Mooney M20R N57GX and Cessna R172K N758PK incident near Jacksonville, Florida

Probable cause

The air traffic controller's decision to issue climb instruction to one aircraft without ensuring the required separation with another could be maintained. Contributing to the incident was the air traffic controller's failure to issue a safety alert in a timely manner.

NTSB analysis

The loss of separation occurred after the air traffic controller issued N57GX a climb from 5,000 feet to 9,000 feet while N758PK was on an opposite direction heading, level at 8,000 feet. The air traffic controller became aware of the incident after the pilot of N57GX reported that he had received a conflict alert and had taken evasive action to avoid a collision with N785PK.

After N57GX had departed OCF, the air traffic controller instructed the pilot to climb to 5,000 feet, and subsequently issued the pilot a climb to 9,000 feet, which was the pilot's requested altitude. The air traffic controller did not consider the performance of the aircraft, or the proximity of N785PK when he issued the climb instructions to N57GX. The decision by the air traffic controller to climb N57GX without ensuring minimum radar or vertical separation would exist, and be maintained, resulted in the aircraft coming into close proximity to one another. Additionally, the controller did not issue a safety alert when the air traffic control conflict alert activated, requiring the pilot of N57GX to take evasive action to avoid a collision with N758PK. The closest proximity was estimated to be 0.85 nautical miles lateral and 200 feet vertical separation.

Text from the NTSB. Open the NTSB docket for OPS16IA010 for the full record.