Accident Sequence
A twin-engine helicopter was conducting a cruise flight over the Gulf of Mexico when it experienced a sudden nose-down pitch and entered an uncontrolled descent. The aircraft struck the water in an inverted attitude and sank to a depth of approximately 380 feet.
Examination Findings
Following recovery of the wreckage, investigators examined the helicopter and identified several anomalies. An incorrect hydraulic switch guard was found holding the test switch in the reset position, which electrically isolated hydraulic system number two from operation. The hydraulic module was configured in the number one hydraulic system. Further inspection revealed a defective micro-switch within the outboard lateral guide assembly of the hydraulic module.
Compliance Issues
The investigation also determined that the operator had not complied with a required service bulletin for the hydraulic module. The bulletin specified mandatory modifications or inspections that were not performed, contributing to the degraded state of the system.
Conclusion
The findings indicate a combination of mechanical defects and maintenance non-compliance, though no explicit probable cause was stated in the source. The helicopter was not recovered with any flight data recorder or cockpit voice recorder information, and no additional contextual details were provided.