The U.S. Central Command investigation into the Aug. 6, 2011, CH-47 crash in Wardak Province, Afghanistan, is complete.
The investigation confirmed that the primary cause of the accident was an insurgent-fired rocket propelled grenade strike to the aft rotor blade as the helicopter approached its combat landing zone. The investigation determined that operational planning and execution were consistent with previous missions, and that the forces and capabilities were appropriate given the agility required to maintain pressure on insurgent networks.
There was no evidence of a pre-planned ambush.
To read the unclassified executive summary of the investigation, go to: https://www.centcom.mil/images/stories/stories/wardak_executive_summary.pdf