The National Transportation Safety Board questioned witnesses Friday on collision avoidance technology and organizational systems to manage risk. It is the third and final day of investigative hearings probing January’s midair collision between a US Army Black Hawk helicopter and an American Airlines regional jet,

Investigators so far have highlighted several factors that may have contributed to the collision, which left 67 people dead.

On Wednesday, the National Transportation Safety Board (NTSB) began a three-day public hearing into the Jan. 29 crash involving an Army Black Hawk helicopter and American Eagle Flight 5342. Day one brought an emotional and unsettling glimpse into the moments that led to the collision, and the "systemic issues" that may have played a role.