Narrative:

I was practicing touch-and-go's in the pattern at unv. Prior to flight; a briefing was obtained from duats; and no weather issues were apparent. Winds were light. A preflight inspection of the aircraft did not identify any issues; and the run up and taxi to runway 24 were unremarkable. Four approaches were performed; three of which were touch-and-go and the other was a practice go-around. All three landings were normal. While accelerating for the fifth takeoff; all appeared normal; and when the aircraft was close to rotation speed it suddenly deviated to the left of the centerline; pointing towards the left edge of the runway; and an attempt to correct with right rudder suggested to me that I would not be able to get back on the centerline without significant rudder input and further loss of control. The airplane became airborne after rolling into the grass off the left side of the runway near the 2;000-foot marker. After achieving a positive rate of climb; I immediately communicated with unv tower indicating that I was ok and that I wasn't sure if there was an unexpected wind on the runway or something else had happened. I entered a left downwind for runway 24; and did a check on the rudders and other flight controls; and concluded that everything was fine. I landed normally on runway 24; requested a taxi back to the hangars; and the taxi procedure appeared normal. Upon returning to the hangar; I did a full inspection of the airplane and did not notice anything unusual except for a few tufts of grass on the left and right brakes. Several days later; another pilot noted dents to the underside of the tail; on the passenger's side. Discussions with others including flight instructors failed to conclusively identify the issue that led to this event; but perhaps it was caused by a temporary lapse of attention in which deviation of the airplane from the centerline was not noticed until it was too difficult to recover. It is believed the damaged tail was caused by striking a runway light.

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Original NASA ASRS Text

Title: C172 pilot reported loss of directional control on takeoff roll. Control was regained after liftoff.

Narrative: I was practicing touch-and-go's in the pattern at UNV. Prior to flight; a briefing was obtained from DUATS; and no weather issues were apparent. Winds were light. A preflight inspection of the aircraft did not identify any issues; and the run up and taxi to Runway 24 were unremarkable. Four approaches were performed; three of which were touch-and-go and the other was a practice go-around. All three landings were normal. While accelerating for the fifth takeoff; all appeared normal; and when the aircraft was close to rotation speed it suddenly deviated to the left of the centerline; pointing towards the left edge of the runway; and an attempt to correct with right rudder suggested to me that I would not be able to get back on the centerline without significant rudder input and further loss of control. The airplane became airborne after rolling into the grass off the left side of the runway near the 2;000-foot marker. After achieving a positive rate of climb; I immediately communicated with UNV Tower indicating that I was OK and that I wasn't sure if there was an unexpected wind on the runway or something else had happened. I entered a left downwind for Runway 24; and did a check on the rudders and other flight controls; and concluded that everything was fine. I landed normally on runway 24; requested a taxi back to the hangars; and the taxi procedure appeared normal. Upon returning to the hangar; I did a full inspection of the airplane and did not notice anything unusual except for a few tufts of grass on the left and right brakes. Several days later; another pilot noted dents to the underside of the tail; on the passenger's side. Discussions with others including flight instructors failed to conclusively identify the issue that led to this event; but perhaps it was caused by a temporary lapse of attention in which deviation of the airplane from the centerline was not noticed until it was too difficult to recover. It is believed the damaged tail was caused by striking a runway light.

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.