Aviation Accident Summaries

Aviation Accident Summary FTW97LA091

MIDLAND, TX, USA

Aircraft #1

N4723D

Cessna 182A

Analysis

The airplane lost engine power while on final approach for landing, and the pilot performed a forced landing to a unsuitable field which resulted in the airplane coming to rest in the inverted position. The pilot was performing a parachute jumping flight to an altitude of 12,500 feet MSL. During the descent the pilot used carburetor heat, but did not 'clear' the airplane's engine at regular intervals. The pilot reported that at 500 feet AGL the engine lost power as if 'the mixture was pulled out to stop the engine.' A carburetor icing chart was consulted, and it was determined that the temperature and dew point that the National Weather Service reported for that time did fall within the carburetor icing range. The FAA Flight Training Handbook states in the section under 'Descents (Maximum Distance Glides)' that during 'power-off descents, the engine should be cleared periodically to prevent excessive cooling and fouling.'

Factual Information

On January 25, 1997, at 1750 central standard time, a Cessna 182A, N4723D, was substantially damaged during a forced landing following a loss of engine power near Midland, Texas. The private pilot, the sole occupant of the aircraft, was not injured. The airplane was registered to and operated by a private owner under Title 14 CFR Part 91. The flight originated from Eagles Nest Airstrip near Midland, Texas, approximately 1720. Visual meteorological conditions prevailed for the local parachute jumping flight and a flight plan was not filed. According to the pilot's written statement and in interviews with the investigator-in-charge (IIC), the pilot was performing a parachute jumping flight. The pilot reported to the IIC the he performed a "normal engine run-up, which included a carburetor heat functioning check; everything check out fine." After the parachutists deplaned at 12,500 feet MSL, the pilot began his descent to land using a power setting of 15 inches and 2200 RPM. The pilot reported that he changed his power setting at 6,000 feet to approximately 10 inches and the RPM "full forward." The pilot stated that he used carburetor heat during his descent, but did not "clear" the airplane's engine at regular intervals. He further reported that at 500 feet AGL the engine lost power as if "the mixture was pulled out to stop the engine." The pilot reported that he performed a forced landing to a field covered with 7 foot high grass and mesquite brush. The airplane slid for a short distance on its nose then nosed over and came to rest in the inverted position. The pilot reported that the fuselage was bent just behind the wings, the nose gear separated from the airplane, and the right wing strut was bent. The weather conditions, at 1856, as reported by the National Weather Service for a location 10 miles north of the accident site (Midland International Airport) were 57 degrees Fahrenheit and a dew point of 30 degrees Fahrenheit. A carburetor icing chart was consulted, and it was determined that this temperature and dew point did fall within the range favorable to the formation of serious carburetor icing at glide power. The U.S. Department of Transportation FAA Flight Training Handbook states in the section under "Descents (Maximum Distance Glides)" that during "power-off descents, the engine should be cleared periodically to prevent excessive cooling and fouling." The engine manufacturer, Teledyne Continental Motors, in their Operator's Manual for the O-200 series engines, states that "carburetor heat is available only at engine outputs well above idle." Part 3 of the Code of Federal Regulations dictates requirements for airworthiness certification, states that an induction de-icing and anti-icing system "provide a preheater which is capable of providing a heat rise of 90 degrees Fahrenheit when the engine is operating at 75 percent of its maximum continuous power."

Probable Cause and Findings

The pilot's failure to periodically clear the engine during an extended glide. Factors were the carburetor icing weather conditions and the lack of suitable terrain for the forced landing.

 

Source: NTSB Aviation Accident Database

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