Narrative:

Normal rotation to 300 ft following commands on flight director. While hand flying the departure; I notice that the aircraft is not properly autotrimming and holding my desired flight path. The aircraft slowly but deliberately pitched upward while the stab trim added nose up trim. This increased the rate of nose up. I had to hold slight nose down pressure on the sidestick to achieve my desired flight path of following the flight director commands. Autothrust was engaged and operating normally. This condition was present with takeoff configuration flaps and in clean configuration as well. We never exceeded 250 KIAS. The captain took controls to feel what I was describing and he agreed with my assessment. The captain and I decided to return to ZZZ. We never lost control or questioned the safe outcome of the flight; but we both felt something was not right. No emergency was declared. We received vectors to a visual approach. The autopilot was never engaged. We touched down at 171;800 pounds. That put us overweight by approximately 400 pounds. We detailed our experience to 3 maintenance techs and wrote up the flight control issue and overweight landing in the logbook. In retrospect we probably should have declared an emergency with ATC due to the nature of the problem being flight control. No failure messages or obvious malfunctions were detected or observed during or after the 16 minute flight.

Related reports:

Google
 

Original NASA ASRS Text

Title: A321 First Officer reported that while hand flying the departure; the autotrim system continued to pitch the aircraft nose up. The flight returned to the departure airport.

Narrative: Normal rotation to 300 ft following commands on flight director. While hand flying the departure; I notice that the aircraft is not properly autotrimming and holding my desired flight path. The aircraft slowly but deliberately pitched upward while the stab trim added nose up trim. This increased the rate of nose up. I had to hold slight nose down pressure on the sidestick to achieve my desired flight path of following the flight director commands. Autothrust was engaged and operating normally. This condition was present with takeoff configuration flaps and in clean configuration as well. We never exceeded 250 KIAS. The captain took controls to feel what I was describing and he agreed with my assessment. The captain and I decided to return to ZZZ. We never lost control or questioned the safe outcome of the flight; but we both felt something was not right. No emergency was declared. We received vectors to a visual approach. The autopilot was never engaged. We touched down at 171;800 pounds. That put us overweight by approximately 400 pounds. We detailed our experience to 3 maintenance techs and wrote up the flight control issue and overweight landing in the logbook. In retrospect we probably should have declared an emergency with ATC due to the nature of the problem being flight control. No failure messages or obvious malfunctions were detected or observed during or after the 16 minute flight.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.