Structural failure in thunderstorms kills two

These February 2004 Accident Reports are provided by the National Transportation Safety Board. Published as an educational tool, they are intended to help pilots learn from the misfortunes of others.

Aircraft: Piper Malibu.

Location: Arlington, Ala.

Injuries: 2 Fatal.

Aircraft damage: Destroyed.

What reportedly happened: The pilot obtained a weather briefing from the flight service station, then filed an instrument flight plan. He had 5,021 hours, including 883 hours in the accident aircraft. The briefer advised the pilot of the potential for occasional moderate turbulence between FL240 and 37,000 feet. He also was advised of a Convective SIGMET for embedded thunderstorms. He took off. The controller instructed the pilot to climb to FL250, then amended the climb clearance to FL240. The pilot acknowledged the clearance. Fifteen seconds later, radar data showed the airplane at 24,000 feet on a northwest heading. Moments later the aircraft entered a right descending turn. The controller, noting that the aircraft was descending and turning when it was not supposed to, tried to contact the pilot, but there was no response. The plane continued to descend and disappeared from radar. The wreckage was located the next day, scattered over an area a half-mile wide.

Based on the overstress fractures of several components found in the wreckage, investigators determined that the airframe design limits were exceeded and the aircraft came apart in flight. The Pilot’s Operating Handbook states the maximum structural cruising speed is 173 knots indicated. The co-pilot airspeed indicator at the crash site indicated 180 knots at the time of structural failure.

Probable cause: The pilot’s inadequate in-flight planning and his failure to maintain aircraft control, resulting in an in-flight encounter with a thunderstorm and exceeding the design limits of the aircraft.

Aircraft: Cessna 182RG.

Location: Elberfeld, Ind.

Injuries: None.

Aircraft damage: Destroyed.

What reportedly happened: The pilot conducted a preflight examination of the aircraft, then launched for pipeline patrol. Approximately one hour and 20 minutes into the flight, he smelled smoke. He discovered smoke coming from beneath the instrument panel on the left side. He tried to ventilate the cabin by opening his door. Flames appeared on a wire bundle under the panel. He used the fire extinguisher to douse the flames, then turned toward the closest airport, which was about nine miles away. The cockpit filled with black smoke. The pilot placed his head outside the window to navigate and breathe. While doing this he noticed flames coming from beneath the engine cowl. He made an emergency landing in a field. He was able to evacuate the airplane before the fire engulfed it. Because of the extent of fire damage, investigators were not able to determine the cause of the fire.

Probable cause: The in-flight fires in the cabin and engine compartment for undetermined reasons during cruise flight.

Aircraft: Piper Arrow.

Location: Pine Mountain Club, Calif.

Injuries: 1 Fatal.

Aircraft damage: Destroyed.

What reportedly happened: The pilot had recently received his private pilot’s certificate but did not possess an instrument rating. He had approximately 100 hours experience. He was attempting to fly from Long Beach to Sacramento at night. Friends said he had made the night flight before, always using the same route that paralleled the highway then went through the same mountain pass. There was no record of the pilot getting a weather briefing. At the time of the flight AIRMETS were in effect along the route for turbulence, icing, and mountain obscuration. Radar data showed the airplane took off, meandered a little bit, then headed north toward the mountains. The aircraft’s course paralleled an interstate highway, leveling off at 9,500 feet msl. The pilot turned west, and climbed to 10,000 feet. He contacted air traffic control and requested VFR flight following and an altitude of 10,500 feet. He told ATC that he was diverting to the west for cloud avoidance. He then requested a descent to 8,500 feet. ATC approved the descent at the pilot’s discretion and advised him to maintain VFR. As the airplane proceeded west, radar showed the aircraft descending through 9,000 feet at a rate of 1,100 feet per minute. The pilot continued his descent and requested a cruising altitude of 4,500 feet. ATC advised the pilot that he was in an area of high terrain. He said he could see the ground but he didn’t have good forward visibility and requested a vector to better weather. ATC advised him to head north toward lower terrain and warned him that he was below the minimum vectoring altitude for the area. He responded that he could see pretty well and would take a northbound heading. The last radar return showed the aircraft at an altitude of 7,100 feet. There were no further transmissions from the pilot. The airplane hit a mountain slope at an elevation of 6,683 feet msl and on a heading of about 350°. A witness on the ground at Pine Mountain Club reported hearing an airplane flying low and fast in the vicinity of the crash site, but said that he could not see it because of snow showers. Another witness saw the explosion and fireball just below the clouds when the aircraft hit the slope.

Probable cause: The pilot’s continued visual flight into adverse weather conditions at night, which resulted in an in-flight collision with mountainous terrain. The failure to obtain preflight weather information for the route of flight was also a factor.

Aircraft: Cessna 150.

Location: Longview, Wash.

Injuries: 1 Serious.

Aircraft damage: Substantial.

What reportedly happened: During the pre-flight inspection the pilot noticed that the fuel tanks were half full. He took off without refueling and entered the pattern for a touch and go. After the touch and go he decided to fly over a local river to look for a barge that had been reported missing. He lost track of time and when the engine quit he realized that the plane had run out of fuel. He made a forced landing in an open field. During the landing roll, the nose wheel hit a ditch and the aircraft nosed over.

Probable cause: Fuel exhaustion while maneuvering, as a result of the pilot’s inadequate in-flight decision/planning.

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