Incident Overview
The accident occurred when an airplane, after being observed passing from north to south under the Queen Isabel Causeway Bridge (spanning between Port Isabel and South Padre Island, Texas), executed a 180-degree turn and approached the bridge from the south for another pass. During this second pass, the aircraft struck a concrete bridge pylon and column, then descended uncontrolled into the water.
Examination Findings
No preimpact mechanical problem was discovered. The airplane's last annual inspection was dated July 27, 1995. Neither of the two pilot-rated occupants held a valid FAA medical certificate.
Toxicology Results
Toxicology testing of the right-seat occupant's blood revealed: 0.006 mcg/ml tetrahydrocannabinol (active substance in marijuana), 0.006 mcg/ml tetrahydrocannabinol carboxylic acid (inactive metabolite), 0.087 mcg/ml cocaine, 1.809 mcg/ml benzoylecgonine (inactive metabolite of cocaine), and 0.095 mcg/ml diphenhydramine (a sedating over-the-counter antihistamine).
Testing of the left-seat occupant revealed cocaethylene (a substance formed when cocaine and alcohol are ingested around the same time) in the liver fluid; 65 mg/dl ethanol in vitreous fluid; and in the blood: 143 mg/dl ethanol, 0.133 mcg/ml cocaine, and 0.066 mcg/ml benzoylecgonine.