What was found
DTW - FLT 874 - ON CLIMB-OUT OF 8,000 FT, HEARD A LOUD BANG FROM REAR OF THE A/C. COULD NOT DETERMINE THE SOURCE, DECLARED AN EMERG AND RETURNED TO DTW. ALSO, EXPERIENCING UNCOMMANDED ROLL AND RUDDER FLUCTUATIONS WHICH INCREASED WITH SPEED ABOVE 10,000 FT. A/C WAS CLEAN, AIRFOIL AND ENG ANTI-ICE ON, THE YAW DAMPENER WAS ON, AUTO-PILOT WAS OFF. INSPECTED AIR CONDITIONING SYS AND DUCTING, INSPECTED AIL AND TAB IAW MM 27-10-0, INSPECT RUDDER AND TAB IAW MM 27-20-0, INSPECTED STAB TRIM IAW MM 27-40-1, INSPECTED ELEV AND TAB IAW MM 27-30-0, INSPECTED YAW DAMPENER IAW MM 22-11-0, INSPECTED SPOILER PANEL IAW MM 25-60-1, ALSO INSPECTED ENGS, MOUNTS, AND PYLONS. NO DEFECTS NOTED. COULD NOT LOCATE ANY DEFECTS ON A