Narrative:

Flight from phx-tus. During takeoff roll in a boeing 737-300 at phx, just prior to V1 (139 KTS), a sharp momentary yaw left occurred with a jolt. Our takeoff was continued and the 'yaw damper non-normal checklist' was complied with. Yaw damper switch was turned to off position. The 'after takeoff checklist' was then complied with as our departure continued. After leveloff at 17000 ft MSL, an evaluation of situation was discussed between cockpit crew. Then maintenance was notified and the discrepancy was entered into the logbook. Quote, 'during takeoff roll at phx just prior to V1 (139 KTS), a sharp, momentary yaw left occurred. Takeoff continued and yaw damper was turned off.' the flight landed in tus with no further occurrences.

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Original NASA ASRS Text

Title: SUDDEN YAW DURING TKOF.

Narrative: FLT FROM PHX-TUS. DURING TKOF ROLL IN A BOEING 737-300 AT PHX, JUST PRIOR TO V1 (139 KTS), A SHARP MOMENTARY YAW L OCCURRED WITH A JOLT. OUR TKOF WAS CONTINUED AND THE 'YAW DAMPER NON-NORMAL CHKLIST' WAS COMPLIED WITH. YAW DAMPER SWITCH WAS TURNED TO OFF POS. THE 'AFTER TKOF CHKLIST' WAS THEN COMPLIED WITH AS OUR DEP CONTINUED. AFTER LEVELOFF AT 17000 FT MSL, AN EVALUATION OF SIT WAS DISCUSSED BTWN COCKPIT CREW. THEN MAINT WAS NOTIFIED AND THE DISCREPANCY WAS ENTERED INTO THE LOGBOOK. QUOTE, 'DURING TKOF ROLL AT PHX JUST PRIOR TO V1 (139 KTS), A SHARP, MOMENTARY YAW L OCCURRED. TKOF CONTINUED AND YAW DAMPER WAS TURNED OFF.' THE FLT LANDED IN TUS WITH NO FURTHER OCCURRENCES.

Data retrieved from NASA's ASRS site as of July 2007 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.