(CNN) - The NTSB is blaming pilot error for the helicopter crash that killed country music star Troy Gentry last September in New Jersey.
The agency issued its final report on the crash Tuesday.
It says the pilot reported trouble controlling the engine's RPM while in flight.
Two instructors and an FAA inspector advised him to perform a landing known as a "run-on landing" in the middle of the airfield and keep his engine running until he was over the runway.
The pilot refused and instead turned off the engine a quarter mile away. The helicopter then began to nosedive almost 1,000 feet in the air.
The report also notes maintenance failure was a contributing factor to the crash.