LR45 captain reported encountering a stabilizer trim malfunction.

Attributes
ACN	1646086
Time
Date	201905
Local Time Of Day	0601-1200
Place
Locale Reference	IAD.Airport
State Reference	DC
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Learjet 45
Operating Under FAR Part	Part 91
Flight Phase	Final Approach
Route In Use	Visual Approach
Flight Plan	IFR
Component
Aircraft Component	Horizontal Stabilizer Trim
Person 1
Function	Captain
Qualification	Flight Crew Multiengine Flight Crew Instrument Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Instructor
Experience	Flight Crew Last 90 Days 75 Flight Crew Total 3600 Flight Crew Type 600
Events
Anomaly	Aircraft Equipment Problem Critical Deviation - Procedural Published Material / Policy

Narrative:

During approach; abnormal control forces were noted while trimming the aircraft for landing configuration. Horizontal stabilizer was not moving in the primary trim switch position. Crew elected to switch to secondary trim; no horizontal stabilizer motion was detected. We chose to go on a missed approach to run the appropriate QRH checklist; after switching back to primary trim; PIC tried once more to move the trim position and noted small movement; but at a reduced rate. Aircraft was then configured for landing and a normal approach and landing was successfully made. Once parked at the FBO; trim system functional check was completed; no abnormalities were noted. Aircraft was grounded for maintenance personnel to perform an inspection on the horizontal stab system.

Original NASA ASRS Text

Title: LR45 Captain reported encountering a Stabilizer Trim malfunction.

Narrative: During approach; abnormal control forces were noted while trimming the aircraft for landing configuration. Horizontal stabilizer was not moving in the primary trim switch position. Crew elected to switch to secondary trim; no horizontal stabilizer motion was detected. We chose to go on a missed approach to run the appropriate QRH checklist; after switching back to primary trim; PIC tried once more to move the trim position and noted small movement; but at a reduced rate. Aircraft was then configured for landing and a normal approach and landing was successfully made. Once parked at the FBO; trim system functional check was completed; no abnormalities were noted. Aircraft was grounded for maintenance personnel to perform an inspection on the horizontal stab system.

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.