American Airlines flight 5342 was preparing to land on runway 33 at the Ronald Reagan Washington National Airport last night when it collided with a military helicopter. There were no survivors - how could such a tragedy happen?   
  
On this episode, Niall Paterson is joined by former Royal Air Force Air Vice-Marshal Sean Bell to look at what might have led to the mid-air collision.   
  
Niall also speaks to Dr Michael McCormick, a US air traffic control expert who has developed policies for commercial aircraft to operate in the same airspace as the military. 
 
Producers: Soila Apparicio, Natalie Ktena 
Editor: Wendy Parker