Background
Two Cessna aircraft, a Cessna 182Q and a Cessna 172RG, were operating in Class D airspace and had departed from the same airport. The Cessna 172RG was conducting an instructional flight under instrument flight rules (IFR) and receiving radar services from an approach control facility. The Cessna 182Q was operating under visual flight rules (VFR) and had been released from communication with air traffic control. The pilot undergoing instruction in the Cessna 172RG was most likely wearing a view limiting device, requiring the certified flight instructor in the right seat to serve as both instructor and safety pilot.
Events Leading to Collision
The Cessna 172RG departed first, executing a right 260-degree turn over the airport and was assigned a southwest heading by the controller. The Cessna 182Q departed to the west, made a left turn, and climbed in a southeasterly direction. The heading assigned to the Cessna 172RG placed it on a direct collision course with the Cessna 182Q, with a collision angle of 40 degrees.
Communication and Conflict Alert
After discussing the pilot's intentions upon completion of an approach, the controller instructed the Cessna 172RG to fly heading 190. The pilot read back "One nine" and no further transmissions were received from that aircraft. In Class D airspace, there is no specified separation requirement between VFR and IFR aircraft, but controllers have a responsibility to be vigilant for potential collisions. Controllers in communication with the Cessna 172RG had received a sustained conflict alert involving both aircraft; the Cessna 182Q was operating on a VFR transponder code. The controllers failed to recognize or resolve the conflict.
Pilot Visibility Considerations
Comparison of calculated convergence angles of the two airplanes indicated visibility limitations. For an 85th percentile male seated in the left seat—and noting that Cessna did not provide pilot view angles for the front right seat—the Cessna 172RG pilot was about 15 degrees outside the right view angle, while the Cessna 182Q pilot was within about 6 degrees of the left view angle.