However, in January 2010, the NTSB issued its final report finding that the crash’s probable cause was Carson’s intentional understatement of the helicopter’s empty weight; alteration of the power-available chart to exaggerate the helicopter’s lift capability; the practice of using unapproved, above-minimum-specification torque in performance calculations that, collectively, resulted in the pilots’ relying on performance calculations that significantly overestimated the helicopter’s load-carrying capacity and that did not provide an adequate performance margin for a successful takeoff; and insufficient oversight by the USFS and the FAA.

[2] The NTSB report also noted contributory factors that included the 1965 helicopter’s lack of crash-resistant fuel tanks and outdated seats.

[3] In 2012, a jury ordered General Electric, the manufacturer of the helicopter’s engines, to pay $69.7 million to William Coultas, the surviving pilot, his wife, and the estate of Roark Schwanenberg.

[4] The trial stemmed from Coultas' belief that a contaminated fuel control unit on the aircraft’s number two GE CT58-140-1 engine caused the crash.

Metheny pled guilty in 2014 to one count each of filing a false statement and of conspiracy to commit mail and wire fraud, and was sentenced to 12 years and 7 months in prison.