SHUNK, PA, USA
N453D
Beech A23-24
Two non-instrument-rated private pilots and three passengers decided to return home after a weekend visit. A friend tried to dissuade them from flying because of the existing weather conditions, but was told they had to return home because, among other things, the children's school started the next day. The friend then offered to drive home with them, and bring their rental car back. The pilots declined, but assured him they would not fly if the weather was too bad. At the airport, one of the pilots was seen checking the weather computer a number of times, and the group was noted as being 'pretty concerned about the weather.' The airplane departed Elmira where the weather was reported at 1622 hours as 3,600 foot overcast with light rain, and climbed to about 8,500 feet into, or near instrument meteorological conditions. The radar track showed the aircraft transitioning from a climbing right turn approximately 8,500 feet to a rapidly descending right turn. An altitude loss of 1,600 feet in 12 seconds was recorded. It was observed descending from a cloud layer, in a spin, with part of the left wing missing, just before impacting terrain. The pilot-owner was in the left front seat, and the other pilot was in the right front seat. At the time of the accident, the airplane was near its maximum gross weight. Post-crash metallurgical examination of left wing spar fracture surfaces revealed features typical of overstress separation and no pre-existing crack features.
HISTORY OF FLIGHT On September 7, 1998, at 1653 Eastern Daylight Time, a Beech A23-24 Musketeer, N453D, was destroyed when it impacted terrain after an in-flight breakup near Shunk, Pennsylvania. The certificated private pilot-owner, another certificated private pilot, and three additional passengers were fatally injured. Instrument meteorological conditions prevailed at altitude, while visual meteorological conditions prevailed at the accident site. No flight plan was filed for the flight between Elmira/Corning Regional Airport (ELM), Elmira, New York, and New London Airport (N01), New London, Pennsylvania. The personal flight was conducted under 14 CFR Part 91. A friend, who was also a pilot, stated that the occupants of the airplane had stayed overnight at his farm. On the day of the accident, he told them that he, personally, would not want to fly on that day because of the weather. He suggested that they stay another night, but received a collective "no" from the group because school was starting the next day for the children, the wife was in nursing school, and the husband, the additional pilot, had to get back to his business. He then "begged with heart and soul" that they not fly, and offered to drive home with the group, then bring their rental car back. The pilots responded that they would check the weather while at the airport, and would not fly if it was too bad. According to the line manager at Elmira, the weather was overcast when the airplane took off, but it was not raining. The occupants of the airplane were "pretty concerned about the weather" and "the guy in his 30's or 40's" went back to check the weather computer several times. The airport manager stated that at the time of the airplane's departure, he "wondered why they left in that marginal weather." The airplane took off around 1630, and after its departure, there was no contact with it until it was seen by witnesses near the crash site. According to those witnesses, the airplane rapidly descended from a cloud layer with part of one wing missing. It entered a spin and crashed into a cornfield. Several of the witnesses stated that they later saw a wing-like object flutter towards the woods, east of the crash site. The accident occurred during the hours of daylight, and the main ground impact point was located at 41 degrees, 31.91 minutes north, 76 degrees, 45.39 minutes west. PERSONNEL INFORMATION The pilot-owner received his private pilot certificate in January, 1998. He had about 320 hours of total flight time, with approximately 300 hours in the accident airplane. He was 69 years old. The other pilot received his private pilot certificate in March, 1996. His pilot logbooks were not recovered. According to his father, the pilot had between 400 and 500 hours of flight time. He was 39 years old. Neither pilot was instrument rated. According to the airport manager at Elmira, the older of the two men was "the one making the decisions" about the flight. He got into the airplane's front left seat, while the younger man got into the right front seat. There was insufficient evidence to determine which pilot was at the controls during the accident sequence. METEOROLOGICAL INFORMATION Weather recorded at Elmira, at 1622, included a few clouds at 1,700 feet, a scattered cloud layer at 2,500 feet, and an overcast cloud layer at 3,600 feet, with light rain. Witnesses at the accident site stated that the sky there was overcast when the accident occurred. Weather at an airport located 19 nautical miles to the southwest of the accident scene, at an elevation of 529 feet, included a broken cloud layer at 2,900 feet above the ground, and an overcast layer beginning at 3,500 feet above the ground. The National Weather Service provided Composite Reflectivity Images and Echo Tops Images for the approximate time period of the accident. Composite Reflectivity Images showed blue and green colors for several cells in the vicinity of the accident site. According to