A jet collided with an Army helicopter while approaching the Ronald Reagan National Airport near Washington. Here are some things to know about the collision.

The bodies of 27 passengers from the jet and one from the helicopter have been recovered, said the fire chief in the US capital

The U.S. Army described the helicopter as a UH-60 Blackhawk based at Fort Belvoir in Virginia. The helicopter was on a training flight. Military aircraft frequently conduct training flights in and around the congested and heavily-restricted airspace around the nation’s capital for familiarization and continuity of government planning.