Colorado Aviation Accidents & Incidents

HISTORY OF FLIGHT
On March 23, 2012, about 1143 mountain daylight time, a Cessna 172S, N10468, and a Cessna 180, N9325C, were substantially damaged during a mid-air collision near Longmont, Colorado. The Cessna 172 impacted an embankment adjacent to a two-lane roadway, about 5 miles east of the Vance Brand Airport (LMO). The Cessna 180 impacted power lines and a chain link fence during a forced landing adjacent to LMO. The flight instructor and private pilot receiving instruction on-board the Cessna 172 were fatally injured. The pilot of the Cessna 180 sustained minor injuries. The Cessna 172 was registered to MountainAir Aviation Services LLC and operated by McAir Aviation LLC under the provisions of 14 Code of Federal Regulations Part 91 as an instructional flight. The Cessna 180 was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flights, which were both operated without flight plans. The Cessna 172 departed Rocky Mountain Metropolitan Airport (BJC) about 1130. The Cessna 180 departed Erie Municipal Airport (EIK) about 1136.

At 1130, the Cessna 172 was issued a takeoff clearance by the BJC air traffic control tower. At 1132, an aircraft on a 1200 transponder beacon code [the standard code for visual flight rules (VFR) operations] was observed on Denver Terminal Radar Approach Control (TRACON) facility radar in the vicinity of BJC. Based on the subsequent course flown, this aircraft is presumed to be the Cessna 172 airplane. The radar track data indicated that the airplane initially proceeded on a northwest course from BJC, before turning to a north-northeast course. About 11 miles north of BJC, the airplane executed a left 360-degree turn and returned to a north-northeast course. The track data depicted the airplane converging with a second target about 0.5 miles south of the Cessna 172 accident site.

At 1136, an aircraft on a 1200 (VFR) transponder beacon code was observed on Denver TRACON facility radar in the vicinity of EIK. Based on the subsequent course flown, this aircraft is presumed to be the Cessna 180 airplane. The radar data indicated that the airplane departed to the south and executed a right 180-degree turn to a northwest course. The airplane subsequently turned right to a north-northeast course.

The radar track data depicted the flight paths slowly converging to a point about 0.5 miles south of the Cessna 172 accident site. The data indicated that the Cessna 172 was at 7,200 feet mean sea level (msl), while the Cessna 180 was in a slow climb from 6,800 feet to 7,000 feet msl. At 1142:28 (hhmm:ss), the airplanes were separated laterally by about 393 feet and vertically by about 200 feet. A loss of potentially two radar data points corresponding to the Cessna 180 was observed between 1142:29 and 1142:41. The loss of the data points is consistent with the close proximity to the second airplane at the t