What was found
FLT 7972 - EWR - DURING CRUISE, PITCH BECAME STIFF WHEN PULLING ON YOKE. A FEW DEGREES OF TRAVEL IT WOULD SEEM FINE, AFTER THAT IT WAS STIFF. MAINTENANCE PERFORMED A DETAILED VISUAL INSPECTION OF THE ELEVATOR CONTROL SYSTEM, ELEVATOR SURFACES, TRIM TABS, AND SPRING TABS. NO DEFECTS NOTED. ELEVATOR SURFACE MOVED FREELY DURING GROUND OPERATION CHECK. NO DEFECTS NOTED.