HAZARD REPORT OF, ATC: Unreported weather balloon in W-386/NAS Patuxent River offshore Test Track

On February 13, 2019, at 1635 local time, a flight test event involving four aircraft from Air Test and Evaluation Squadron 23 (VX-23) was conducted in the W-386/NAS Patuxent River offshore test track. During the execution of tactical intercept maneuvers, aircrew visually identified a red weather balloon at an altitude of 27,000 feet MSL. Upon querying the relevant control authorities, specifically Giant Killer and Echo control, it was determined that neither agency had been notified of any weather balloon activity in the area. Furthermore, a review of Notices to Airmen (NOTAMs) confirmed that no such activity had been authorized or announced. The report notes that multiple other radar contacts were observed in the vicinity, exhibiting similar altitudes and speeds ranging from 0.1 to 0.2 indicated Mach number (IMN). Several ships were also operating in the area at the time. The investigation concluded that the hazard was the result of an unknown agency releasing a weather balloon without following proper notification procedures. The report highlights a failure to effectively communicate the release to the appropriate channels. As a corrective measure, the squadron recommended that all aircrew be briefed on the incident. The report emphasizes that weather balloons frequently appear identical to spurious radar contacts and advises aircrew to maintain situational awareness, treating all radar contacts as actual objects until they are proven otherwise.