B737 FLC EXPERIENCE A WING FLAP INDICATION PROB ON APCH TO ORD AND ARE ABLE TO RESOLVE SIT AFTER VERIFYING ALTERNATE EXTENSION PROC WITH MAINT.

Narrative

ABOUT 1 HR PRIOR TO LNDG AT FL350; THE R FLAP INDICATOR NEEDLE FELL TO THE 8 O'CLOCK POS. THE L NEEDLE REMAINED AT THE 9 O'CLOCK (UP) POS. ABOUT TEN MINUTES LATER; THE R NEEDLE SNAPPED BACK TO THE 9 O'CLOCK (UP) POS. WE BEGAN OUR DSCNT INTO ORD AND AROUND BEARZ; THE R NEEDLE DROPPED AGAIN TO THE 8 O'CLOCK POS. IT STAYED THERE FOR A FEW MINS AND THEN CORRECTED ITSELF AGAIN. WE WERE CONCERNED ABOUT ASYMMETRY PROTECTION WHEN WE WENT TO LOWER THE FLAPS FOR THE APCH. THE CAPT DECIDED TO CALL MAINT. HE GAVE THE ACFT AND THE RADIOS TO ME. HE CONTACTED MAINT AND THEY LOOKED UP THE ALTERNATE FLAP EXTENSION PROC. HE EXPLAINED HIS CONCERNS TO MAINT. THEY BOTH AGREED THE BEST ACTION WAS TO FOLLOW THE ALTERNATE FLAP PROC. WE BOTH REVIEWED THE PROC; INCLUDING GAR. THE CAPT TOOK THE ACFT BACK AND I ACCOMPLISHED THE CHKLISTS. WE FLEW NORMAL APCH TO RWY 27L. PASSING 1500 FT AGL; TWR CLRED AN ACR Y B727 FOR TKOF ON RWY 22L. PASSING 500 FT; THE B727 WAS IN POS BUT NOT ROLLING. AT 200 FT; TWR ISSUED GAR BECAUSE OF TRAVEL TIME FOR FLAPS IN ALTERNATE MODE. WE LEFT THE GEAR AND FLAPS (15 DEGS) DOWN AND CLBED TO 5000 FT FOR A DOWNWIND VECTOR BACK TO RWY 27L. WE WERE VISUAL AND HOPED FOR A TIGHT APCH. WE BEGAN THE APCH AND LANDED NORMALLY. THE ALTERNATE FLAP CHKLIST DOES NOT ADDRESS AFTER LNDG WHETHER TO RAISE OR LEAVE FLAPS DOWN WE LEFT THEM DOWN.