B737 flight crew reported nose down trim inoperative on initial climb out.

Attributes
ACN	1612303
Time
Date	201901
Place
Locale Reference	ZZZ.Airport
State Reference	US
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Initial Climb
Flight Plan	IFR
Component
Aircraft Component	Elevator Trim System
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Multiengine Flight Crew Instrument Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 180 Flight Crew Type 22000
Person 2
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Multiengine Flight Crew Instrument Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Less Severe

Narrative:

On initial climb out off of runway xx ZZZ; we experienced the aircraft pitching up without the autopilot engaged at approximately 4500 feet. I tried using the down trim and it was not working; I immediately pushed forward on the yoke and manually trimmed the aircraft back into trim. We notified ATC we needed to level off at 6000 feet. We assessed the situation and ran the appropriate checklist. While doing this we advised ATC we needed to return to ZZZ and [coordinated with ATC]. We were vectored for a downwind leg for runway 23. The approach was briefed; [performance data calculated] with non-normal and brake cooling checked; dispatch notified and QRH checklist completed. We made a flaps 15 landing with no further issues.

Original NASA ASRS Text

Title: B737 flight crew reported nose down trim inoperative on initial climb out.

Narrative: On initial climb out off of Runway XX ZZZ; we experienced the aircraft pitching up without the autopilot engaged at approximately 4500 feet. I tried using the down trim and it was not working; I immediately pushed forward on the yoke and manually trimmed the aircraft back into trim. We notified ATC we needed to level off at 6000 feet. We assessed the situation and ran the appropriate checklist. While doing this we advised ATC we needed to return to ZZZ and [coordinated with ATC]. We were vectored for a downwind leg for Runway 23. The approach was briefed; [performance data calculated] with non-normal and brake cooling checked; Dispatch notified and QRH Checklist completed. We made a flaps 15 landing with no further issues.

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.