The report, which was released Friday, cited several errors made by multiple crew members that led to an inoperative engine, a left wing stall and the plane eventually nosediving onto Ga. 21 shortly after takeoff from Savannah/Hilton Head International Airport on May 2.
The nine people killed were airmen in the Puerto Rico National Guard.
The Lockheed WC-130 Hercules was assigned to the 156th Airlift Wing, which is based out of Muñiz Air National Guard Base. The plane, which was more than 60 years old, was making its final trip to Davis-Monthan Air Force Base in Arizona for retirement.
"The purpose of the investigation was to identify the cause and contributing factors that led to this tragic and unfortunate incident,” Accident Investigation Board team leader Brig. Gen. John C. Millard told WSB-TV.
"By conducting a thorough review and investigation, we hope to provide answers to the families of brave airmen that lost their lives and prevent future occurrences and tragedies."
Millard’s team spent about a month reviewing an array of evidence, including interviews, logs, video, briefing material and inspection of aircraft wreckage, WSB reported.