collided with a gyrocopter at an air show, killing two and injuring two more. robert is the former chairman of the national transportation safety board. is there any difference between the crashes we re seeing involving bigger planes versus smaller planes? is there a safety difference? there is. but general aviation is generally very safe. reporter: and the ntsb typically reports around 1,000 plane crashes across the country each year, but important to note, so far this year we ve seen about half that number, and that includes everything from military to smaller aircraft, just like we saw this weekend. jericka? great information. thank you. straight ahead on the cbs weekend news, why this hot summer could be the coolest one we have left. plus, the latest on barbie s box office bonanza. and later, a royal census of swans and w why it ss a an