With all the discussion recently over the incident near ORD, it seemed appropriate to take a look at the official FAA reports of Near Mid Air incidents. The most recent incident is not listed since the most recent freeze date is 31 Aug 2017.

7957 incidents between 1 Jan 1987 to 31 Aug 2017

2988 reported by GA (Part 91)
2106 reported by US air Carriers
1445 reported by US Military
765 reported by Air Taxi or Commuter aircraft (Part 135)
207 reported by Foreign air carriers (Part 129)
7 reports by gliders (6 in CA and 1 in HI)
439 by other various aircraft types
Interesting that almost half of those reporting a near miss were NOT on an instrument flight plan but were flying VFR.
4754 of those reporting a near miss were on an instrument flight plan.
10 others were under SFR or Defense VR and likely talking to ATC.


Other (second) aircraft analysis
More than half (4000+) were GA aircraft
25 were gliders (23 glider reports and 2 sailplane reports)
20 of the 23 glider incidents were considered no hazard or potential only
3 were considered Critical
May 1993 in Boulder, CO (14,000 ft) (reported by Part 135 Commuter)
May 1994 Wilmington, OH (5,900 ft) (reported by Part 91)
August 1997 Lancaster, TX (5,000 ft) (reported by Part 135 Commuter)
2 listed under Sailplane were both considered Critical
August 1995, Elmira NY (6,000 ft) (reported by GA Part 91)
June 2004, Saratoga Spring, UT (11,000 ft) (reported by Part 125)

Average Altitude for all incidents was 4985 feet
132 incidents at FL18 and above
599 incidents between 10,000 and FL18
5076 incidents below 10,000 ft
396 incidents occurred within 500 ft of the ground

Perhaps most scary is that 105 Drones encounters were reported since May 2014 with more than half of those (67) in the last 12 months
Average Drone altitude was 4138 ft with one reported as high as FL250

Gliders account for 0.1% of those reporting and 0.3% of those reported

Most dangerous place to fly --- CA with 1651 incidents (20.7% of the total)