St. Charles Parish Sheriff Greg Champagne identified the dead man in a statement Monday as 33-year-old Ryan Lamont Cardwell of Watonga.
Watonga is located northwest of Oklahoma City. Champagne says Cardwell was a passenger in the helicopter.
He says Cardwell worked for a company called Air2 that was contracted by Entergy to perform services on the Entergy transmission line right-of-way where the crash occurred.
The injured pilot, 38-year-old Kenneth Gestal of Florida and crewman, 33-year-old Chance Mills of Missouri were taken to a nearby hospital. The sheriff's office says Mills injuries appeared to be severe.
The helicopter crashed Sunday in a marsh along a power line right-of-way in Boutte, about 10 miles southwest of New Orleans.
The National Transportation Safety Board is investigating the crash.
The Associated Press contributed to this report.