NYC03FA176 · Grumman AA-5B

The pilot attempted an ILS approach, which consisted of an inbound, 331-degree course, magnetic. The minimum glideslope crossing altitude at the initial approach fix was 4,484 feet msl. Radar data indicated the airplane tracked inbound on headings varying from 360 degrees to 270 degrees. Approximately 6.7 miles from the initial approach fix, the airplane descended from 4,600 feet to 3,400 feet, at a rate of 850 fpm. The last radar hit was recorded at 3,400 feet, approximately 4.7 miles from the initial approach fix. The airplane was located about 11 miles from the end of the runway, at an elevation of 2,461 feet, about 300 feet below the peak of a ridgeline. Examination of the airplane revealed no mechanical deficiencies. According to the pilot's toxicology test results, 6.51 (ug/ml, ug/g) of DESIPRAMINE was detected in his blood, and DESIPRAMINE and IMIPRAMINE were detected in his urine. The pilot's wife reported that the pilot had been taking Desipramine for approximately 10 years, to treat depression. She stated that she was a doctor and had prescribed the Desipramine to him. A review of the pilot's FAA medical file revealed he never reported taking Desipramine, and never reported any history of mental disorders. Imipramine is a prescription antidepressant, and often results in sedation and psychomotor impairment in healthy adults. Desipramine is a metabolite of imipramine and a prescription antidepressant in its own right. The levels of desipramine found in the pilot's toxicology report were more than 20 times the expected level for chronic use of a typical dose. Nonfatal overdose effects of desipramine, at amounts lower than reported on the pilot's toxicology, have resulted in seizures, coma, low blood pressure, and electrocardiographic (EKG) abnormalities.

Verbatim NTSB analysis and probable cause from the NTSB dataset