Narrative:

After 4 hour sit; tail swapped into [another aircraft] due to cargo door issue on original aircraft. At first we were told by maintenance that this aircraft was unavailable as it was scheduled for maintenance for recurring 'flight control; slat; trim issues'. Cargo and crew then switched to this aircraft and advised it was green. En route portion of flight was uneventful. Upon final approach and fully configured with first officer flying a visual autopilot off VMC approach. At approximately 2;000 ft AGL aircraft suddenly pitched up to approximately 10 degrees; after slight delay throttles advanced to maintain bugged speed at 120 KTS. I then asked first officer what he was doing. He then stated it wasn't him and at that time I instructed him to turn off all flight control automation. First officer confirmed all automation was off; which I verified. I then commanded he discontinue the landing. At that time aircraft was climbing to approximately 2;500 ft. I then joined the first officer on the yoke and applied full locked arm pressure. First officer then retarded throttles and we were able to level the aircraft at 3;000 ft. First officer continued to fly the aircraft at 210 KTS; 3;000 ft. I then declared an emergency and we cleaned up the aircraft. We then maintained 3;000 ft and ensured basic control of the aircraft. Trim then seemed to be operating normal. We then reconnected the auto throttle and then the autopilot and flew a hand flown ILS. Once configured at 2;000 ft for landing stab trim was not used by the first officer. Aircraft landed without further incident. In review it felt as if this situation was a run away nose up stab trim.

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Original NASA ASRS Text

Title: B757 flight crew reports accepting an aircraft with a history of trim issues; but are assured by Maintenance that the aircraft is good to go. During approach the aircraft abruptly pitches up and the First Officer has difficulty maintaining control. With the Captain's help the aircraft is returned to level flight and in trim. The next approach and landing is uneventful.

Narrative: After 4 hour sit; tail swapped into [another aircraft] due to cargo door issue on original aircraft. At first we were told by Maintenance that this aircraft was unavailable as it was scheduled for maintenance for recurring 'flight control; slat; trim issues'. Cargo and crew then switched to this aircraft and advised it was green. En route portion of flight was uneventful. Upon final approach and fully configured with First Officer flying a visual autopilot off VMC approach. At approximately 2;000 FT AGL aircraft suddenly pitched up to approximately 10 degrees; after slight delay throttles advanced to maintain bugged speed at 120 KTS. I then asked First Officer what he was doing. He then stated it wasn't him and at that time I instructed him to turn off all flight control automation. First Officer confirmed all automation was off; which I verified. I then commanded he discontinue the landing. At that time aircraft was climbing to approximately 2;500 FT. I then joined the First Officer on the yoke and applied full locked arm pressure. First Officer then retarded throttles and we were able to level the aircraft at 3;000 FT. First Officer continued to fly the aircraft at 210 KTS; 3;000 FT. I then declared an emergency and we cleaned up the aircraft. We then maintained 3;000 FT and ensured basic control of the aircraft. Trim then seemed to be operating normal. We then reconnected the auto throttle and then the autopilot and flew a hand flown ILS. Once configured at 2;000 FT for landing stab trim was not used by the First Officer. Aircraft landed without further incident. In review it felt as if this situation was a run away nose up stab trim.

Data retrieved from NASA's ASRS site as of July 2013 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.