the Manager of Forensic Services, the blue and green colors indicated light rain. Echo Tops Images in the same area were gray in color, and according to the accompanying scale, depicted echoes at 5,000 feet. The Manager of Forensic Services stated that the echoes reflected precipitation only, and did not represent the cloud tops, which would normally be higher. WRECKAGE AND IMPACT INFORMATION The accident site was located in a valley, about the 1,600 foot level. Rising terrain to the north, south and west ranged from 2,000 to 2,300 feet in elevation. Initial on-site examination of the wreckage revealed that the outboard 6-foot section of the airplane's left wing was missing. Additional wreckage was eventually found, over several months, in an area of approximately 1.5 square miles. The left aileron was 1,150 feet, 203 degrees magnetic, from the main wreckage; the left, outboard wing section was 1,600 feet, 171 degrees magnetic from the main wreckage; and part of the left wing flap was 1,750 feet, 141 degrees magnetic, from the main wreckage. The propeller exhibited chordwise scoring. One propeller blade was curled backwards at the tip, and both blades exhibited "s-pattern" bending. The propeller was still attached to the engine, which exhibited impact damage. All four cylinders were damaged, and the accessory section was destroyed. The crankshaft was bent about 40 degrees to the right, between the casing and the propeller. All cockpit instruments were destroyed. One control yoke was found with the right horn bent forward, and both control yokes had the left horn bent to the right, about 45 degrees. It could not be determined which yoke came from which side of the cockpit. The fuel tanks were split open, and no evidence of fuel was found near the wreckage. However, witnesses said that when they approached the crash site from below, they noticed a heavy odor of fuel. Additionally, it was confirmed that the airplane had been topped off with 43.4 gallons of fuel at Elmira, about 38 nautical miles north of the accident site. MEDICAL AND PATHOLOGICAL INFORMATION Toxicological testing was performed on the pilot-owner by the FAA Toxicology Accident Research Laboratory, Oklahoma City, Oklahoma. Tests for carbon monoxide and cyanide were not performed due to the lack of suitable specimens. Ethanol was detected in muscle and heart specimens, but "in this case [was] from postmortem ethanol production." No additional legal or illegal drugs were detected in the muscle. On September 9, 1998, an autopsy was performed on the pilot-owner under the direction of the Sullivan County Coroner, Eagles Mere, Pennsylvania. TESTS AND RESEARCH Radar A radar plot was created, covering times 1644:47 through 1653:36. The plot revealed that the accident airplane was initially on a southeasterly track. At the beginning of the plot, the airplane was at 7,700 feet; then it gradually climbed to 8,500 feet by time 1650:59. It remained at 8,500 feet through a slight right turn, at 1652:48. The right turn increased, and the airplane passed 8,400 feet at 1653:00. At 1653:12, the airplane was at 8,000 feet, and at 1653:24, when the last radar return occurred, the airplane was still in a right turn, at 6,400 feet. Rate of descent, based on the plot, was about 500 feet per minute between 1652:48 and 1653:00, 2,000 feet per minute between 1653:00 and 1653:12, and 8,000 feet per minute between 1653:12, and 1653:24. Structures The wreckage was subsequently examined by a Safety Board Structures Group. According to the group chairman's report, "...the airplane had an in-flight breakup with the outboard section of the left wing bending upwards with positive torsional loading, and departing the airplane in the aft direction during flight." The group chairman also reported that there was no evidence of fire, soot, or collision with a foreign object during flight. Metallurgy The Safety Board Materials Laboratory examined fragments from the point where the spar separated within the left wing. The factual report stated: "Bench microscope examination of the [mating] fragments revealed the fractures contained features typical of overstress separations. No preexisting crack features were noted on the fractures." Corresponding deformations were found on the mating spar cap fractures. "The deformation directions are consistent with the outboard portion of the cap twisting counterclockwise relative to the inboard portion when looking outboard." ADDITIONAL INFORMATION At the approximate time of the accident, weight and balance computations indicated an airplane weight of about 2,600 pounds. The published maximum gross weight for the airplane was 2,550 pounds. On September 7, 1998, the main wreckage was released to a representative from J.W. Cooley and Associates, Downingtown, Pennsylvania. Additional parts, which were subsequently found over the next several months, were transferred to the main wreckage storage site at Hagerstown Aircraft Services, Incorporated, on January 20, 1999.
The pilot-in-command's attempted flight into known adverse weather conditions, his failure to maintain control of the aircraft, and his exceeding the airframe design limits resulting in separation of the outboard left wing. Contributing factors were clouds, self induced pressure, spatial disorientation, and the lack of instrument certification/experience of both the pilot and pilot/passenger.
Source: NTSB Aviation Accident Database
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