G280 flight crew reported the aircraft abruptly pitched up while on autopilot and the flight crew stopped the climb and executed an air turnback.
Synopsis
G280 flight crew reported the aircraft abruptly pitched up while on autopilot and the flight crew stopped the climb and executed an air turnback.
Narrative
On Day 0 at XA:38; Aircraft X departed ZZZ for ZZZ1. There were 7 passengers and 3 crewmembers onboard. Weather was greater than 10 miles visibility and clear skies. Upon climbing through 10000 feet; the autopilot (AP) was turned on; and we continued the climb to FL210. At approximately 15000 feet; the airplane abruptly pitched up and the AP turned off. The crew stopped the climb and asked to return to ZZZ to further troubleshoot. The AP was not turned back on and the crew came in for an approach to [Runway] XXL and landed with no further issues. The passengers disembarked and flew home commercially; as Gulfstream was called to assist with the troubleshooting. Four hours later; we learned from one of the passengers that two of the passengers had hit their heads during the event. One passenger mentioned having a bump on her head and not feeling right." The other passenger reports having soreness on his head and neck; and that he napped on the plane which is very strange for him. He also says that he feels "out of it." They are both planning on going to the doctor once they arrive in ZZZ1; but that they are starting to feel better. All other passengers report no injuries."
Second reporter narrative
[Report narrative contained no additional information.]
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.