The FAA confirmed to AIN that a Gulfstream G550 experienced a midair collision with a mysterious object at FL270 in Miami airspace on December 11 during a flight from Fort Lauderdale Executive Airport (KFXE) to New York’s Westchester County Airport (KHPN). According to the FAA statement, the twinjet diverted to, and landed safely at, Palm Beach International Airport (KPBI) “after the pilot reported striking an object in Miami airspace.”

Little information is available publicly about the incident, other than an entry on Flight Safety Foundation’s Aviation Safety Network website and a post on social media platform X by Ryan Graves, co-founder and executive director of Americans for Safe Aerospace, a website and nonprofit organization for reporting unidentified anomalous phenomena (UAP). According to Graves’ post, one of the G550’s engines failed after the encounter with “an unidentified metallic object…at approximately 27,000 feet.”

Graves describes the reporter, who is not one of the G550’s pilots, as a whistleblower. “The whistleblower is concerned because this altitude is highly regulated Class A airspace that requires flight plans and transponders, but in this instance, there were no flight plans for the object and the object was not squawking a transponder code.

“We can largely eliminate the possibility of common objects because: a weather balloon would have been transponding; this altitude is too high for hobby drones and illegal for any drone; there is no biological indicator of a bird strike; [and] video of the engine shows metal damage.”

Graves, a former Navy lieutenant and F/A-18F pilot, wrote, “I am concerned the incident is being downplayed by FAA. The report is being classified as an ‘incident’ and not an ‘accident,’ which would require public announcement, investigation by NTSB, and an explanation.”

An accident or serious incident must be reported to the NTSB, but in this case it’s not clear whether this was reported or that it was required. An accident is defined as a situation in which “any person suffers death or serious injury, or in which the aircraft receives substantial damage.” The “serious incident” list doesn’t include failure of one engine on a transport-category airplane or collision with a UAP, unless, according to the NTSB, there is “failure of any internal turbine engine component that results in the escape of debris other than out the exhaust path.”

As to whether a balloon and its payload could have been the UAP, not all balloons are transponder-equipped, according to the FAA: “Some operators have equipped their balloons with transponder beacons in addition to a radar reflection device or material required by 14 CFR Section 101.35, but at cruise altitude, the balloon's communications equipment and transponder, if so equipped, are operated intermittently to conserve battery energy.”

Although the FAA declined to answer AIN’s question about whether it planned to investigate the G550 engine failure, it may be likely because FAA Part 21 regulations (21.3(c)(10)) require the aircraft’s type certificate holder to report an engine failure.