Incident Overview
A helicopter operating a night medical flight from Shreveport, Louisiana, to Lafayette, Louisiana, via Alexandria, impacted the ground after the pilot experienced an in-flight anomaly. The occurrence took place during a dark night while the aircraft was following Interstate 49 southbound over the northbound lanes.
Sequence of Events
The helicopter had descended to 500 feet MSL due to weather conditions. The pilot slowed the aircraft to 70 knots to keep pace with traffic. The medical crewmember reported feeling a shudder similar to what occurs when a helicopter decelerates through effective translational lift. The pilot was heard uttering an expletive, and the helicopter began a left turn. The crewmember observed sparks overhead and felt plexiglass strike him. Subsequently, the helicopter impacted the ground. During the sequence, the crewmember lost visual orientation of the helicopter's position relative to the ground.
Weather Conditions
According to the medical crewmember, the ceiling was approximately 550 to 600 feet, and visibility was about 2 miles. The company's Operations Manual specifies that for cross-country air ambulance operations during nighttime hours, the minimum ceiling is 1,000 feet and minimum visibility is 3 miles. Any flight outside the local flying area is considered a cross-country operation.
Examination
Post-incident examination of the helicopter revealed no structural or mechanical anomalies.