B737 Next Generation Undifferentiated
Flight Crew Air Transport Pilot (ATP)
Flight Crew Type 7437
Aircraft Equipment Problem Less Severe
Air Traffic Control Issued New Clearance; Flight Crew Diverted; Flight Crew Landed As Precaution; Flight Crew Requested ATC Assistance / Clarification
Aircraft
Normal departure until cleaning up the flaps and slats. After everything was up; got master caution; flight controls; speed trim fail lights. At the same time the aircraft started slow trimming nose up. I was able to counter the movement with the trim switch on the yoke. Kept the speed at 250 and continued the departure so that we could run the non-normal checklist. After turning off the two guarded trim switches below and to the right of the throttles; the runaway condition stopped. Down to manual trim. We [advised ATC] and ATC leveled us off at FL240 and turned us back to [an alternate airport] per our request to divert there. Contacted the Company; briefed the Flight Attendants and passengers. Made a smooth; uneventful overweight landing.
[Report narrative contained no additional information.]
B737 flight crew reported diverting to an alternate airport after experiencing a stabilizer trim runaway.