American Airlines CEO Robert Isom said that Flight 5342 was on a normal approach to Reagan National Airport and that “we don’t know why the military aircraft came into the path of the PSA aircraft,” one of the many questions the Fort Worth-based carrier is asking in the wake of the tragedy that took 67 lives.

In the aftermath of the midair collision between an American Airlines plane and a U.S. Army Black Hawk helicopter on Wednesday, Jan. 29, the Federal Aviation Administration is indefinitely restricting helicopter flights in the vicinity of Washington,