CHI95DTK01

A witness reported that the airplane was flying low altitude aerobatic maneuvers in the vicinity of the accident site. Radar tracking data, available above an altitude of approx 800 ft AGL, also shows a VFR target conducting low altitude aerobatic maneuvers. Examination of the wreckage revealed no evidence of preimpact aircraft or engine malfunction. The airplane had come to rest 132 ft from the first impact with the ground. Toxicological tests revealed 0.031 ug/ml brompheniramine and 0.012 ug/ml diphenhydramine in the blood specimen. Therapeutic levels are 0.016-0.070 and 0.100 respectively. Brompheniramine and diphenhydramine (antihistamines) are active ingredients in many nonprescription cold and allergy medications, and can cause drowsiness.

History of flight

On January 8, 1995, about 1600 central standard time, a Gay RV-4 airplane, N29PG, was destroyed when it impacted the terrain while maneuvering near Lennox, South Dakota. The solo private pilot sustained fatal injuries. The personal flight originated in Sioux Falls, South Dakota at 1537 and was conducted under 14 CFR Part 91. The planned destination was Lennox, South Dakota. A flight plan was not filed and visual meteorological conditions prevailed.

During a personal interview on January 11, 1995, a witness stated that between 1555 and 1600, she observed a blue and white airplane heading south. It climbed, did a spiral turn, and then came back down heading north "at a lower altitude than most airplanes fly."

Radar tracking data provided by the Minneapolis Air Route Tracking Control Center shows the airplane departed southbound from Sioux Falls at 1537. The target maneuvered in a series of aerobatic maneuvers in the vicinity of the accident site. Radar coverage was available down to an altitude of approximately 2,100 feet MSL. The elevation of the accident site was approximately 1,300 feet MSL.

Wreckage and impact information

Post accident examination revealed compression of the lower nose and right wing. Both elevator counterweights and the right aileron were separated. The weighted leading edge of both ailerons were distorted. The wreckage path followed a heading of 085 degrees with a distance of 105 feet between the first two ground scars. The aircraft came to rest 132 feet from the first impact on a heading of 187 degrees.

All of the prop bolts were sheared off at the inboard end of the propeller extension. The outboard face and leading edge of both propeller blades exhibited rotational damage. The right main wheel assembly was torn off its attachment point. Both wheel bearings and the wheel retaining nut were intact on the strut. The main wing spar below and to the right of the pilots seat was distorted.

All of the flight control surfaces and flight controls were intact and operational. No evidence of preimpact malfunction was discovered.

Inspection of the engine revealed the left magneto impulse coupling operated normally. Spark from all leads was confirmed on both magnetos. The carburetor was separated in an aft direction, however, remained attached to its linkages. The inlet fuel fitting was broken. Fuel was found in the fuel line from the firewall to the engine driven fuel pump. All spark plugs were normal. There was no evidence of an engine malfunction prior to impact.

Medical and pathological information

Autopsy of the pilot was conducted on January 1, 1995, by LCM Pathologists, P.C., 1212 S. Euclid Ave., Sioux Falls, South Dakota. The results of FAA toxicological testing were negative for all tests conducted except for 0.031 (ug/ml, ug/g) Brompheniramine and 0.012 (ug/ml, ug/g) Diphenhydramine detected in the blood specimen. Brompheniramine and Diphenhydramine were detected in the urine specimen.

According to a NTSB National Resource Specialist, the therapeutic level for Diphenhydramine is approximately .100 (ug/ml, ug/g) and the therapeutic level for Brompheniramine is .016 to .070 (ug/ml, ug/g). Brompheniramine and Diphenhydramine are listed in the Physicians' Desk Reference as active ingredients in many nonprescription cold and allergy medications.