Federal investigators revealed Wednesday that the Black Hawk helicopter involved in the deadly DCA crash may have misreported its altitude by more than 100 feet, a flaw the Army had long known about but never formally documented.

It was the first acknowledgment by the Federal Aviation Administration of a possible error by the controller in the moments before the collision that claimed 67 lives.

The maneuver might have taken the helicopter out of the direct path of a passenger jet as it was trying to land at Reagan Airport on Jan. 29.