Investigation Summary
The collision occurred at approximately 1,450 feet MSL in visual meteorological conditions. The F-16 pilot was in contact with Charleston Approach, while the Cessna pilot was monitoring the local Common Traffic Advisory Frequency (CTAF) and was not in communication with ATC. A conflict alert triggered on the controller's display when the aircraft were 3.5 nautical miles apart. The controller issued a traffic advisory to the F-16 and then a conditional instruction to turn left to a heading of 180 degrees if the traffic was not in sight. The F-16 pilot was confused by the radar target distance because his tactical radar had detected a target 20 miles away, leading him to question the controller's advisory of traffic at 2 miles. This confusion, combined with the high closure rate of approximately 300 knots, resulted in the F-16 striking the Cessna broadside. The NTSB noted that the controller's instruction to turn left was the 'least conservative' option as it required the F-16 to cross the Cessna's path. Furthermore, the controller expected a high-performance maneuver when using the word 'immediately,' but the pilot executed a standard rate turn using the autopilot.
Final Conclusions
The NTSB determined the probable cause was the approach controller's failure to provide an appropriate resolution to the conflict. Contributing factors included the inherent limitations of the see-and-avoid concept, which prevented both pilots from taking timely evasive action. The Air Force Accident Investigation Board also cited the controller's direction and the pilots' inability to see and avoid each other as primary causes.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Private N3601V — Cessna 150M · N3601V
United States Air Force USAF 96-0085 — Lockheed Martin F-16CM · 96-0085
Systems & Failure Modes
Conflict Alert (CA)
An ATC radar processing function that generates an alert when the predicted proximity of two aircraft falls below defined separation minima.
APG-68 Radar
The F-16's tactical radar, which in this instance detected a target 20 miles away but struggled to track the slow-moving Cessna at close range.
See-and-Avoid
The primary method of collision avoidance in VFR conditions, which was limited here by high closure speeds and cockpit visibility obstructions.
Interesting Facts
- 01The F-16's tactical radar was designed for fast-moving targets and failed to effectively detect the slow-moving Cessna.
- 02The closure rate between the two aircraft was approximately 300 knots.
- 03The Cessna was not equipped with a Traffic Advisory System (TAS) or TCAS.
- 04The F-16 pilot only visually acquired the Cessna one second before the collision.
- 05The controller's use of the word 'immediately' was intended to prompt a high-performance turn, but the pilot used the autopilot for a standard rate turn.
Safety Actions & Advisories
ATC Training Briefings
The NTSB recommended briefing all air traffic controllers on the errors of this collision to improve judgment and safety awareness.
Safety Alert SA-058
The NTSB issued a safety alert titled 'Prevent Midair Collisions: Don't Depend on Vision Alone' to encourage the use of traffic display technologies.
Airport Chart Updates
Berkeley County Airport updated its chart supplement to warn pilots of heavy military traffic arriving at Joint Base Charleston.