MD80 SUFFERS APPARENT ROLL CTL ANOMALY IN R-HAND TURNS AFTER AUTOPLT DISCONNECT. NO OTHER INDICATIONS AND RESPONSE RETURNED TO NORMAL DURING APCH.

Narrative

TAXI OUT RNAV DEP; AUTOPLT ON APPROX 12000 FT. ON CLBOUT; AUTOPLT DISCONNECTED. CTL COLUMN FELT HEAVIER THAN NORMAL. REGARDING AILERONS; NOTED DIFFICULTY COMMANDING R BANK. TRIMMED ACFT AT CRUISE -- AUTOPLT WORKED PERFECTLY REMAINDER OF FLT. NO EXCESS TRIM NOTED; AILERON TRIM MOVED FREE. AILERON AND RUDDER TRIM APPROX ON MAIN INDEX CTRED. DISCUSSED POSSIBILITIES; QRH; MAINT; DISPATCH. KEPT ALL INFORMED OF INTENTIONS. BRIEFED FLT ATTENDANTS AND PAX OF SIT. COULD NOT DETERMINE MAGNITUDE OF UNCTLABILITY UNTIL LOWER AND BETTER INDICATED AIRSPD. DURING DSCNT; TOOK AUTOPLT OFF FOR BETTER DETERMINATION OF CTL DEFICIENCY. STILL FELT 'HVY' AND HARDER TO TURN IN ONE DIRECTION. INFORMED ATC AND DECLARED EMER. REQUESTED DIRECT ZZZ FOR 25 MI FINAL TO CONFIGURE EARLY TO DETERMINE FULLY ACFT CAPABILITY. REQUESTED CFR. CONSIDERED XWINDS AND RWY LENGTH. ACFT REGAINED FULL CTLABILITY AT ABOUT 150 FT AGL. LANDED AND PROCEEDED TO GATE WITHOUT INCIDENT. SUBSEQUENTLY; MAINT 'STICKED' THE FUEL TANKS AND FOUND WE HAD APPROX 3100 LBS PER TANK RATHER THAN THE 5000 LBS PER TANK INDICATING ON FUEL PANEL. TESTED BOTH CHANNEL A AND B FOR QUANTITY READING AND TOTALIZER CHK. FUEL QUANTITY SYS IN COCKPIT OPERATED NORMAL DURING THESE CHKS.