3 fatalities

Dual Instruction Flight Crashes Into Swamp After Uncontrolled Descent (N79NU)

Manatí, Puerto RicoFlight

On February 11, 1996, a Rockwell Shrike Commander 500 (registration N79NU) operated by Hill Construction was involved in an aviation accident near Manatí, Puerto Rico in flight. 3 people were killed. Investigators recorded the probable cause as: Failure of the flight crew, for undetermined reasons, to recover from a stall and resulting uncontrolled descent. This resulted in the aircraft colliding with the terrain while in a 45-60 degree nose down attitude at a slow speed. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A).

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 2026-06-11Data APIEditorial standards

A dual instruction flight crashed into a swamp after an uncontrolled descent. Post-crash tests found no mechanical failure, while toxicology revealed drug and medication use by the occupants.

Accident Overview and Witness Accounts During a dual instruction flight intended to orient the student to the aircraft, witnesses reported the airplane traveling from east to west at a slow speed. The right wing initially dropped before returning to level, followed by a descent in a 45- to 60-degree nose-down attitude. As the aircraft descended, the wings rolled back and forth, and an object was observed moving on the outboard right wing area. The aircraft did not recover and struck the ground nose-first at a slow speed in a swamp area. ## Post-Crash Examination and Toxicology Findings Post-crash examination found no evidence of pre-crash mechanical malfunction or failure in the aircraft structure, flight controls, engines, propellers, or systems. The rudder trim was in the neutral position, and the elevator trim was set for 70% of the aircraft's nose-up trim. Toxicology tests showed the dual student had 0.319 ug/ml of marijuana in urine, 0.010 ug/ml of marijuana in blood, and 10.90 ug/ml of acetaminophen in blood. The pilot-in-command/flight instructor had 47.90 ug/ml of acetaminophen and 89.20 ug/ml of salicylate in urine. The pilot-in-command had hand injuries consistent with operating the aircraft's controls at the time of the accident, while the dual student did not have hand injuries consistent with operating the controls.

Probable cause

Failure of the flight crew, for undetermined reasons, to recover from a stall and resulting uncontrolled descent. This resulted in the aircraft colliding with the terrain while in a 45-60 degree nose down attitude at a slow speed.