...an FAA report obtained by the Associated Press says staffing in the tower was "not normal" at the time of the collision.
...
The ABC7 I-Team has reported on serious concerns from federal lawmakers about understaffing in the air traffic towers. For instance, in November staffing at Air Route Traffic Control Center in Aurora, where planes across the Midwest are sequenced and separated, was at 82%, according to the union representing air traffic controllers.

The National Air Traffic Controllers Association union said air traffic control staffing nationwide decreased by 9% from 2011 to 2023, while flights increased during that same time period.

According to air traffic control data obtained by The Washington Post, a similar incident almost unfolded at the airport just 24 hours earlier. Per that data, the Post reported, a Republic Airways flight jet trying to land at DCA had to make a second approach when a helicopter appeared near its flight path.