts were loose, and could be turned by hand. The throttle shaft and bushings had excessive wear, and were loose in the housing. The carburetor still had the two piece venturi installed. The float pendulum was not even, with the right side resting lower than the left. ADDITIONAL INFORMATION The aircraft wreckage was released to Mr. Donald R. Andersen, attorney for the owner on March 17, 1994.

Probable Cause and Findings

INADEQUATE MAINTENANCE AND INSPECTION OF THE CARBURETOR BY MAINTENANCE PERSONNEL.

 

Source: NTSB Aviation Accident Database

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