BELVIDERE, SD, USA
N3966M
Piper PA-28-201T
During a weather briefing, the pilot was advised that 'the forecast across South Dakota for the eastern third of the state 2,500 AGL scattered to broken with 5,000 overcast with occasional visibilities three to five miles in light snow....' During the flight the airplane experienced an in-flight breakup. The wings were fractured at the roots with evidence of positive overload. The empennage was separated from the tail cone with evidence of torsional overload. According to local residents, 'low' visibility existed in the vicinity of the accident due to fog and blowing snow. Airplane weight and balance calculations indicate the center of gravity was beyond the aft center of gravity limit. Toxicological tests detected dextromethorphan in the liver fliud (0.009 ug/ml) and kidney fluid (0.007 ug/ml). Pseudoephedrine was also detected in liver fluid. Additionally, a substance was detected, but not quantified, which according to the manager of the FAA Toxicology and Accident Research Laboratory 'appears to be an ergotamine type compound.' Examination of the pilot's personal medical records revealed medical treatment for an 'asthma flare' 17 days prior to the accident.
HISTORY OF FLIGHT On November 23, 1995, about 0800 mountain standard time, a Piper PA-28-201T, N3966M, was destroyed during an inflight breakup near Belvidere, South Dakota. The private pilot and three passengers sustained fatal injuries. The personal, 14 CFR Part 91 flight originated in Sioux Falls, South Dakota, at 0730 central standard time, with a planned destination of Rapid City, South Dakota. Witnesses reported moderate snow showers and low visibility near the accident site at the time of the accident. A VFR flight plan was filed. METEOROLOGICAL INFORMATION The pilot telephoned the Fort Dodge Flight Service Station (FSS) on November 22, 1995, at 1813. During the weather briefing, the briefer advised "flight precautions over South Dakota for light to moderate rime or mixed icing 3,000 to 15,000 feet... ." The pilot commented "...I think we'll leave at daylight then...I'll call back for another briefing." The pilot called the Fort Dodge FSS again on November 23, 1995, at 0557. The briefer advised "the forecast across South Dakota for the eastern third of the state 2,500 AGL scattered to broken with 5,000 overcast with occasional visibilities three to five miles in light snow, the western two thirds of the state expecting 1,500 AGL scattered to broken with 2,500 to 3,500 overcast occasional visibilities three to five miles, light snow, light freezing rain... ." The surface advisory recorded at 0749 in Pierre, South Dakota, 60 miles northeast of the accident site, measured scattered clouds at 1500 feet, and estimated ceilings of 4,000 feet, with visibilities of three miles in light snow and fog. The Jackson County Sheriff reported that, at the time of the accident, the visibility in the vicinity of the accident site was very low due to blowing snow. He described it as severe enough to make driving difficult. WRECKAGE AND IMPACT INFORMATION Preliminary examination of the wreckage by initial responders revealed a small collection of ice on one of the fuel tank vents. No structural icing was present. The NTSB on-scene investigation began about 0900 on November 24, 1995. The wreckage was located four miles northwest of Belvidere, South Dakota, in a grassy pasture. The wreckage was scattered in a northeasterly direction. The first item in the wreckage path was the right wing, followed by the left flap, fragments of the empennage, and the right wing. The aft fuselage, including the cabin, was located 480 yards from the right wing. The nose section, forward of the front seats, was located 530 yards from the right wing. A checklist, papers, and fragments of interior were scattered for approximately 1/2 mile to the northwest. Both wing spars were fractured near the root at the outboard bolt line. The fractures were bent in the positive direction. The lower skin of both wings were buckled at the midspan. Paint transfer on the right side of the fuselage matched the upper surface of the right flap. The flap was bent in an arc that matched the contour of the upper fuselage. The forward fuselage was separated near the wing leading edge in the vertical plane of the forward wing attach fittings. The empennage was separated from the tail cone. The fractures in the empennage were bent torsionally about the longitudinal axis of the airplane. Visual examination of all fracture surfaces disclosed no evidence of progressive failure or corrosion. The propeller exhibited minor bending. Examination of the engine, engine controls, and flight controls revealed no evidence of mechanical malfunction. The vacuum pump rotor was fractured. All six vanes were in position and were intact. The vacuum gyros exhibited rotational scoring around the circumference. The pitot tube was intact with no evidence of obstruction. MEDICAL AND PATHOLOGICAL INFORMATION Autopsy of the pilot was conducted at the Clinical Laboratory of the Black Hills, 2805 Fifth Street, Suite 210, Rapid City, South Dakota 57701. FAA toxicological testing yielded positive results for dextromethorphan and pseudoephedrine. Additionally, a substance was detected, but not quantified, which according to the manager of the FAA Toxicology and Accident Research Laboratory "appears to be an ergotamine type compound." Examination of the pilot's personal medical records revealed he was examined by his personal physician on November 6, 1995. The chart indicated "current medications include Aerobid M two sprays twice a day, Serevent two sprays twice a day, frequent Alupent, and intranasal Flonase" and "IMPRESSION: Asthma flare." The treatment listed on the chart indicated a "Terbutaline nebulizer treatment", "Depo-Medrol 200 mg IM", "Prednisone 20 mg four day short course", and a flu shot. ADDITIONAL INFORMATION A fuel receipt, discovered in the wreckage, indicated 50.5 gallons of "avgas" were onloaded on November 23, 1995, in Sioux Falls, South Dakota. Airplane weight and balance calculations indicate the gross weight of the airplane was about 2,722 pounds and the center of gravity was approximately 90.9 inches at the time of the accident. The pilot operating handbook specifies an aft center of gravity limit of 90.0 inches for all airplane weights. Parties to the investigation were the Federal Aviation Administration Flight Standards District Office, Rapid City, South Dakota, The New Piper Aircraft, Inc., and Teledyne Continental Motors. Following the on-scene portion of the investigation, the wreckage was released to a representative of Loss Management Services, Inc.
the pilot's attempted visual flight into instrument meteorological conditions, his failure to maintain control of the airplane, and exceeding the design stress limits of the airplane. Factors in the accident were: the snow and fog, and the aft airplane center of gravity.
Source: NTSB Aviation Accident Database
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