A worn rudder and insufficient training were just two of the factors that led to a deadly plane crash last year in Kyrgyzstan, involving a tanker from McConnell Air Force Base.
Thursday, the Air Force briefed the media on the investigation surrounding the crash of the KC-135 Stratotanker.
Brigadier General Steve Arquette said the tanker started experiencing issues upon take off.
It started rolling due to a worn rudder, and eventually entered what's called a "dutch roll".
Aarquette says the crew did not realize what was happening and continued to apply the rudder, which the in flight manual does not advise.
"When the autopilot was turned on, both times in fact, it caused larger oscillations, the first time the autopilot was on for four seconds, the second time was for six seconds, each time it resulted in larger oscillations," Arquette said.
Eventually, pressure and movement on the plane caused it to break up mid-air and explode.
Investigators spent a month at McConnell trying to recreate the situation on the flight simulator, but could not.
They now believe more training is needed on how to handle "dutch rolls."
They also noted that the in flight manual may have made it difficult for the crew to find out how to properly hand the dutch roll situation.
All three crew members aboard the tanker were killed.
The crew was from Fairchild Air Force Base in Washington state.