2 fatalities

1994-06-24: Piper PA-31-310 Navajo (N27872) — Roscoe M. Thorne — Palm Beach County Park-Lantana, United States of America

Palm Beach County Park-Lantana, United States of AmericaTakeoff (climb)

On June 24, 1994, a Piper PA-31-310 Navajo (registration N27872) operated by Roscoe M. Thorne was involved in an aviation accident near Palm Beach County Park-Lantana, United States of America during takeoff. 2 people were killed. Investigators recorded the probable cause as: The pilot's impairment of judgment and performance due to drugs, his failure to abort the takeoff after experiencing reduced takeoff performance, and his failure to maintain minimum control speed. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A).

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 1781208910Data APIEditorial standards

The airplane rotated late on a 3,746-ft runway, engines ran rough, then it banked left and crashed at 300 ft. Investigation found pilot impairment from butalbital, improper magneto timing, and a blocked fuel nozzle. Both occupants were killed.

Accident Summary

The airplane began its rotation approximately 3,217 feet down a 3,746-foot runway during takeoff. One or both engines were heard operating roughly. After lifting off, the airplane climbed to about 300 feet above ground level, then banked left, pitched nose-down, and impacted the ground. Both occupants were killed.

Investigation Findings

Post-accident examination of the left engine revealed that after replacing the damaged ignition harness, adjusting the turbocharger density controller, and correcting the magneto-to-engine timing, the engine operated to full rated rpm. The right engine also ran normally following replacement of the magneto, ignition harness, and engine-driven fuel pump. However, the density controller required adjustment to achieve full rated rpm, and the No. 3 cylinder fuel injector nozzle was partially blocked by contaminant.

The right engine magneto contact assemblies were operationally checked and found satisfactory, but the capacitors showed heat damage. The magneto-to-engine timing and internal magneto timing for the right engine could not be determined due to damage.

Toxicological tests on the pilot revealed the presence of butalbital at 1.768 ug/ml in blood and 0.553 ug/ml in urine, along with acetaminophen and salicylate (aspirin) in urine. Butalbital is a prescription barbiturate not approved for use while flying.

Probable Cause

The official probable cause was the pilot's impairment of judgment and performance due to drugs, his failure to abort the takeoff after experiencing reduced takeoff performance, and his failure to maintain minimum control speed. Factors in the accident were a partial loss of engine power due to improper magneto-to-engine timing and a partially blocked fuel nozzle.