Aviation Accident Summaries

Aviation Accident Summary CHI03IA069

Goodland, KS, USA

Aircraft #1

N9247L

Piper PA-31-350

Analysis

The twin engine airplane operated under FAR Part 135 sustained minor damage during a forced landing to a field after a partial loss of power to both engines during cruise flight. The destination airport was about 70 miles from the takeoff airport. The pilot reported that while climbing through 5,600 feet msl, the right engine started running rough. The right engine's manifold air pressure (MAP) eventually dropped to 18 inches. He did not secure the right engine since it was still producing some power, but he increased the left engine's MAP to 35 inches to compensate for the loss of power on the right engine. He reported the airplane was approximately 25-30 miles from the departure airport, but the pilot continued the flight to the destination airport. Approximately 20 miles from the destination airport the left engine began running rough and the left engine's MAP quickly dropped to 18 inches of MAP. The pilot executed a forced landing to a field about nine miles from the destination airport. He reported, "Assured that I could not make the airport, I secured both engines. Simultaneously, [I] selected the best landing site I could see." The pilot lowered the landing gear after securing both engines. The airplane landed in the middle of a field and the landing gear collapsed during rollout. The airplane skidded to a stop on its belly, receiving only minor damage. The airplane was lifted up on its main landing gear by a crane and it was towed to the airport. An inspection of the fuel system and engine revealed no anomalies. The fuel tanks contained fuel and no contamination was found. The left and right engines were started and an engine ground run revealed no anomalies on the left engine. The right engine ran normally except the right engine could only develop 30-32 inches of MAP. The oil line going to the right engine's waste gate differential control was capped off, and then the engine produced 40 inches of MAP. The FAA approved a ferry flight. The airplane departed and flew for 30 minutes in the local pattern prior to departing. The flight continued to Denver without incident or any engine anomalies. An uncontrolled airport with lighted runways was located 30 miles from the takeoff airport and 40 miles from the destination airport.

Factual Information

On February 12, 2003, at 1908 mountain standard time, a Piper PA-31-350, N9247L, operated by Key Lime Aviation, sustained minor damage during a forced landing to a field near Goodland, Kansas, after a partial loss of power to both engines during cruise flight. The commercial pilot was not injured. The Title 14 CFR Part 135 cargo flight departed Mc Cook Municipal Airport (MCK), Mc Cook, Nebraska, at 1847, en route to Goodland Municipal Airport (GLD), Goodland, Kansas. Night visual meteorological conditions prevailed at the time of the accident. No flight plan was filed. The pilot reported he had refueled at MCK and had about 133 pounds of cargo on board the airplane. The pilot reported that GLD was 63 nautical miles from MCK. The pilot reported that while climbing through 5,600 feet mean sea level (msl) for 6,000 feet msl, the right engine started running rough. He switched the fuel tank from the main tank to the auxiliary tank, and cycled the emergency fuel pump, but it did not produce any change to the rough running engine. He reported he set the left and right engines' manifold pressure to 30 inches of manifold air pressure (MAP) for cruise flight, but soon after the right engine's MAP started dropping. It eventually dropped to 18 inches MAP. He did not secure the right engine since it was still producing some power, but he increased the left engine's MAP to 35 inches to compensate for the loss of power on the right engine. He reported the airplane was approximately 25-30 miles from MCK, so he continued the flight to GLD. He reported that the left engine then started to run rough. The pilot reported that the airplane was approximately 20 miles from GLD so he decided to continue on to GLD. He reported that the left engine's MAP quickly dropped to 18 inches of MAP. He performed the emergency restart checklist while making an emergency radio call on GLD's radio frequency, 122.95. He reported that both engines were still only producing 18 inches of MAP. He tried to find a place to land, but since it was night, he had only a limited view of the terrain. He reported, "Assured that I could not make the airport, I secured both engines. Simultaneously, [I] selected the best landing site I could see and called my position 030 [degrees] from GLD at 9 miles. I put the gear down, turned left approx. 45 degrees, [and the] touchdown was controlled wings level." The airplane landed in the middle of a field and the landing gear collapsed during rollout. The airplane skidded to a stop on its belly, receiving only minor damage to the aircraft. The airplane was lifted up on its main landing gear by a crane and was towed to GLD. A Federal Aviation Administration (FAA) airworthiness inspector examined the airplane. The inspection of the fuel system revealed no anomalies. The fuel tanks contained fuel and no contamination was found. The left and right engines were started and an engine ground run revealed no anomalies on the left engine. The right engine ran normally except the right engine could only develop 30-32 inches of MAP. The oil line going to the right engine's waste gate differential control was capped off, and then the engine produced 40 inches of MAP. The FAA approved a ferry flight to Denver. The airplane departed GLD and flew for 30 minutes in the local pattern prior to departing to Denver. The flight continued to Denver without incident or any engine anomalies. The Atwood-Rawlins County Airport (ADT), Atwood, Kansas, located 30 miles from the takeoff airport and 40 miles from the destination airport, was along the direct route of flight between MCK and GLD. Runway 16/34 at ADT is a lighted asphalt runway that is 5,0001 feet long 75 feet wide.

Probable Cause and Findings

The partial loss of engine power to both engines for undetermined reasons, and the pilot's improper in-flight decision to not land at the nearest available airport.

 

Source: NTSB Aviation Accident Database

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