Two Small Planes Collide Mid-Air Near Colorado Airport

Two small planes smashed into each other mid-air in Colorado on Sunday ... sending smoke billowing into the sky and igniting one of the aircraft.

The Federal Aviation Administration tells TMZ ... a Cessna 172 and an Extra Flugzeugbau EA300 collided around 12:10 PM near Fort Morgan -- about 80 miles northeast of Denver. The FAA says two people were aboard each aircraft at the time.

The Morgan County Sheriff's Office says one plane caught fire as it came down while the other was heavily damaged.

So far, there's no word on the conditions of the four people on board the planes. The FAA and National Transportation Safety Board are investigating with the NTSB taking the lead.