What was found
HYD 2 OFF LEVEL 1 IN CRUISE. FOLLOWED QRH. HYD SYNOPTIC SHOWED SYSTEM 2 FLUID QUANTITY DECREASING. FLUID LEVEL DECREASED BELOW 2.5 AND THEN RECEIVED LEVEL 2 HYD 2 FAIL. QUANTITY DROPPED TO 0.0. WHILE CONFIGURING TO LAND, RECEIVED LEVEL 2 FLAP DISAG AND FLAPS WOULD NOT EXTEND BEYOND 20 DEGREES. COMPLETED QRH AND LANDED WITHOUT FURTHER INCIDENT. ***EMERGENCY DECLARED*** REMOVED ACCESS PANEL 373CL FROM LH SIDE OF VERTICAL STAB TO FOM. FOUND LOWER B- NUT ON HYDRAULIC PIPE AMK7550-504 LOOSE. TIGHTENED B-NUT PER AMM 20-50-01-2. PERFORMED LEAK CHECK OF HYDRAULIC LINE AMK7550-504 LOWER B-NUT WITH HYRAULICS OPERATING. NO LEAKS FOUND.