The Federal Aviation Administration said on Monday it suspected the firing was retaliation for a safety decision.
"The FAA is taking this action in part because after the company's director of operations voluntarily shut down flights, he was fired," acting administrator Chris Rocheleau said on X.
New York Helicopter Tours' sightseeing helicopter broke apart in midair and plunged into the Hudson River Thursday, killing five tourists from Spain and the pilot.
Rocheleau said the agency also began a comprehensive review of the company's operations.
The review is designed to determine whether an operator complies with regulations and effectively manages safety, and identifies hazards and risks.
The victims included passengers Agustin Escobar, 49, his wife, Mercè Camprubí Montal, 39, and their three children, Victor, four, Mercedes, eight and Agustin, 10.
The pilot was Seankese Johnson, 36, a US Navy veteran who received his commercial pilot's licence in 2023.
