Challenger 605 flight crew reported an upset event during climb. The pilot flying immediately disconnected the autopilot and autothrottles and worked with the pilot monitoring to regain aircraft control. The flight crew elected to perform an air turn back to departure airport.
Synopsis
Challenger 605 flight crew reported an upset event during climb. The pilot flying immediately disconnected the autopilot and autothrottles and worked with the pilot monitoring to regain aircraft control. The flight crew elected to perform an air turn back to departure airport.
Narrative
I was the pilot in command (PIC) / pilot monitoring (PM) and the second in command (SIC) was pilot flying (PF). About 2;800 ft. climbing to 3;000 ft.; with Autopilot engaged; auto throttle engaged; vertical speed engaged about 400 foot climb and heading mode; the aircraft radically pitched nose up approximately 15-17 degrees. The stick pusher engaged and pushed the nose approximately 12 degrees down. The Autopilot disconnected and the SIC disconnected the autothrottle to regain control from the upset.Aircraft was now under control at approximately 3;500 ft. ATC queried as to what our altitude was. PIC reported that we had an upset event and told ATC to standby and we would get back to him as the PIC was focused on evaluating and making sure the aircraft was under control. ATC then told us to climb to 4;000 ft. which we complied with. ATC further asked if we needed help with which PIC said everything is now normal and we were then given a climb to 14;000 ft.Autopilot and autothrottles were reengaged and being guarded in case of another upset.PIC requested a return back to ZZZ. ATC asked if we were [requesting priority handling] but since everything was now back under control and normal; we replied no.Rest of flight was uneventful.
Second reporter narrative
As the second in command (SIC) I was the pilot flying and during climb to the departure pre-selected altitude of 3;000 ft. with the autopilot and autothrottles engaged at about 2;800 ft. the aircraft pitched violently to an unusual nose up attitude and it seemed like simultaneously the stick pusher activated and the Autopilot disconnected in a similar violent fashion.I instinctively turned off the auto throttles and pushed the Autopilot disconnect switch to silence the aural warning; while positively exerting inputs to regain aircraft control.ATC inquired if we were having any issues as he noticed our altitude fluctuating from up to down several hundred feet.The pilot in command (PIC) responded we were having an event and we were trying to sort the problem and we would get right back to him. ATC inquired if we needed assistance and the PIC responded not at this time and we would get back to him. When I regained aircraft control we leveled off at 3;500 ft. and then ATC cleared us to 4;000 ft. and then to 14;000 ft. and we complied. During our subsequent climb in conferring as a crew we concluded in the interest of safety and in conformance with company policy and good sound judgement the best course of action was to return to ZZZ. I continued to fly the airplane and proceeded to a safe uneventful landing at the departure airport at ZZZ.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.