There have been lots of plane crashes lately, which is unsettling to say the least, and some people want to know why they're happening.

“The recent spike falls into the margins of unpredictability,” said Darren Straker, a former head of air accident investigation units in the United Arab Emirates and Hong Kong told Bloomberg News in December. He suggested airline crews could be better trained to respond to so-called outlier events.

Despite recent headlines, U.S. commercial airline travel has become increasingly safe. An American Airlines regional jet collided with a Black Hawk helicopter over the Potomac River, killing 67 people. A private medical jet crashed in Philadelphia, with 7 lives lost.

All 67 victims have been recovered from the Potomac River following a deadly mid-air collision between an American Airlines plane and a military helicopter. 60 victims were passengers aboard American Airlines flight 5342.

Two airport employees have been arrested in connection with what officials said was an unauthorized release of video of last week's fatal plane crash over the Potomac River in Washington, D.C. The footage showing the collision between an Army Black Hawk helicopter and an American Airlines passenger jet was leaked to CNN,