Narrative:

The weather was VFR and there were no significant issues at all. After the before taxi checklist; we taxied out for departure in a B737-300. The wait time was minimal. Cleared for takeoff and it was my leg (captain). At 60 KTS; I noticed the control wheel moving back and forth like it does when there is turbulence in flight. It wasn't radical; but noticeable. All other indications were normal and remember; there were no weather issues. At 80 KTS; my hand came off the tiller and onto the control wheel. I could now feel the wheel moving in my hand. It was still nothing radical but I could feel it moving. Thinking it may just a little wind; we continued. Around 100 KTS the speed trim wheel started moving slowly. I looked up on the panel to confirm the hydraulic pump position and they were all on; the standby pump was off. All indications were still normal. V1 was called by the first officer and I pulled back on the wheel with normal back pressure. At this point; the controls felt like they do when you turn the hydraulic pumps off. I can't remember at what point this happened but the nose wheel was definitely off the ground when I yanked hard on the wheel to get the aircraft airborne. As I did; the autopilot kicked off. (We did not turn it on.) once the autopilot kicked off; the controls were normal again. I was confused as to what was happening on the takeoff roll as there were no windshear reports. We never touched the autopilot at all and we completed all checklists as required including the flight control check. Very near V1 and even after V1; the thought of a rejected takeoff was clearly on my mind but I could not figure out what was happening until after the nose wheel was in the air. The flight continued normally. The autopilot worked just fine. There were absolutely no other abnormal indications. I now ensure that the flight control check is completed stop to stop before we take the runway even though we did it before taxi out.

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Original NASA ASRS Text

Title: B737-300 Captain reports the control wheel rolling gently left and right during the takeoff roll. At V1 considerable resistance is noted while trying to rotate. More force is applied and the aircraft rotates normally accompanied by the sound of the autopilot disengaging.

Narrative: The weather was VFR and there were no significant issues at all. After the Before Taxi Checklist; we taxied out for departure in a B737-300. The wait time was minimal. Cleared for takeoff and it was my leg (Captain). At 60 KTS; I noticed the control wheel moving back and forth like it does when there is turbulence in flight. It wasn't radical; but noticeable. All other indications were normal and remember; there were no weather issues. At 80 KTS; my hand came off the tiller and onto the control wheel. I could now feel the wheel moving in my hand. It was still nothing radical but I could feel it moving. Thinking it may just a little wind; we continued. Around 100 KTS the speed trim wheel started moving slowly. I looked up on the panel to confirm the hydraulic pump position and they were all on; the standby pump was off. All indications were still normal. V1 was called by the First Officer and I pulled back on the wheel with normal back pressure. At this point; the controls felt like they do when you turn the hydraulic pumps off. I can't remember at what point this happened but the nose wheel was definitely off the ground when I yanked hard on the wheel to get the aircraft airborne. As I did; the autopilot kicked off. (We did not turn it on.) Once the autopilot kicked off; the controls were normal again. I was confused as to what was happening on the takeoff roll as there were no windshear reports. We never touched the autopilot at all and we completed all checklists as required including the flight control check. Very near V1 and even after V1; the thought of a rejected takeoff was clearly on my mind but I could not figure out what was happening until after the nose wheel was in the air. The flight continued normally. The autopilot worked just fine. There were absolutely no other abnormal indications. I now ensure that the flight control check is completed stop to stop before we take the runway even though we did it before taxi out.

Data retrieved from NASA's ASRS site as of April 2012 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.