A ‘New York Times’ investigation into the Jan. 29 midair collision between an American Airlines passenger jet and a U.S. Army Black Hawk helicopter found that the captain who was flying the military aircraft was not suffering from any medical impairment.

New details suggest missed instructions played a role in the January mid-air collision between an Army Black Hawk helicopter and a passenger jet in Washington, D.C., that killed 67 people. A new report from the New York Times reveals the pilot aboard the Black Hawk failed to heed a flight instructor’s warning seconds before the crash.