What was found
FLT 6224 - PHL-IAD - DURING APPROACH, EXPERIENCED A DISCREPANCY WITH THE FLAP SELECTOR SYSTEMS. FLAPS SELECTED NOT LOCKING AT FLAPS 35 DEGREES. SELECTED 35 DEGREES, SELECTOR WENT FROM 35 DEGREES TO 20 DEGREES. AIRCRAFT LANDED AT IAD WITH NO INCIDENT REPORTED. MAINTENANCE TROUBLESHOT DISCREPANCY AND REMOVED AND REPLACED FAULTY FLAP HANDLE AND FUNCTIONALLY CHECKED SYSTEM IAW MX PROCEDURES. A/C WAS THEN RELEASED AND APPROVED FOR RETURN TO SERVICE. (M)