The U.S. Army has announced a suspension of non-critical aviation flight units for training following two fatal helicopter crashes in the past month. Lt. Col. Terence Kelley, an Army spokesperson, said the suspension of air operations was effective immediately, with units grounded until they complete the training. The Army said in a news release that the safety of their aviators is their top priority, and the stand down is an important step to make certain they are doing everything possible to prevent further accidents. It is unclear when the stand down will be lifted.